Add aggregateAction; Add renderTemplateAction

qqq-backend-core/src/main/java/com/kingsrook/qqq/backend/core/actions/interfaces/AggregateInterface.java

@@ -0,0 +1,40 @@
+/*
+ * QQQ - Low-code Application Framework for Engineers.
+ * Copyright (C) 2021-2022.  Kingsrook, LLC
+ * 651 N Broad St Ste 205 # 6917 | Middletown DE 19709 | United States
+ * contact@kingsrook.com
+ * https://github.com/Kingsrook/
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU Affero General Public License as
+ * published by the Free Software Foundation, either version 3 of the
+ * License, or (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU Affero General Public License for more details.
+ *
+ * You should have received a copy of the GNU Affero General Public License
+ * along with this program.  If not, see <https://www.gnu.org/licenses/>.
+ */
+
+package com.kingsrook.qqq.backend.core.actions.interfaces;
+
+
+import com.kingsrook.qqq.backend.core.exceptions.QException;
+import com.kingsrook.qqq.backend.core.model.actions.tables.aggregate.AggregateInput;
+import com.kingsrook.qqq.backend.core.model.actions.tables.aggregate.AggregateOutput;
+
+
+/*******************************************************************************
+ ** Interface for the Aggregate action.
+ **
+ *******************************************************************************/
+public interface AggregateInterface
+{
+   /*******************************************************************************
+    **
+    *******************************************************************************/
+   AggregateOutput execute(AggregateInput aggregateInput) throws QException;
+}

qqq-backend-core/src/main/java/com/kingsrook/qqq/backend/core/actions/tables/AggregateAction.java

@@ -0,0 +1,53 @@
+/*
+ * QQQ - Low-code Application Framework for Engineers.
+ * Copyright (C) 2021-2022.  Kingsrook, LLC
+ * 651 N Broad St Ste 205 # 6917 | Middletown DE 19709 | United States
+ * contact@kingsrook.com
+ * https://github.com/Kingsrook/
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU Affero General Public License as
+ * published by the Free Software Foundation, either version 3 of the
+ * License, or (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU Affero General Public License for more details.
+ *
+ * You should have received a copy of the GNU Affero General Public License
+ * along with this program.  If not, see <https://www.gnu.org/licenses/>.
+ */
+
+package com.kingsrook.qqq.backend.core.actions.tables;
+
+
+import com.kingsrook.qqq.backend.core.actions.ActionHelper;
+import com.kingsrook.qqq.backend.core.exceptions.QException;
+import com.kingsrook.qqq.backend.core.model.actions.tables.aggregate.AggregateInput;
+import com.kingsrook.qqq.backend.core.model.actions.tables.aggregate.AggregateOutput;
+import com.kingsrook.qqq.backend.core.modules.backend.QBackendModuleDispatcher;
+import com.kingsrook.qqq.backend.core.modules.backend.QBackendModuleInterface;
+
+
+/*******************************************************************************
+ ** Action to run an aggregate against a table.
+ **
+ *******************************************************************************/
+public class AggregateAction
+{
+   /*******************************************************************************
+    **
+    *******************************************************************************/
+   public AggregateOutput execute(AggregateInput aggregateInput) throws QException
+   {
+      ActionHelper.validateSession(aggregateInput);
+
+      QBackendModuleDispatcher qBackendModuleDispatcher = new QBackendModuleDispatcher();
+      QBackendModuleInterface  qModule                  = qBackendModuleDispatcher.getQBackendModule(aggregateInput.getBackend());
+      // todo pre-customization - just get to modify the request?
+      AggregateOutput aggregateOutput = qModule.getAggregateInterface().execute(aggregateInput);
+      // todo post-customization - can do whatever w/ the result if you want
+      return aggregateOutput;
+   }
+}

qqq-backend-core/src/main/java/com/kingsrook/qqq/backend/core/actions/templates/RenderTemplateAction.java

@@ -0,0 +1,94 @@
+/*
+ * QQQ - Low-code Application Framework for Engineers.
+ * Copyright (C) 2021-2022.  Kingsrook, LLC
+ * 651 N Broad St Ste 205 # 6917 | Middletown DE 19709 | United States
+ * contact@kingsrook.com
+ * https://github.com/Kingsrook/
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU Affero General Public License as
+ * published by the Free Software Foundation, either version 3 of the
+ * License, or (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU Affero General Public License for more details.
+ *
+ * You should have received a copy of the GNU Affero General Public License
+ * along with this program.  If not, see <https://www.gnu.org/licenses/>.
+ */
+
+package com.kingsrook.qqq.backend.core.actions.templates;
+
+
+import java.io.StringWriter;
+import java.util.Map;
+import com.kingsrook.qqq.backend.core.actions.AbstractQActionFunction;
+import com.kingsrook.qqq.backend.core.exceptions.QException;
+import com.kingsrook.qqq.backend.core.model.actions.AbstractActionInput;
+import com.kingsrook.qqq.backend.core.model.templates.RenderTemplateInput;
+import com.kingsrook.qqq.backend.core.model.templates.RenderTemplateOutput;
+import com.kingsrook.qqq.backend.core.model.templates.TemplateType;
+import org.apache.velocity.VelocityContext;
+import org.apache.velocity.app.Velocity;
+import org.apache.velocity.context.Context;
+
+
+/*******************************************************************************
+ ** Basic action to render a template!
+ *******************************************************************************/
+public class RenderTemplateAction extends AbstractQActionFunction<RenderTemplateInput, RenderTemplateOutput>
+{
+
+   /*******************************************************************************
+    **
+    *******************************************************************************/
+   @Override
+   public RenderTemplateOutput execute(RenderTemplateInput input) throws QException
+   {
+      RenderTemplateOutput output = new RenderTemplateOutput();
+
+      if(TemplateType.VELOCITY.equals(input.getTemplateType()))
+      {
+         Velocity.init();
+         Context      context      = new VelocityContext(input.getContext());
+         StringWriter stringWriter = new StringWriter();
+         Velocity.evaluate(context, stringWriter, "logTag", input.getCode());
+         output.setResult(stringWriter.getBuffer().toString());
+      }
+      else
+      {
+         throw (new QException("Unsupported Template Type: " + input.getTemplateType()));
+      }
+
+      return (output);
+   }
+
+
+
+   /*******************************************************************************
+    ** Most convenient static wrapper to render a Velocity template.
+    *******************************************************************************/
+   public static String renderVelocity(AbstractActionInput parentActionInput, Map<String, Object> context, String code) throws QException
+   {
+      return (render(parentActionInput, TemplateType.VELOCITY, context, code));
+   }
+
+
+
+   /*******************************************************************************
+    ** Convenient static wrapper to render a template of an arbitrary type (language).
+    *******************************************************************************/
+   public static String render(AbstractActionInput parentActionInput, TemplateType templateType, Map<String, Object> context, String code) throws QException
+   {
+      RenderTemplateInput renderTemplateInput = new RenderTemplateInput(parentActionInput.getInstance());
+      renderTemplateInput.setSession(parentActionInput.getSession());
+      renderTemplateInput.setCode(code);
+      renderTemplateInput.setContext(context);
+      renderTemplateInput.setTemplateType(templateType);
+      RenderTemplateOutput output = new RenderTemplateAction().execute(renderTemplateInput);
+      return (output.getResult());
+   }
+
+}

qqq-backend-core/src/main/java/com/kingsrook/qqq/backend/core/instances/QInstanceEnricher.java

@@ -462,9 +462,25 @@ public class QInstanceEnricher
          .withTableName(table.getName())
          .withIsHidden(true);
 
-      List<QFieldMetaData> editableFields = table.getFields().values().stream()
+      List<QFieldMetaData> editableFields = new ArrayList<>();
-         .filter(QFieldMetaData::getIsEditable)
+      for(QFieldSection section : CollectionUtils.nonNullList(table.getSections()))
-         .toList();
+      {
+         for(String fieldName : CollectionUtils.nonNullList(section.getFieldNames()))
+         {
+            try
+            {
+               QFieldMetaData field = table.getField(fieldName);
+               if(field.getIsEditable())
+               {
+                  editableFields.add(field);
+               }
+            }
+            catch(Exception e)
+            {
+               // shrug?
+            }
+         }
+      }
 
       String fieldsForHelpText = editableFields.stream()
          .map(QFieldMetaData::getLabel)

qqq-backend-core/src/main/java/com/kingsrook/qqq/backend/core/instances/QInstanceValidator.java

@@ -114,6 +114,7 @@ public class QInstanceValidator
       }
       catch(Exception e)
       {
+         LOG.error("Error enriching instance prior to validation", e);
          throw (new QInstanceValidationException("Error enriching qInstance prior to validation.", e));
       }
 

qqq-backend-core/src/main/java/com/kingsrook/qqq/backend/core/model/actions/tables/aggregate/Aggregate.java

@@ -0,0 +1,156 @@
+/*
+ * QQQ - Low-code Application Framework for Engineers.
+ * Copyright (C) 2021-2022.  Kingsrook, LLC
+ * 651 N Broad St Ste 205 # 6917 | Middletown DE 19709 | United States
+ * contact@kingsrook.com
+ * https://github.com/Kingsrook/
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU Affero General Public License as
+ * published by the Free Software Foundation, either version 3 of the
+ * License, or (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU Affero General Public License for more details.
+ *
+ * You should have received a copy of the GNU Affero General Public License
+ * along with this program.  If not, see <https://www.gnu.org/licenses/>.
+ */
+
+package com.kingsrook.qqq.backend.core.model.actions.tables.aggregate;
+
+
+import java.io.Serializable;
+import java.util.Objects;
+
+
+/*******************************************************************************
+ **
+ *******************************************************************************/
+public class Aggregate implements Serializable
+{
+   private String            fieldName;
+   private AggregateOperator operator;
+
+
+
+   /*******************************************************************************
+    **
+    *******************************************************************************/
+   public Aggregate()
+   {
+   }
+
+
+
+   /*******************************************************************************
+    **
+    *******************************************************************************/
+   @Override
+   public boolean equals(Object o)
+   {
+      if(this == o)
+      {
+         return true;
+      }
+      if(o == null || getClass() != o.getClass())
+      {
+         return false;
+      }
+      Aggregate aggregate = (Aggregate) o;
+      return Objects.equals(fieldName, aggregate.fieldName) && operator == aggregate.operator;
+   }
+
+
+
+   /*******************************************************************************
+    **
+    *******************************************************************************/
+   @Override
+   public int hashCode()
+   {
+      return Objects.hash(fieldName, operator);
+   }
+
+
+
+   /*******************************************************************************
+    **
+    *******************************************************************************/
+   public Aggregate(String fieldName, AggregateOperator operator)
+   {
+      this.fieldName = fieldName;
+      this.operator = operator;
+   }
+
+
+
+   /*******************************************************************************
+    ** Getter for fieldName
+    **
+    *******************************************************************************/
+   public String getFieldName()
+   {
+      return fieldName;
+   }
+
+
+
+   /*******************************************************************************
+    ** Setter for fieldName
+    **
+    *******************************************************************************/
+   public void setFieldName(String fieldName)
+   {
+      this.fieldName = fieldName;
+   }
+
+
+
+   /*******************************************************************************
+    ** Fluent setter for fieldName
+    **
+    *******************************************************************************/
+   public Aggregate withFieldName(String fieldName)
+   {
+      this.fieldName = fieldName;
+      return (this);
+   }
+
+
+
+   /*******************************************************************************
+    ** Getter for operator
+    **
+    *******************************************************************************/
+   public AggregateOperator getOperator()
+   {
+      return operator;
+   }
+
+
+
+   /*******************************************************************************
+    ** Setter for operator
+    **
+    *******************************************************************************/
+   public void setOperator(AggregateOperator operator)
+   {
+      this.operator = operator;
+   }
+
+
+
+   /*******************************************************************************
+    ** Fluent setter for operator
+    **
+    *******************************************************************************/
+   public Aggregate withOperator(AggregateOperator operator)
+   {
+      this.operator = operator;
+      return (this);
+   }
+
+}

qqq-backend-core/src/main/java/com/kingsrook/qqq/backend/core/model/actions/tables/aggregate/AggregateInput.java

@@ -0,0 +1,195 @@
+/*
+ * QQQ - Low-code Application Framework for Engineers.
+ * Copyright (C) 2021-2022.  Kingsrook, LLC
+ * 651 N Broad St Ste 205 # 6917 | Middletown DE 19709 | United States
+ * contact@kingsrook.com
+ * https://github.com/Kingsrook/
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU Affero General Public License as
+ * published by the Free Software Foundation, either version 3 of the
+ * License, or (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU Affero General Public License for more details.
+ *
+ * You should have received a copy of the GNU Affero General Public License
+ * along with this program.  If not, see <https://www.gnu.org/licenses/>.
+ */
+
+package com.kingsrook.qqq.backend.core.model.actions.tables.aggregate;
+
+
+import java.util.ArrayList;
+import java.util.List;
+import com.kingsrook.qqq.backend.core.model.actions.AbstractTableActionInput;
+import com.kingsrook.qqq.backend.core.model.actions.tables.query.QQueryFilter;
+import com.kingsrook.qqq.backend.core.model.metadata.QInstance;
+
+
+/*******************************************************************************
+ ** Input data for the Count action
+ **
+ *******************************************************************************/
+public class AggregateInput extends AbstractTableActionInput
+{
+   private QQueryFilter    filter;
+   private List<Aggregate> aggregates;
+   private List<String>    groupByFieldNames;
+
+
+
+   /*******************************************************************************
+    **
+    *******************************************************************************/
+   public AggregateInput()
+   {
+   }
+
+
+
+   /*******************************************************************************
+    **
+    *******************************************************************************/
+   public AggregateInput(QInstance instance)
+   {
+      super(instance);
+   }
+
+
+
+   /*******************************************************************************
+    ** Getter for filter
+    **
+    *******************************************************************************/
+   public QQueryFilter getFilter()
+   {
+      return filter;
+   }
+
+
+
+   /*******************************************************************************
+    ** Setter for filter
+    **
+    *******************************************************************************/
+   public void setFilter(QQueryFilter filter)
+   {
+      this.filter = filter;
+   }
+
+
+
+   /*******************************************************************************
+    ** Fluent setter for filter
+    **
+    *******************************************************************************/
+   public AggregateInput withFilter(QQueryFilter filter)
+   {
+      setFilter(filter);
+      return (this);
+   }
+
+
+
+   /*******************************************************************************
+    ** Getter for aggregates
+    **
+    *******************************************************************************/
+   public List<Aggregate> getAggregates()
+   {
+      return aggregates;
+   }
+
+
+
+   /*******************************************************************************
+    ** Setter for aggregates
+    **
+    *******************************************************************************/
+   public void setAggregates(List<Aggregate> aggregates)
+   {
+      this.aggregates = aggregates;
+   }
+
+
+
+   /*******************************************************************************
+    ** Fluent setter for aggregates
+    **
+    *******************************************************************************/
+   public AggregateInput withAggregates(List<Aggregate> aggregates)
+   {
+      this.aggregates = aggregates;
+      return (this);
+   }
+
+
+
+   /*******************************************************************************
+    ** Fluent setter for aggregates
+    **
+    *******************************************************************************/
+   public AggregateInput withAggregate(Aggregate aggregate)
+   {
+      if(this.aggregates == null)
+      {
+         this.aggregates = new ArrayList<>();
+      }
+      this.aggregates.add(aggregate);
+      return (this);
+   }
+
+
+
+   /*******************************************************************************
+    ** Getter for groupByFieldNames
+    **
+    *******************************************************************************/
+   public List<String> getGroupByFieldNames()
+   {
+      return groupByFieldNames;
+   }
+
+
+
+   /*******************************************************************************
+    ** Setter for groupByFieldNames
+    **
+    *******************************************************************************/
+   public void setGroupByFieldNames(List<String> groupByFieldNames)
+   {
+      this.groupByFieldNames = groupByFieldNames;
+   }
+
+
+
+   /*******************************************************************************
+    ** Fluent setter for groupByFieldNames
+    **
+    *******************************************************************************/
+   public AggregateInput withGroupByFieldNames(List<String> groupByFieldNames)
+   {
+      this.groupByFieldNames = groupByFieldNames;
+      return (this);
+   }
+
+
+
+   /*******************************************************************************
+    ** Fluent setter for groupByFieldNames
+    **
+    *******************************************************************************/
+   public AggregateInput withGroupByFieldName(String groupByFieldName)
+   {
+      if(this.groupByFieldNames == null)
+      {
+         this.groupByFieldNames = new ArrayList<>();
+      }
+      this.groupByFieldNames.add(groupByFieldName);
+      return (this);
+   }
+
+}

qqq-backend-core/src/main/java/com/kingsrook/qqq/backend/core/model/actions/tables/aggregate/AggregateOperator.java

@@ -0,0 +1,35 @@
+/*
+ * QQQ - Low-code Application Framework for Engineers.
+ * Copyright (C) 2021-2022.  Kingsrook, LLC
+ * 651 N Broad St Ste 205 # 6917 | Middletown DE 19709 | United States
+ * contact@kingsrook.com
+ * https://github.com/Kingsrook/
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU Affero General Public License as
+ * published by the Free Software Foundation, either version 3 of the
+ * License, or (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU Affero General Public License for more details.
+ *
+ * You should have received a copy of the GNU Affero General Public License
+ * along with this program.  If not, see <https://www.gnu.org/licenses/>.
+ */
+
+package com.kingsrook.qqq.backend.core.model.actions.tables.aggregate;
+
+
+/*******************************************************************************
+ **
+ *******************************************************************************/
+public enum AggregateOperator
+{
+   COUNT,
+   SUM,
+   MIN,
+   MAX,
+   AVG
+}

qqq-backend-core/src/main/java/com/kingsrook/qqq/backend/core/model/actions/tables/aggregate/AggregateOutput.java

@@ -0,0 +1,59 @@
+/*
+ * QQQ - Low-code Application Framework for Engineers.
+ * Copyright (C) 2021-2022.  Kingsrook, LLC
+ * 651 N Broad St Ste 205 # 6917 | Middletown DE 19709 | United States
+ * contact@kingsrook.com
+ * https://github.com/Kingsrook/
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU Affero General Public License as
+ * published by the Free Software Foundation, either version 3 of the
+ * License, or (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU Affero General Public License for more details.
+ *
+ * You should have received a copy of the GNU Affero General Public License
+ * along with this program.  If not, see <https://www.gnu.org/licenses/>.
+ */
+
+package com.kingsrook.qqq.backend.core.model.actions.tables.aggregate;
+
+
+import java.util.List;
+import com.kingsrook.qqq.backend.core.model.actions.AbstractActionOutput;
+
+
+/*******************************************************************************
+ ** Output for an aggregate action
+ **
+ *******************************************************************************/
+public class AggregateOutput extends AbstractActionOutput
+{
+   private List<AggregateResult> results;
+
+
+
+   /*******************************************************************************
+    ** Getter for results
+    **
+    *******************************************************************************/
+   public List<AggregateResult> getResults()
+   {
+      return results;
+   }
+
+
+
+   /*******************************************************************************
+    ** Setter for results
+    **
+    *******************************************************************************/
+   public void setResults(List<AggregateResult> results)
+   {
+      this.results = results;
+   }
+
+}

qqq-backend-core/src/main/java/com/kingsrook/qqq/backend/core/model/actions/tables/aggregate/AggregateResult.java

@@ -0,0 +1,158 @@
+/*
+ * QQQ - Low-code Application Framework for Engineers.
+ * Copyright (C) 2021-2022.  Kingsrook, LLC
+ * 651 N Broad St Ste 205 # 6917 | Middletown DE 19709 | United States
+ * contact@kingsrook.com
+ * https://github.com/Kingsrook/
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU Affero General Public License as
+ * published by the Free Software Foundation, either version 3 of the
+ * License, or (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU Affero General Public License for more details.
+ *
+ * You should have received a copy of the GNU Affero General Public License
+ * along with this program.  If not, see <https://www.gnu.org/licenses/>.
+ */
+
+package com.kingsrook.qqq.backend.core.model.actions.tables.aggregate;
+
+
+import java.io.Serializable;
+import java.util.LinkedHashMap;
+import java.util.Map;
+
+
+/*******************************************************************************
+ **
+ *******************************************************************************/
+public class AggregateResult
+{
+   private Map<Aggregate, Serializable> aggregateValues = new LinkedHashMap<>();
+   private Map<String, Serializable>    groupByValues   = new LinkedHashMap<>();
+
+
+
+   /*******************************************************************************
+    ** Getter for aggregateValues
+    **
+    *******************************************************************************/
+   public Map<Aggregate, Serializable> getAggregateValues()
+   {
+      return aggregateValues;
+   }
+
+
+
+   /*******************************************************************************
+    ** Setter for aggregateValues
+    **
+    *******************************************************************************/
+   public void setAggregateValues(Map<Aggregate, Serializable> aggregateValues)
+   {
+      this.aggregateValues = aggregateValues;
+   }
+
+
+
+   /*******************************************************************************
+    ** Fluent setter for aggregateValues
+    **
+    *******************************************************************************/
+   public AggregateResult withAggregateValues(Map<Aggregate, Serializable> aggregateValues)
+   {
+      this.aggregateValues = aggregateValues;
+      return (this);
+   }
+
+
+
+   /*******************************************************************************
+    ** Fluent setter for groupByValues
+    **
+    *******************************************************************************/
+   public AggregateResult withAggregateValue(Aggregate aggregate, Serializable value)
+   {
+      if(this.aggregateValues == null)
+      {
+         this.aggregateValues = new LinkedHashMap<>();
+      }
+      this.aggregateValues.put(aggregate, value);
+      return (this);
+   }
+
+
+
+   /*******************************************************************************
+    **
+    *******************************************************************************/
+   public Serializable getAggregateValue(Aggregate aggregate)
+   {
+      return (this.aggregateValues.get(aggregate));
+   }
+
+
+
+   /*******************************************************************************
+    ** Getter for groupByValues
+    **
+    *******************************************************************************/
+   public Map<String, Serializable> getGroupByValues()
+   {
+      return groupByValues;
+   }
+
+
+
+   /*******************************************************************************
+    ** Setter for groupByValues
+    **
+    *******************************************************************************/
+   public void setGroupByValues(Map<String, Serializable> groupByValues)
+   {
+      this.groupByValues = groupByValues;
+   }
+
+
+
+   /*******************************************************************************
+    ** Fluent setter for groupByValues
+    **
+    *******************************************************************************/
+   public AggregateResult withGroupByValues(Map<String, Serializable> groupByValues)
+   {
+      this.groupByValues = groupByValues;
+      return (this);
+   }
+
+
+
+   /*******************************************************************************
+    ** Fluent setter for groupByValues
+    **
+    *******************************************************************************/
+   public AggregateResult withGroupByValue(String fieldName, Serializable value)
+   {
+      if(this.groupByValues == null)
+      {
+         this.groupByValues = new LinkedHashMap<>();
+      }
+      this.groupByValues.put(fieldName, value);
+      return (this);
+   }
+
+
+
+   /*******************************************************************************
+    **
+    *******************************************************************************/
+   public Serializable getGroupByValue(String fieldName)
+   {
+      return (this.groupByValues.get(fieldName));
+   }
+
+}

qqq-backend-core/src/main/java/com/kingsrook/qqq/backend/core/model/actions/tables/aggregate/QFilterOrderByAggregate.java

@@ -0,0 +1,123 @@
+/*
+ * QQQ - Low-code Application Framework for Engineers.
+ * Copyright (C) 2021-2022.  Kingsrook, LLC
+ * 651 N Broad St Ste 205 # 6917 | Middletown DE 19709 | United States
+ * contact@kingsrook.com
+ * https://github.com/Kingsrook/
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU Affero General Public License as
+ * published by the Free Software Foundation, either version 3 of the
+ * License, or (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU Affero General Public License for more details.
+ *
+ * You should have received a copy of the GNU Affero General Public License
+ * along with this program.  If not, see <https://www.gnu.org/licenses/>.
+ */
+
+package com.kingsrook.qqq.backend.core.model.actions.tables.aggregate;
+
+
+import com.kingsrook.qqq.backend.core.model.actions.tables.query.QFilterOrderBy;
+
+
+/*******************************************************************************
+ ** Bean representing an element of a query order-by clause - ordering by an
+ ** aggregate field.
+ **
+ *******************************************************************************/
+public class QFilterOrderByAggregate extends QFilterOrderBy implements Cloneable
+{
+   private Aggregate aggregate;
+
+
+
+   /*******************************************************************************
+    **
+    *******************************************************************************/
+   @Override
+   public QFilterOrderByAggregate clone()
+   {
+      return (QFilterOrderByAggregate) super.clone();
+   }
+
+
+
+   /*******************************************************************************
+    ** Default no-arg constructor
+    *******************************************************************************/
+   public QFilterOrderByAggregate()
+   {
+
+   }
+
+
+
+   /*******************************************************************************
+    ** Constructor that sets field name, but leaves default for isAscending (true)
+    *******************************************************************************/
+   public QFilterOrderByAggregate(Aggregate aggregate)
+   {
+      this.aggregate = aggregate;
+   }
+
+
+
+   /*******************************************************************************
+    ** Constructor that takes field name and isAscending.
+    *******************************************************************************/
+   public QFilterOrderByAggregate(Aggregate aggregate, boolean isAscending)
+   {
+      this.aggregate = aggregate;
+      setIsAscending(isAscending);
+   }
+
+
+
+   /*******************************************************************************
+    ** Getter for aggregate
+    **
+    *******************************************************************************/
+   public Aggregate getAggregate()
+   {
+      return aggregate;
+   }
+
+
+
+   /*******************************************************************************
+    ** Setter for aggregate
+    **
+    *******************************************************************************/
+   public void setAggregate(Aggregate aggregate)
+   {
+      this.aggregate = aggregate;
+   }
+
+
+
+   /*******************************************************************************
+    ** Fluent setter for aggregate
+    **
+    *******************************************************************************/
+   public QFilterOrderByAggregate withAggregate(Aggregate aggregate)
+   {
+      this.aggregate = aggregate;
+      return (this);
+   }
+
+
+
+   /*******************************************************************************
+    **
+    *******************************************************************************/
+   @Override
+   public String toString()
+   {
+      return (aggregate + " " + (getIsAscending() ? "ASC" : "DESC"));
+   }
+}

qqq-backend-core/src/main/java/com/kingsrook/qqq/backend/core/model/actions/tables/query/QFilterCriteria.java

@@ -24,6 +24,7 @@ package com.kingsrook.qqq.backend.core.model.actions.tables.query;
 
 import java.io.Serializable;
 import java.util.ArrayList;
+import java.util.Arrays;
 import java.util.List;
 import com.kingsrook.qqq.backend.core.utils.CollectionUtils;
 import org.apache.logging.log4j.LogManager;
@@ -73,6 +74,10 @@ public class QFilterCriteria implements Serializable, Cloneable
     *******************************************************************************/
    public QFilterCriteria()
    {
+      ///////////////////////////////
+      // don't let values be null. //
+      ///////////////////////////////
+      values = new ArrayList<>();
    }
 
 
@@ -84,7 +89,31 @@ public class QFilterCriteria implements Serializable, Cloneable
    {
       this.fieldName = fieldName;
       this.operator = operator;
-      this.values = values;
+      this.values = values == null ? new ArrayList<>() : values;
+   }
+
+
+
+   /*******************************************************************************
+    **
+    *******************************************************************************/
+   public QFilterCriteria(String fieldName, QCriteriaOperator operator, Serializable... values)
+   {
+      this.fieldName = fieldName;
+      this.operator = operator;
+
+      if(values == null || (values.length == 1 && values[0] == null))
+      {
+         ////////////////////////////////////////////////////////////////////
+         // this ... could be a sign of an issue... debug juuuust in case? //
+         ////////////////////////////////////////////////////////////////////
+         LOG.debug("null passed as singleton varargs array will be ignored");
+         this.values = new ArrayList<>();
+      }
+      else
+      {
+         this.values = Arrays.stream(values).toList();
+      }
    }
 
 

qqq-backend-core/src/main/java/com/kingsrook/qqq/backend/core/model/actions/tables/query/QQueryFilter.java

@@ -24,6 +24,7 @@ package com.kingsrook.qqq.backend.core.model.actions.tables.query;
 
 import java.io.Serializable;
 import java.util.ArrayList;
+import java.util.Arrays;
 import java.util.List;
 import com.kingsrook.qqq.backend.core.utils.CollectionUtils;
 import org.apache.logging.log4j.LogManager;
@@ -57,6 +58,27 @@ public class QQueryFilter implements Serializable, Cloneable
 
 
 
+   /*******************************************************************************
+    ** Constructor
+    **
+    *******************************************************************************/
+   public QQueryFilter()
+   {
+   }
+
+
+
+   /*******************************************************************************
+    ** Constructor
+    **
+    *******************************************************************************/
+   public QQueryFilter(QFilterCriteria... criteria)
+   {
+      this.criteria = new ArrayList<>(Arrays.stream(criteria).toList());
+   }
+
+
+
    /*******************************************************************************
     **
     *******************************************************************************/

qqq-backend-core/src/main/java/com/kingsrook/qqq/backend/core/model/templates/RenderTemplateInput.java

@@ -0,0 +1,152 @@
+/*
+ * QQQ - Low-code Application Framework for Engineers.
+ * Copyright (C) 2021-2022.  Kingsrook, LLC
+ * 651 N Broad St Ste 205 # 6917 | Middletown DE 19709 | United States
+ * contact@kingsrook.com
+ * https://github.com/Kingsrook/
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU Affero General Public License as
+ * published by the Free Software Foundation, either version 3 of the
+ * License, or (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU Affero General Public License for more details.
+ *
+ * You should have received a copy of the GNU Affero General Public License
+ * along with this program.  If not, see <https://www.gnu.org/licenses/>.
+ */
+
+package com.kingsrook.qqq.backend.core.model.templates;
+
+
+import java.util.Map;
+import com.kingsrook.qqq.backend.core.model.actions.AbstractActionInput;
+import com.kingsrook.qqq.backend.core.model.metadata.QInstance;
+
+
+/*******************************************************************************
+ **
+ *******************************************************************************/
+public class RenderTemplateInput extends AbstractActionInput
+{
+   private String       code; // todo - TemplateReference, like CodeReference??
+   private TemplateType templateType;
+
+   private Map<String, Object> context;
+
+
+
+   /*******************************************************************************
+    **
+    *******************************************************************************/
+   public RenderTemplateInput(QInstance instance)
+   {
+      super(instance);
+   }
+
+
+
+   /*******************************************************************************
+    ** Getter for code
+    **
+    *******************************************************************************/
+   public String getCode()
+   {
+      return code;
+   }
+
+
+
+   /*******************************************************************************
+    ** Setter for code
+    **
+    *******************************************************************************/
+   public void setCode(String code)
+   {
+      this.code = code;
+   }
+
+
+
+   /*******************************************************************************
+    ** Fluent setter for code
+    **
+    *******************************************************************************/
+   public RenderTemplateInput withCode(String code)
+   {
+      this.code = code;
+      return (this);
+   }
+
+
+
+   /*******************************************************************************
+    ** Getter for templateType
+    **
+    *******************************************************************************/
+   public TemplateType getTemplateType()
+   {
+      return templateType;
+   }
+
+
+
+   /*******************************************************************************
+    ** Setter for templateType
+    **
+    *******************************************************************************/
+   public void setTemplateType(TemplateType templateType)
+   {
+      this.templateType = templateType;
+   }
+
+
+
+   /*******************************************************************************
+    ** Fluent setter for templateType
+    **
+    *******************************************************************************/
+   public RenderTemplateInput withTemplateType(TemplateType templateType)
+   {
+      this.templateType = templateType;
+      return (this);
+   }
+
+
+
+   /*******************************************************************************
+    ** Getter for context
+    **
+    *******************************************************************************/
+   public Map<String, Object> getContext()
+   {
+      return context;
+   }
+
+
+
+   /*******************************************************************************
+    ** Setter for context
+    **
+    *******************************************************************************/
+   public void setContext(Map<String, Object> context)
+   {
+      this.context = context;
+   }
+
+
+
+   /*******************************************************************************
+    ** Fluent setter for context
+    **
+    *******************************************************************************/
+   public RenderTemplateInput withContext(Map<String, Object> context)
+   {
+      this.context = context;
+      return (this);
+   }
+
+}

qqq-backend-core/src/main/java/com/kingsrook/qqq/backend/core/model/templates/RenderTemplateOutput.java

@@ -0,0 +1,69 @@
+/*
+ * QQQ - Low-code Application Framework for Engineers.
+ * Copyright (C) 2021-2022.  Kingsrook, LLC
+ * 651 N Broad St Ste 205 # 6917 | Middletown DE 19709 | United States
+ * contact@kingsrook.com
+ * https://github.com/Kingsrook/
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU Affero General Public License as
+ * published by the Free Software Foundation, either version 3 of the
+ * License, or (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU Affero General Public License for more details.
+ *
+ * You should have received a copy of the GNU Affero General Public License
+ * along with this program.  If not, see <https://www.gnu.org/licenses/>.
+ */
+
+package com.kingsrook.qqq.backend.core.model.templates;
+
+
+import com.kingsrook.qqq.backend.core.model.actions.AbstractActionOutput;
+
+
+/*******************************************************************************
+ **
+ *******************************************************************************/
+public class RenderTemplateOutput extends AbstractActionOutput
+{
+   private String result;
+
+
+
+   /*******************************************************************************
+    ** Getter for result
+    **
+    *******************************************************************************/
+   public String getResult()
+   {
+      return result;
+   }
+
+
+
+   /*******************************************************************************
+    ** Setter for result
+    **
+    *******************************************************************************/
+   public void setResult(String result)
+   {
+      this.result = result;
+   }
+
+
+
+   /*******************************************************************************
+    ** Fluent setter for result
+    **
+    *******************************************************************************/
+   public RenderTemplateOutput withResult(String result)
+   {
+      this.result = result;
+      return (this);
+   }
+
+}

qqq-backend-core/src/main/java/com/kingsrook/qqq/backend/core/model/templates/TemplateType.java

@@ -0,0 +1,31 @@
+/*
+ * QQQ - Low-code Application Framework for Engineers.
+ * Copyright (C) 2021-2022.  Kingsrook, LLC
+ * 651 N Broad St Ste 205 # 6917 | Middletown DE 19709 | United States
+ * contact@kingsrook.com
+ * https://github.com/Kingsrook/
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU Affero General Public License as
+ * published by the Free Software Foundation, either version 3 of the
+ * License, or (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU Affero General Public License for more details.
+ *
+ * You should have received a copy of the GNU Affero General Public License
+ * along with this program.  If not, see <https://www.gnu.org/licenses/>.
+ */
+
+package com.kingsrook.qqq.backend.core.model.templates;
+
+
+/*******************************************************************************
+ **
+ *******************************************************************************/
+public enum TemplateType
+{
+   VELOCITY
+}

qqq-backend-core/src/main/java/com/kingsrook/qqq/backend/core/modules/backend/QBackendModuleInterface.java

@@ -22,6 +22,7 @@
 package com.kingsrook.qqq.backend.core.modules.backend;
 
 
+import com.kingsrook.qqq.backend.core.actions.interfaces.AggregateInterface;
 import com.kingsrook.qqq.backend.core.actions.interfaces.CountInterface;
 import com.kingsrook.qqq.backend.core.actions.interfaces.DeleteInterface;
 import com.kingsrook.qqq.backend.core.actions.interfaces.GetInterface;
@@ -116,6 +117,15 @@ public interface QBackendModuleInterface
       return null;
    }
 
+   /*******************************************************************************
+    **
+    *******************************************************************************/
+   default AggregateInterface getAggregateInterface()
+   {
+      throwNotImplemented("Aggregate");
+      return null;
+   }
+
    /*******************************************************************************
     **
     *******************************************************************************/

qqq-backend-core/src/test/java/com/kingsrook/qqq/backend/core/actions/templates/RenderTemplateActionTest.java

@@ -0,0 +1,96 @@
+/*
+ * QQQ - Low-code Application Framework for Engineers.
+ * Copyright (C) 2021-2022.  Kingsrook, LLC
+ * 651 N Broad St Ste 205 # 6917 | Middletown DE 19709 | United States
+ * contact@kingsrook.com
+ * https://github.com/Kingsrook/
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU Affero General Public License as
+ * published by the Free Software Foundation, either version 3 of the
+ * License, or (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU Affero General Public License for more details.
+ *
+ * You should have received a copy of the GNU Affero General Public License
+ * along with this program.  If not, see <https://www.gnu.org/licenses/>.
+ */
+
+package com.kingsrook.qqq.backend.core.actions.templates;
+
+
+import java.util.Map;
+import com.kingsrook.qqq.backend.core.exceptions.QException;
+import com.kingsrook.qqq.backend.core.model.session.QSession;
+import com.kingsrook.qqq.backend.core.model.templates.RenderTemplateInput;
+import com.kingsrook.qqq.backend.core.model.templates.RenderTemplateOutput;
+import com.kingsrook.qqq.backend.core.model.templates.TemplateType;
+import com.kingsrook.qqq.backend.core.utils.TestUtils;
+import org.junit.jupiter.api.Test;
+import static org.assertj.core.api.Assertions.assertThatThrownBy;
+import static org.junit.jupiter.api.Assertions.assertEquals;
+
+
+/*******************************************************************************
+ ** Unit test for RenderTemplateAction
+ *******************************************************************************/
+class RenderTemplateActionTest
+{
+
+   /*******************************************************************************
+    **
+    *******************************************************************************/
+   @Test
+   void test() throws QException
+   {
+      RenderTemplateInput renderTemplateInput = new RenderTemplateInput(TestUtils.defineInstance());
+      renderTemplateInput.setSession(new QSession());
+      renderTemplateInput.setCode("""
+         Hello, $name""");
+      renderTemplateInput.setContext(Map.of("name", "Darin"));
+      renderTemplateInput.setTemplateType(TemplateType.VELOCITY);
+      RenderTemplateOutput output = new RenderTemplateAction().execute(renderTemplateInput);
+      assertEquals("Hello, Darin", output.getResult());
+   }
+
+
+
+   /*******************************************************************************
+    **
+    *******************************************************************************/
+   @Test
+   void testConvenientWrapper() throws QException
+   {
+      RenderTemplateInput parentActionInput = new RenderTemplateInput(TestUtils.defineInstance());
+      parentActionInput.setSession(new QSession());
+
+      String template = "Hello, $name";
+      assertEquals("Hello, Darin", RenderTemplateAction.renderVelocity(parentActionInput, Map.of("name", "Darin"), template));
+      assertEquals("Hello, Tim", RenderTemplateAction.renderVelocity(parentActionInput, Map.of("name", "Tim"), template));
+      assertEquals("Hello, $name", RenderTemplateAction.renderVelocity(parentActionInput, Map.of(), template));
+
+      template = "Hello, $!name";
+      assertEquals("Hello, ", RenderTemplateAction.renderVelocity(parentActionInput, Map.of(), template));
+      assertEquals("Hello, ", RenderTemplateAction.renderVelocity(parentActionInput, null, template));
+   }
+
+
+
+   /*******************************************************************************
+    **
+    *******************************************************************************/
+   @Test
+   void testMissingType()
+   {
+      RenderTemplateInput parentActionInput = new RenderTemplateInput(TestUtils.defineInstance());
+      parentActionInput.setSession(new QSession());
+
+      assertThatThrownBy(() -> RenderTemplateAction.render(parentActionInput, null, Map.of("name", "Darin"), "Hello, $name"))
+         .isInstanceOf(QException.class)
+         .hasMessageContaining("Unsupported Template Type");
+   }
+
+}

qqq-backend-core/src/test/java/com/kingsrook/qqq/backend/core/model/actions/tables/query/QFilterCriteriaTest.java

@@ -0,0 +1,75 @@
+/*
+ * QQQ - Low-code Application Framework for Engineers.
+ * Copyright (C) 2021-2022.  Kingsrook, LLC
+ * 651 N Broad St Ste 205 # 6917 | Middletown DE 19709 | United States
+ * contact@kingsrook.com
+ * https://github.com/Kingsrook/
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU Affero General Public License as
+ * published by the Free Software Foundation, either version 3 of the
+ * License, or (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU Affero General Public License for more details.
+ *
+ * You should have received a copy of the GNU Affero General Public License
+ * along with this program.  If not, see <https://www.gnu.org/licenses/>.
+ */
+
+package com.kingsrook.qqq.backend.core.model.actions.tables.query;
+
+
+import java.io.Serializable;
+import java.util.ArrayList;
+import java.util.List;
+import org.junit.jupiter.api.Test;
+import static com.kingsrook.qqq.backend.core.model.actions.tables.query.QCriteriaOperator.EQUALS;
+import static com.kingsrook.qqq.backend.core.model.actions.tables.query.QCriteriaOperator.IS_BLANK;
+import static org.junit.jupiter.api.Assertions.assertEquals;
+
+
+/*******************************************************************************
+ ** Unit test for QFilterCriteria
+ *******************************************************************************/
+class QFilterCriteriaTest
+{
+
+   /*******************************************************************************
+    ** Make sure that the constructors that takes a List or Serializable... and does
+    ** the right thing - e.g., never making a List-of-List, or List of array, and
+    ** that we never have null values - always an empty list as the degenerate case.
+    *******************************************************************************/
+   @Test
+   void test()
+   {
+      assertEquals(1, new QFilterCriteria("foo", EQUALS, "A").getValues().size());
+      assertEquals(1, new QFilterCriteria("foo", EQUALS, List.of("A")).getValues().size());
+      assertEquals(2, new QFilterCriteria("foo", EQUALS, List.of("A", "B")).getValues().size());
+      assertEquals(2, new QFilterCriteria("foo", EQUALS, "A", "B").getValues().size());
+
+      List<Serializable> list = List.of("A", "B", "C");
+      assertEquals(3, new QFilterCriteria("foo", EQUALS, list).getValues().size());
+      assertEquals(List.of("A", "B", "C"), new QFilterCriteria("foo", EQUALS, list).getValues());
+
+      Serializable[] array = new Serializable[] { "A", "B", "C", "D" };
+      assertEquals(4, new QFilterCriteria("foo", EQUALS, array).getValues().size());
+      assertEquals(List.of("A", "B", "C", "D"), new QFilterCriteria("foo", EQUALS, array).getValues());
+
+      assertEquals(3, new QFilterCriteria("foo", EQUALS, new ArrayList<>(list)).getValues().size());
+      assertEquals(List.of("A", "B", "C"), new QFilterCriteria("foo", EQUALS, new ArrayList<>(list)).getValues());
+
+      assertEquals(0, new QFilterCriteria("foo", IS_BLANK).getValues().size());
+
+      Serializable maybeNull = null;
+      assertEquals(0, new QFilterCriteria("foo", EQUALS, maybeNull).getValues().size());
+
+      List<Serializable> nullList = null;
+      assertEquals(0, new QFilterCriteria("foo", EQUALS, nullList).getValues().size());
+
+      assertEquals(0, new QFilterCriteria("foo", EQUALS, (List<Serializable>) null).getValues().size());
+   }
+
+}

qqq-backend-module-rdbms/src/main/java/com/kingsrook/qqq/backend/module/rdbms/RDBMSBackendModule.java

@@ -22,6 +22,7 @@
 package com.kingsrook.qqq.backend.module.rdbms;
 
 
+import com.kingsrook.qqq.backend.core.actions.interfaces.AggregateInterface;
 import com.kingsrook.qqq.backend.core.actions.interfaces.CountInterface;
 import com.kingsrook.qqq.backend.core.actions.interfaces.DeleteInterface;
 import com.kingsrook.qqq.backend.core.actions.interfaces.InsertInterface;
@@ -30,6 +31,7 @@ import com.kingsrook.qqq.backend.core.actions.interfaces.UpdateInterface;
 import com.kingsrook.qqq.backend.core.model.metadata.QBackendMetaData;
 import com.kingsrook.qqq.backend.core.model.metadata.tables.QTableBackendDetails;
 import com.kingsrook.qqq.backend.core.modules.backend.QBackendModuleInterface;
+import com.kingsrook.qqq.backend.module.rdbms.actions.RDBMSAggregateAction;
 import com.kingsrook.qqq.backend.module.rdbms.actions.RDBMSCountAction;
 import com.kingsrook.qqq.backend.module.rdbms.actions.RDBMSDeleteAction;
 import com.kingsrook.qqq.backend.module.rdbms.actions.RDBMSInsertAction;
@@ -87,7 +89,6 @@ public class RDBMSBackendModule implements QBackendModuleInterface
 
 
 
-
    /*******************************************************************************
     **
     *******************************************************************************/
@@ -130,4 +131,15 @@ public class RDBMSBackendModule implements QBackendModuleInterface
       return (new RDBMSDeleteAction());
    }
 
+
+
+   /*******************************************************************************
+    **
+    *******************************************************************************/
+   @Override
+   public AggregateInterface getAggregateInterface()
+   {
+      return (new RDBMSAggregateAction());
+   }
+
 }

qqq-backend-module-rdbms/src/main/java/com/kingsrook/qqq/backend/module/rdbms/actions/AbstractRDBMSAction.java

@@ -24,6 +24,7 @@ package com.kingsrook.qqq.backend.module.rdbms.actions;
 
 import java.io.Serializable;
 import java.sql.Connection;
+import java.sql.ResultSet;
 import java.sql.SQLException;
 import java.util.ArrayList;
 import java.util.List;
@@ -33,7 +34,10 @@ import com.kingsrook.qqq.backend.core.actions.QBackendTransaction;
 import com.kingsrook.qqq.backend.core.actions.interfaces.QActionInterface;
 import com.kingsrook.qqq.backend.core.exceptions.QException;
 import com.kingsrook.qqq.backend.core.model.actions.AbstractTableActionInput;
+import com.kingsrook.qqq.backend.core.model.actions.tables.aggregate.Aggregate;
+import com.kingsrook.qqq.backend.core.model.actions.tables.aggregate.QFilterOrderByAggregate;
 import com.kingsrook.qqq.backend.core.model.actions.tables.query.QFilterCriteria;
+import com.kingsrook.qqq.backend.core.model.actions.tables.query.QFilterOrderBy;
 import com.kingsrook.qqq.backend.core.model.actions.tables.query.QQueryFilter;
 import com.kingsrook.qqq.backend.core.model.data.QRecord;
 import com.kingsrook.qqq.backend.core.model.metadata.fields.QFieldMetaData;
@@ -43,6 +47,7 @@ import com.kingsrook.qqq.backend.core.utils.CollectionUtils;
 import com.kingsrook.qqq.backend.core.utils.StringUtils;
 import com.kingsrook.qqq.backend.core.utils.ValueUtils;
 import com.kingsrook.qqq.backend.module.rdbms.jdbc.ConnectionManager;
+import com.kingsrook.qqq.backend.module.rdbms.jdbc.QueryManager;
 import com.kingsrook.qqq.backend.module.rdbms.model.metadata.RDBMSBackendMetaData;
 import com.kingsrook.qqq.backend.module.rdbms.model.metadata.RDBMSTableBackendDetails;
 import org.apache.logging.log4j.LogManager;
@@ -411,4 +416,80 @@ public abstract class AbstractRDBMSAction implements QActionInterface
       return ("`" + id + "`");
    }
 
+
+
+   /*******************************************************************************
+    **
+    *******************************************************************************/
+   protected Serializable getFieldValueFromResultSet(QFieldMetaData qFieldMetaData, ResultSet resultSet, int i) throws SQLException
+   {
+      switch(qFieldMetaData.getType())
+      {
+         case STRING:
+         case TEXT:
+         case HTML:
+         case PASSWORD:
+         {
+            return (QueryManager.getString(resultSet, i));
+         }
+         case INTEGER:
+         {
+            return (QueryManager.getInteger(resultSet, i));
+         }
+         case DECIMAL:
+         {
+            return (QueryManager.getBigDecimal(resultSet, i));
+         }
+         case DATE:
+         {
+            // todo - queryManager.getLocalDate?
+            return (QueryManager.getDate(resultSet, i));
+         }
+         case TIME:
+         {
+            return (QueryManager.getLocalTime(resultSet, i));
+         }
+         case DATE_TIME:
+         {
+            return (QueryManager.getInstant(resultSet, i));
+         }
+         case BOOLEAN:
+         {
+            return (QueryManager.getBoolean(resultSet, i));
+         }
+         default:
+         {
+            throw new IllegalStateException("Unexpected field type: " + qFieldMetaData.getType());
+         }
+      }
+
+   }
+
+
+
+   /*******************************************************************************
+    **
+    *******************************************************************************/
+   protected String makeOrderByClause(QTableMetaData table, List<QFilterOrderBy> orderBys)
+   {
+      List<String> clauses = new ArrayList<>();
+
+      for(QFilterOrderBy orderBy : orderBys)
+      {
+         String ascOrDesc = orderBy.getIsAscending() ? "ASC" : "DESC";
+         if(orderBy instanceof QFilterOrderByAggregate orderByAggregate)
+         {
+            Aggregate aggregate = orderByAggregate.getAggregate();
+            String    clause    = (aggregate.getOperator() + "(" + escapeIdentifier(getColumnName(table.getField(aggregate.getFieldName()))) + ")");
+            clauses.add(clause + " " + ascOrDesc);
+         }
+         else
+         {
+            QFieldMetaData field  = table.getField(orderBy.getFieldName());
+            String         column = escapeIdentifier(getColumnName(field));
+            clauses.add(column + " " + ascOrDesc);
+         }
+      }
+      return (String.join(", ", clauses));
+   }
 }

qqq-backend-module-rdbms/src/main/java/com/kingsrook/qqq/backend/module/rdbms/actions/RDBMSAggregateAction.java

@@ -0,0 +1,176 @@
+/*
+ * QQQ - Low-code Application Framework for Engineers.
+ * Copyright (C) 2021-2022.  Kingsrook, LLC
+ * 651 N Broad St Ste 205 # 6917 | Middletown DE 19709 | United States
+ * contact@kingsrook.com
+ * https://github.com/Kingsrook/
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU Affero General Public License as
+ * published by the Free Software Foundation, either version 3 of the
+ * License, or (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU Affero General Public License for more details.
+ *
+ * You should have received a copy of the GNU Affero General Public License
+ * along with this program.  If not, see <https://www.gnu.org/licenses/>.
+ */
+
+package com.kingsrook.qqq.backend.module.rdbms.actions;
+
+
+import java.io.Serializable;
+import java.sql.Connection;
+import java.sql.ResultSet;
+import java.util.ArrayList;
+import java.util.List;
+import com.kingsrook.qqq.backend.core.actions.interfaces.AggregateInterface;
+import com.kingsrook.qqq.backend.core.exceptions.QException;
+import com.kingsrook.qqq.backend.core.model.actions.tables.aggregate.Aggregate;
+import com.kingsrook.qqq.backend.core.model.actions.tables.aggregate.AggregateInput;
+import com.kingsrook.qqq.backend.core.model.actions.tables.aggregate.AggregateOperator;
+import com.kingsrook.qqq.backend.core.model.actions.tables.aggregate.AggregateOutput;
+import com.kingsrook.qqq.backend.core.model.actions.tables.aggregate.AggregateResult;
+import com.kingsrook.qqq.backend.core.model.actions.tables.query.QQueryFilter;
+import com.kingsrook.qqq.backend.core.model.metadata.fields.QFieldMetaData;
+import com.kingsrook.qqq.backend.core.model.metadata.fields.QFieldType;
+import com.kingsrook.qqq.backend.core.model.metadata.tables.QTableMetaData;
+import com.kingsrook.qqq.backend.core.utils.CollectionUtils;
+import com.kingsrook.qqq.backend.core.utils.StringUtils;
+import com.kingsrook.qqq.backend.module.rdbms.jdbc.QueryManager;
+import org.apache.logging.log4j.LogManager;
+import org.apache.logging.log4j.Logger;
+
+
+/*******************************************************************************
+ **
+ *******************************************************************************/
+public class RDBMSAggregateAction extends AbstractRDBMSAction implements AggregateInterface
+{
+   private static final Logger LOG = LogManager.getLogger(RDBMSAggregateAction.class);
+
+
+
+   /*******************************************************************************
+    **
+    *******************************************************************************/
+   public AggregateOutput execute(AggregateInput aggregateInput) throws QException
+   {
+      try
+      {
+         QTableMetaData table     = aggregateInput.getTable();
+         String         tableName = getTableName(table);
+
+         List<String> selectClauses = buildSelectClauses(aggregateInput);
+
+         String sql = "SELECT " + StringUtils.join(", ", selectClauses)
+            + " FROM " + escapeIdentifier(tableName);
+
+         QQueryFilter       filter = aggregateInput.getFilter();
+         List<Serializable> params = new ArrayList<>();
+         if(filter != null && filter.hasAnyCriteria())
+         {
+            sql += " WHERE " + makeWhereClause(table, filter, params);
+         }
+
+         if(CollectionUtils.nullSafeHasContents(aggregateInput.getGroupByFieldNames()))
+         {
+            sql += " GROUP BY " + makeGroupByClause(aggregateInput);
+         }
+
+         if(filter != null && CollectionUtils.nullSafeHasContents(filter.getOrderBys()))
+         {
+            sql += " ORDER BY " + makeOrderByClause(table, filter.getOrderBys());
+         }
+
+         // todo sql customization - can edit sql and/or param list
+         LOG.debug(sql); // todo not commit - downgrade to trace
+
+         AggregateOutput       rs      = new AggregateOutput();
+         List<AggregateResult> results = new ArrayList<>();
+         rs.setResults(results);
+
+         try(Connection connection = getConnection(aggregateInput))
+         {
+            QueryManager.executeStatement(connection, sql, ((ResultSet resultSet) ->
+            {
+               while(resultSet.next())
+               {
+                  AggregateResult result = new AggregateResult();
+                  results.add(result);
+
+                  int selectionIndex = 1;
+                  for(String groupByFieldName : CollectionUtils.nonNullList(aggregateInput.getGroupByFieldNames()))
+                  {
+                     Serializable value = getFieldValueFromResultSet(table.getField(groupByFieldName), resultSet, selectionIndex++);
+                     result.withGroupByValue(groupByFieldName, value);
+                  }
+
+                  for(Aggregate aggregate : aggregateInput.getAggregates())
+                  {
+                     QFieldMetaData field = table.getField(aggregate.getFieldName());
+                     if(field.getType().equals(QFieldType.INTEGER) && aggregate.getOperator().equals(AggregateOperator.AVG))
+                     {
+                        field = new QFieldMetaData().withType(QFieldType.DECIMAL);
+                     }
+
+                     Serializable value = getFieldValueFromResultSet(field, resultSet, selectionIndex++);
+                     result.withAggregateValue(aggregate, value);
+                  }
+               }
+
+            }), params);
+         }
+
+         return rs;
+      }
+      catch(Exception e)
+      {
+         LOG.warn("Error executing aggregate", e);
+         throw new QException("Error executing aggregate", e);
+      }
+   }
+
+
+
+   /*******************************************************************************
+    **
+    *******************************************************************************/
+   private List<String> buildSelectClauses(AggregateInput aggregateInput)
+   {
+      QTableMetaData table = aggregateInput.getTable();
+      List<String>   rs    = new ArrayList<>();
+
+      for(String groupByFieldName : CollectionUtils.nonNullList(aggregateInput.getGroupByFieldNames()))
+      {
+         rs.add(escapeIdentifier(getColumnName(table.getField(groupByFieldName))));
+      }
+
+      for(Aggregate aggregate : aggregateInput.getAggregates())
+      {
+         rs.add(aggregate.getOperator() + "(" + escapeIdentifier(getColumnName(table.getField(aggregate.getFieldName()))) + ")");
+      }
+      return (rs);
+   }
+
+
+
+   /*******************************************************************************
+    **
+    *******************************************************************************/
+   private String makeGroupByClause(AggregateInput aggregateInput)
+   {
+      QTableMetaData table   = aggregateInput.getTable();
+      List<String>   columns = new ArrayList<>();
+      for(String groupByFieldName : aggregateInput.getGroupByFieldNames())
+      {
+         columns.add(escapeIdentifier(getColumnName(table.getField(groupByFieldName))));
+      }
+
+      return (StringUtils.join(",", columns));
+   }
+
+}

qqq-backend-module-rdbms/src/main/java/com/kingsrook/qqq/backend/module/rdbms/actions/RDBMSQueryAction.java

@@ -34,7 +34,6 @@ import java.util.List;
 import java.util.stream.Collectors;
 import com.kingsrook.qqq.backend.core.actions.interfaces.QueryInterface;
 import com.kingsrook.qqq.backend.core.exceptions.QException;
-import com.kingsrook.qqq.backend.core.model.actions.tables.query.QFilterOrderBy;
 import com.kingsrook.qqq.backend.core.model.actions.tables.query.QQueryFilter;
 import com.kingsrook.qqq.backend.core.model.actions.tables.query.QueryInput;
 import com.kingsrook.qqq.backend.core.model.actions.tables.query.QueryOutput;
@@ -129,7 +128,7 @@ public class RDBMSQueryAction extends AbstractRDBMSAction implements QueryInterf
                   for(int i = 1; i <= metaData.getColumnCount(); i++)
                   {
                      QFieldMetaData qFieldMetaData = fieldList.get(i - 1);
-                     Serializable   value          = getValue(qFieldMetaData, resultSet, i);
+                     Serializable   value          = getFieldValueFromResultSet(qFieldMetaData, resultSet, i);
                      values.put(qFieldMetaData.getName(), value);
                   }
 
@@ -187,71 +186,4 @@ public class RDBMSQueryAction extends AbstractRDBMSAction implements QueryInterf
       return (statement);
    }
 
-
-
-   /*******************************************************************************
-    **
-    *******************************************************************************/
-   private Serializable getValue(QFieldMetaData qFieldMetaData, ResultSet resultSet, int i) throws SQLException
-   {
-      switch(qFieldMetaData.getType())
-      {
-         case STRING:
-         case TEXT:
-         case HTML:
-         case PASSWORD:
-         {
-            return (QueryManager.getString(resultSet, i));
-         }
-         case INTEGER:
-         {
-            return (QueryManager.getInteger(resultSet, i));
-         }
-         case DECIMAL:
-         {
-            return (QueryManager.getBigDecimal(resultSet, i));
-         }
-         case DATE:
-         {
-            // todo - queryManager.getLocalDate?
-            return (QueryManager.getDate(resultSet, i));
-         }
-         case TIME:
-         {
-            return (QueryManager.getLocalTime(resultSet, i));
-         }
-         case DATE_TIME:
-         {
-            return (QueryManager.getInstant(resultSet, i));
-         }
-         case BOOLEAN:
-         {
-            return (QueryManager.getBoolean(resultSet, i));
-         }
-         default:
-         {
-            throw new IllegalStateException("Unexpected field type: " + qFieldMetaData.getType());
-         }
-      }
-
-   }
-
-
-
-   /*******************************************************************************
-    **
-    *******************************************************************************/
-   private String makeOrderByClause(QTableMetaData table, List<QFilterOrderBy> orderBys)
-   {
-      List<String> clauses = new ArrayList<>();
-
-      for(QFilterOrderBy orderBy : orderBys)
-      {
-         QFieldMetaData field  = table.getField(orderBy.getFieldName());
-         String         column = getColumnName(field);
-         clauses.add(column + " " + (orderBy.getIsAscending() ? "ASC" : "DESC"));
-      }
-      return (String.join(", ", clauses));
-   }
-
 }

qqq-backend-module-rdbms/src/test/java/com/kingsrook/qqq/backend/module/rdbms/TestUtils.java

@@ -26,9 +26,9 @@ import java.io.InputStream;
 import java.sql.Connection;
 import java.util.List;
 import com.kingsrook.qqq.backend.core.model.metadata.QAuthenticationType;
+import com.kingsrook.qqq.backend.core.model.metadata.QInstance;
 import com.kingsrook.qqq.backend.core.model.metadata.fields.QFieldMetaData;
 import com.kingsrook.qqq.backend.core.model.metadata.fields.QFieldType;
-import com.kingsrook.qqq.backend.core.model.metadata.QInstance;
 import com.kingsrook.qqq.backend.core.model.metadata.tables.QTableMetaData;
 import com.kingsrook.qqq.backend.core.modules.authentication.metadata.QAuthenticationMetaData;
 import com.kingsrook.qqq.backend.module.rdbms.actions.RDBMSActionTest;
@@ -131,7 +131,10 @@ public class TestUtils
          .withField(new QFieldMetaData("firstName", QFieldType.STRING).withBackendName("first_name"))
          .withField(new QFieldMetaData("lastName", QFieldType.STRING).withBackendName("last_name"))
          .withField(new QFieldMetaData("birthDate", QFieldType.DATE).withBackendName("birth_date"))
-         .withField(new QFieldMetaData("email", QFieldType.STRING))
+         .withField(new QFieldMetaData("email", QFieldType.STRING).withBackendName("email"))
+         .withField(new QFieldMetaData("isEmployed", QFieldType.BOOLEAN).withBackendName("is_employed"))
+         .withField(new QFieldMetaData("annualSalary", QFieldType.DECIMAL).withBackendName("annual_salary"))
+         .withField(new QFieldMetaData("daysWorked", QFieldType.INTEGER).withBackendName("days_worked"))
          .withBackendDetails(new RDBMSTableBackendDetails()
             .withTableName("person"));
    }

qqq-backend-module-rdbms/src/test/java/com/kingsrook/qqq/backend/module/rdbms/actions/RDBMSAggregateActionTest.java

@@ -0,0 +1,327 @@
+/*
+ * QQQ - Low-code Application Framework for Engineers.
+ * Copyright (C) 2021-2022.  Kingsrook, LLC
+ * 651 N Broad St Ste 205 # 6917 | Middletown DE 19709 | United States
+ * contact@kingsrook.com
+ * https://github.com/Kingsrook/
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU Affero General Public License as
+ * published by the Free Software Foundation, either version 3 of the
+ * License, or (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU Affero General Public License for more details.
+ *
+ * You should have received a copy of the GNU Affero General Public License
+ * along with this program.  If not, see <https://www.gnu.org/licenses/>.
+ */
+
+package com.kingsrook.qqq.backend.module.rdbms.actions;
+
+
+import java.math.BigDecimal;
+import java.util.Iterator;
+import java.util.List;
+import com.kingsrook.qqq.backend.core.actions.tables.InsertAction;
+import com.kingsrook.qqq.backend.core.exceptions.QException;
+import com.kingsrook.qqq.backend.core.model.actions.tables.aggregate.Aggregate;
+import com.kingsrook.qqq.backend.core.model.actions.tables.aggregate.AggregateInput;
+import com.kingsrook.qqq.backend.core.model.actions.tables.aggregate.AggregateOperator;
+import com.kingsrook.qqq.backend.core.model.actions.tables.aggregate.AggregateOutput;
+import com.kingsrook.qqq.backend.core.model.actions.tables.aggregate.AggregateResult;
+import com.kingsrook.qqq.backend.core.model.actions.tables.aggregate.QFilterOrderByAggregate;
+import com.kingsrook.qqq.backend.core.model.actions.tables.insert.InsertInput;
+import com.kingsrook.qqq.backend.core.model.actions.tables.query.QCriteriaOperator;
+import com.kingsrook.qqq.backend.core.model.actions.tables.query.QFilterCriteria;
+import com.kingsrook.qqq.backend.core.model.actions.tables.query.QFilterOrderBy;
+import com.kingsrook.qqq.backend.core.model.actions.tables.query.QQueryFilter;
+import com.kingsrook.qqq.backend.core.model.data.QRecord;
+import com.kingsrook.qqq.backend.core.model.session.QSession;
+import com.kingsrook.qqq.backend.module.rdbms.TestUtils;
+import org.junit.jupiter.api.Assertions;
+import org.junit.jupiter.api.BeforeEach;
+import org.junit.jupiter.api.Test;
+import static org.junit.jupiter.api.Assertions.assertTrue;
+
+
+/*******************************************************************************
+ **
+ *******************************************************************************/
+public class RDBMSAggregateActionTest extends RDBMSActionTest
+{
+
+   /*******************************************************************************
+    **
+    *******************************************************************************/
+   @BeforeEach
+   public void beforeEach() throws Exception
+   {
+      super.primeTestDatabase();
+   }
+
+
+
+   /*******************************************************************************
+    **
+    *******************************************************************************/
+   @Test
+   public void testUnfilteredNoGroupBy() throws QException
+   {
+      AggregateInput aggregateInput      = initAggregateRequest();
+      Aggregate      countOfId           = new Aggregate("id", AggregateOperator.COUNT);
+      Aggregate      sumOfId             = new Aggregate("id", AggregateOperator.SUM);
+      Aggregate      averageOfDaysWorked = new Aggregate("daysWorked", AggregateOperator.AVG);
+      Aggregate      maxAnnualSalary     = new Aggregate("annualSalary", AggregateOperator.MAX);
+      Aggregate      minFirstName        = new Aggregate("firstName", AggregateOperator.MIN);
+      aggregateInput.withAggregate(countOfId);
+      aggregateInput.withAggregate(sumOfId);
+      aggregateInput.withAggregate(averageOfDaysWorked);
+      aggregateInput.withAggregate(maxAnnualSalary);
+      aggregateInput.withAggregate(minFirstName);
+
+      AggregateOutput aggregateOutput = new RDBMSAggregateAction().execute(aggregateInput);
+
+      AggregateResult aggregateResult = aggregateOutput.getResults().get(0);
+      Assertions.assertEquals(5, aggregateResult.getAggregateValue(countOfId));
+      Assertions.assertEquals(15, aggregateResult.getAggregateValue(sumOfId));
+      Assertions.assertEquals(new BigDecimal("96.4"), aggregateResult.getAggregateValue(averageOfDaysWorked));
+      Assertions.assertEquals(new BigDecimal("1000000.00"), aggregateResult.getAggregateValue(maxAnnualSalary));
+      Assertions.assertEquals("Darin", aggregateResult.getAggregateValue(minFirstName));
+   }
+
+
+
+   /*******************************************************************************
+    **
+    *******************************************************************************/
+   @Test
+   public void testFilteredNoGroupBy() throws QException
+   {
+      AggregateInput aggregateInput      = initAggregateRequest();
+      Aggregate      countOfId           = new Aggregate("id", AggregateOperator.COUNT);
+      Aggregate      sumOfId             = new Aggregate("id", AggregateOperator.SUM);
+      Aggregate      averageOfDaysWorked = new Aggregate("daysWorked", AggregateOperator.AVG);
+      Aggregate      maxAnnualSalary     = new Aggregate("annualSalary", AggregateOperator.MAX);
+      Aggregate      minFirstName        = new Aggregate("firstName", AggregateOperator.MIN);
+      aggregateInput.withAggregate(countOfId);
+      aggregateInput.withAggregate(sumOfId);
+      aggregateInput.withAggregate(averageOfDaysWorked);
+      aggregateInput.withAggregate(maxAnnualSalary);
+      aggregateInput.withAggregate(minFirstName);
+
+      aggregateInput.setFilter(new QQueryFilter().withCriteria(new QFilterCriteria("firstName", QCriteriaOperator.IN, List.of("Tim", "James"))));
+      AggregateOutput aggregateOutput = new RDBMSAggregateAction().execute(aggregateInput);
+
+      AggregateResult aggregateResult = aggregateOutput.getResults().get(0);
+      Assertions.assertEquals(2, aggregateResult.getAggregateValue(countOfId));
+      Assertions.assertEquals(5, aggregateResult.getAggregateValue(sumOfId));
+      Assertions.assertEquals(new BigDecimal("62.0"), aggregateResult.getAggregateValue(averageOfDaysWorked));
+      Assertions.assertEquals(new BigDecimal("26000.00"), aggregateResult.getAggregateValue(maxAnnualSalary));
+      Assertions.assertEquals("James", aggregateResult.getAggregateValue(minFirstName));
+   }
+
+
+
+   /*******************************************************************************
+    **
+    *******************************************************************************/
+   @Test
+   public void testUnfilteredWithGroupBy() throws QException
+   {
+      ////////////////////////////////////////////////////
+      // insert a few extra rows from the core data set //
+      ////////////////////////////////////////////////////
+      insertExtraPersonRecords();
+
+      AggregateInput aggregateInput  = initAggregateRequest();
+      Aggregate      countOfId       = new Aggregate("id", AggregateOperator.COUNT);
+      Aggregate      sumOfDaysWorked = new Aggregate("daysWorked", AggregateOperator.SUM);
+      aggregateInput.withAggregate(countOfId);
+      aggregateInput.withAggregate(sumOfDaysWorked);
+
+      aggregateInput.withGroupByFieldName("lastName");
+      aggregateInput.setFilter(new QQueryFilter().withOrderBy(new QFilterOrderBy("lastName")));
+
+      AggregateOutput aggregateOutput = new RDBMSAggregateAction().execute(aggregateInput);
+      {
+         AggregateResult aggregateResult = aggregateOutput.getResults().get(0);
+         Assertions.assertEquals("Chamberlain", aggregateResult.getGroupByValue("lastName"));
+         Assertions.assertEquals(2, aggregateResult.getAggregateValue(countOfId));
+         Assertions.assertEquals(17, aggregateResult.getAggregateValue(sumOfDaysWorked));
+      }
+      {
+         AggregateResult aggregateResult = aggregateOutput.getResults().get(1);
+         Assertions.assertEquals("Kelkhoff", aggregateResult.getGroupByValue("lastName"));
+         Assertions.assertEquals(4, aggregateResult.getAggregateValue(countOfId));
+         Assertions.assertEquals(11364, aggregateResult.getAggregateValue(sumOfDaysWorked));
+      }
+   }
+
+
+
+   /*******************************************************************************
+    **
+    *******************************************************************************/
+   @Test
+   public void testUnfilteredWithMultiGroupBy() throws QException
+   {
+      ////////////////////////////////////////////////////
+      // insert a few extra rows from the core data set //
+      ////////////////////////////////////////////////////
+      insertExtraPersonRecords();
+
+      AggregateInput aggregateInput  = initAggregateRequest();
+      Aggregate      countOfId       = new Aggregate("id", AggregateOperator.COUNT);
+      Aggregate      sumOfDaysWorked = new Aggregate("daysWorked", AggregateOperator.SUM);
+      aggregateInput.withAggregate(countOfId);
+      aggregateInput.withAggregate(sumOfDaysWorked);
+
+      aggregateInput.withGroupByFieldName("lastName");
+      aggregateInput.withGroupByFieldName("firstName");
+
+      aggregateInput.setFilter(new QQueryFilter()
+         .withOrderBy(new QFilterOrderBy("lastName"))
+         .withOrderBy(new QFilterOrderBy("firstName")));
+
+      AggregateOutput           aggregateOutput = new RDBMSAggregateAction().execute(aggregateInput);
+      Iterator<AggregateResult> iterator        = aggregateOutput.getResults().iterator();
+      AggregateResult           aggregateResult;
+
+      aggregateResult = iterator.next();
+      Assertions.assertEquals("Chamberlain", aggregateResult.getGroupByValue("lastName"));
+      Assertions.assertEquals("Donny", aggregateResult.getGroupByValue("firstName"));
+      Assertions.assertEquals(1, aggregateResult.getAggregateValue(countOfId));
+
+      aggregateResult = iterator.next();
+      Assertions.assertEquals("Chamberlain", aggregateResult.getGroupByValue("lastName"));
+      Assertions.assertEquals("Tim", aggregateResult.getGroupByValue("firstName"));
+      Assertions.assertEquals(1, aggregateResult.getAggregateValue(countOfId));
+
+      aggregateResult = iterator.next();
+      Assertions.assertEquals("Kelkhoff", aggregateResult.getGroupByValue("lastName"));
+      Assertions.assertEquals("Aaron", aggregateResult.getGroupByValue("firstName"));
+      Assertions.assertEquals(1, aggregateResult.getAggregateValue(countOfId));
+
+      aggregateResult = iterator.next();
+      Assertions.assertEquals("Kelkhoff", aggregateResult.getGroupByValue("lastName"));
+      Assertions.assertEquals("Darin", aggregateResult.getGroupByValue("firstName"));
+      Assertions.assertEquals(2, aggregateResult.getAggregateValue(countOfId));
+
+      aggregateResult = iterator.next();
+      Assertions.assertEquals("Kelkhoff", aggregateResult.getGroupByValue("lastName"));
+      Assertions.assertEquals("Trevor", aggregateResult.getGroupByValue("firstName"));
+      Assertions.assertEquals(1, aggregateResult.getAggregateValue(countOfId));
+   }
+
+
+
+   /*******************************************************************************
+    **
+    *******************************************************************************/
+   @Test
+   public void testOrderByAggregate() throws QException
+   {
+      ////////////////////////////////////////////////////
+      // insert a few extra rows from the core data set //
+      ////////////////////////////////////////////////////
+      insertExtraPersonRecords();
+
+      AggregateInput aggregateInput  = initAggregateRequest();
+      Aggregate      countOfId       = new Aggregate("id", AggregateOperator.COUNT);
+      Aggregate      sumOfDaysWorked = new Aggregate("daysWorked", AggregateOperator.SUM);
+      aggregateInput.withAggregate(countOfId);
+      // note - don't query this value - just order by it!! aggregateInput.withAggregate(sumOfDaysWorked);
+
+      aggregateInput.withGroupByFieldName("lastName");
+
+      aggregateInput.setFilter(new QQueryFilter().withOrderBy(new QFilterOrderByAggregate(sumOfDaysWorked, false)));
+
+      AggregateOutput           aggregateOutput = new RDBMSAggregateAction().execute(aggregateInput);
+      Iterator<AggregateResult> iterator        = aggregateOutput.getResults().iterator();
+      AggregateResult           aggregateResult;
+
+      aggregateResult = iterator.next();
+      Assertions.assertEquals("Kelkhoff", aggregateResult.getGroupByValue("lastName"));
+      Assertions.assertEquals(4, aggregateResult.getAggregateValue(countOfId));
+
+      aggregateResult = iterator.next();
+      Assertions.assertEquals("Richardson", aggregateResult.getGroupByValue("lastName"));
+      Assertions.assertEquals(1, aggregateResult.getAggregateValue(countOfId));
+
+      aggregateResult = iterator.next();
+      Assertions.assertEquals("Maes", aggregateResult.getGroupByValue("lastName"));
+      Assertions.assertEquals(1, aggregateResult.getAggregateValue(countOfId));
+
+      aggregateResult = iterator.next();
+      Assertions.assertEquals("Samples", aggregateResult.getGroupByValue("lastName"));
+      Assertions.assertEquals(1, aggregateResult.getAggregateValue(countOfId));
+
+      aggregateResult = iterator.next();
+      Assertions.assertEquals("Chamberlain", aggregateResult.getGroupByValue("lastName"));
+      Assertions.assertEquals(2, aggregateResult.getAggregateValue(countOfId));
+   }
+
+
+
+   /*******************************************************************************
+    **
+    *******************************************************************************/
+   @Test
+   public void testNoRowsFound() throws QException
+   {
+      AggregateInput aggregateInput = initAggregateRequest();
+      Aggregate      countOfId      = new Aggregate("id", AggregateOperator.COUNT);
+      aggregateInput.withAggregate(countOfId);
+      aggregateInput.withFilter(new QQueryFilter(new QFilterCriteria("id", QCriteriaOperator.EQUALS, -9)));
+
+      ////////////////////////////////////////////////////////////
+      // when there's no group-by, we get a row, but w/ 0 count //
+      ////////////////////////////////////////////////////////////
+      AggregateOutput aggregateOutput = new RDBMSAggregateAction().execute(aggregateInput);
+      AggregateResult aggregateResult = aggregateOutput.getResults().get(0);
+      Assertions.assertEquals(0, aggregateResult.getAggregateValue(countOfId));
+
+      /////////////////////////////////////////////////////////////////////////////////////////
+      // but re-run w/ a group-by -- then, if no rows are found, there are 0 result objects. //
+      /////////////////////////////////////////////////////////////////////////////////////////
+      aggregateInput.withGroupByFieldName("lastName");
+      aggregateOutput = new RDBMSAggregateAction().execute(aggregateInput);
+      assertTrue(aggregateOutput.getResults().isEmpty());
+   }
+
+
+
+   /*******************************************************************************
+    **
+    *******************************************************************************/
+   private static void insertExtraPersonRecords() throws QException
+   {
+      InsertInput insertInput = new InsertInput(TestUtils.defineInstance());
+      insertInput.setSession(new QSession());
+      insertInput.setTableName(TestUtils.defineTablePerson().getName());
+      insertInput.setRecords(List.of(
+         new QRecord().withValue("lastName", "Kelkhoff").withValue("firstName", "Trevor").withValue("email", "tk@kr.com").withValue("daysWorked", 1024),
+         new QRecord().withValue("lastName", "Kelkhoff").withValue("firstName", "Darin").withValue("email", "dk2@kr.com").withValue("daysWorked", 314),
+         new QRecord().withValue("lastName", "Kelkhoff").withValue("firstName", "Aaron").withValue("email", "ak@kr.com").withValue("daysWorked", 9999),
+         new QRecord().withValue("lastName", "Chamberlain").withValue("firstName", "Donny").withValue("email", "dc@kr.com").withValue("daysWorked", 17)
+      ));
+      new InsertAction().execute(insertInput);
+   }
+
+
+
+   /*******************************************************************************
+    **
+    *******************************************************************************/
+   private AggregateInput initAggregateRequest()
+   {
+      AggregateInput aggregateInput = new AggregateInput();
+      aggregateInput.setInstance(TestUtils.defineInstance());
+      aggregateInput.setTableName(TestUtils.defineTablePerson().getName());
+      return aggregateInput;
+   }
+
+}

qqq-backend-module-rdbms/src/test/resources/prime-test-database.sql

@@ -29,14 +29,17 @@ CREATE TABLE person
    first_name VARCHAR(80) NOT NULL,
    last_name VARCHAR(80) NOT NULL,
    birth_date DATE,
-   email VARCHAR(250) NOT NULL
+   email VARCHAR(250) NOT NULL,
+   is_employed BOOLEAN,
+   annual_salary DECIMAL(12,2),
+   days_worked INTEGER
 );
 
-INSERT INTO person (id, first_name, last_name, birth_date, email) VALUES (1, 'Darin', 'Kelkhoff', '1980-05-31', 'darin.kelkhoff@gmail.com');
+INSERT INTO person (id, first_name, last_name, birth_date, email, is_employed, annual_salary, days_worked) VALUES (1, 'Darin', 'Kelkhoff', '1980-05-31', 'darin.kelkhoff@gmail.com', 1, 25000, 27);
-INSERT INTO person (id, first_name, last_name, birth_date, email) VALUES (2, 'James', 'Maes', '1980-05-15', 'jmaes@mmltholdings.com');
+INSERT INTO person (id, first_name, last_name, birth_date, email, is_employed, annual_salary, days_worked) VALUES (2, 'James', 'Maes', '1980-05-15', 'jmaes@mmltholdings.com', 1, 26000, 124);
-INSERT INTO person (id, first_name, last_name, birth_date, email) VALUES (3, 'Tim', 'Chamberlain', '1976-05-28', 'tchamberlain@mmltholdings.com');
+INSERT INTO person (id, first_name, last_name, birth_date, email, is_employed, annual_salary, days_worked) VALUES (3, 'Tim', 'Chamberlain', '1976-05-28', 'tchamberlain@mmltholdings.com', 0, null, 0);
-INSERT INTO person (id, first_name, last_name, birth_date, email) VALUES (4, 'Tyler', 'Samples', NULL, 'tsamples@mmltholdings.com');
+INSERT INTO person (id, first_name, last_name, birth_date, email, is_employed, annual_salary, days_worked) VALUES (4, 'Tyler', 'Samples', NULL, 'tsamples@mmltholdings.com', 1, 30000, 99);
-INSERT INTO person (id, first_name, last_name, birth_date, email) VALUES (5, 'Garret', 'Richardson', '1981-01-01', 'grichardson@mmltholdings.com');
+INSERT INTO person (id, first_name, last_name, birth_date, email, is_employed, annual_salary, days_worked) VALUES (5, 'Garret', 'Richardson', '1981-01-01', 'grichardson@mmltholdings.com', 1, 1000000, 232);
 
 DROP TABLE IF EXISTS carrier;
 CREATE TABLE carrier