Merge pull request #101 from Kingsrook/feature/CE-1402-field-case-change-behaviors

Feature/ce 1402 field case change behaviors

docs/metaData/Fields.adoc

@@ -117,3 +117,19 @@ new QTableMetaData().withName("flights").withFields(List.of(
       .withBehavior(new DateTimeDisplayValueBehavior()
          .withDefaultZoneId("UTC"))
 ----
+
+===== CaseChangeBehavior
+A field can be made to always go through a toUpperCase or toLowerCase transformation, both before it is stored in a backend,
+and after it is read from a backend, by adding a CaseChangeBehavior to it:
+
+[source,java]
+.Examples of using CaseChangeBehavior
+----
+new QTableMetaData().withName("item").withFields(List.of(
+
+   new QFieldMetaData("sku", QFieldType.STRING)
+      .withBehavior(CaseChangeBehavior.TO_UPPER_CASE)),
+
+   new QFieldMetaData("username", QFieldType.STRING)
+      .withBehavior(CaseChangeBehavior.TO_LOWER_CASE)),
+----

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

@@ -22,9 +22,12 @@
 package com.kingsrook.qqq.backend.core.actions.tables;
 
 
+import java.util.Collections;
 import com.kingsrook.qqq.backend.core.actions.ActionHelper;
 import com.kingsrook.qqq.backend.core.actions.interfaces.AggregateInterface;
 import com.kingsrook.qqq.backend.core.actions.tables.helpers.QueryStatManager;
+import com.kingsrook.qqq.backend.core.actions.values.ValueBehaviorApplier;
+import com.kingsrook.qqq.backend.core.context.QContext;
 import com.kingsrook.qqq.backend.core.exceptions.QException;
 import com.kingsrook.qqq.backend.core.logging.QLogger;
 import com.kingsrook.qqq.backend.core.model.actions.tables.aggregate.AggregateInput;
@@ -58,6 +61,11 @@ public class AggregateAction
       QTableMetaData   table   = aggregateInput.getTable();
       QBackendMetaData backend = aggregateInput.getBackend();
 
+      ////////////////////////////////////////////////////////////////////////////////////////////////////////////////////
+      // apply any available field behaviors to the filter (noting that, if anything changes, a new filter is returned) //
+      ////////////////////////////////////////////////////////////////////////////////////////////////////////////////////
+      aggregateInput.setFilter(ValueBehaviorApplier.applyFieldBehaviorsToFilter(QContext.getQInstance(), table, aggregateInput.getFilter(), Collections.emptySet()));
+
       QueryStat queryStat = QueryStatManager.newQueryStat(backend, table, aggregateInput.getFilter());
 
       QBackendModuleDispatcher qBackendModuleDispatcher = new QBackendModuleDispatcher();
@@ -67,6 +75,10 @@ public class AggregateAction
       aggregateInterface.setQueryStat(queryStat);
       AggregateOutput aggregateOutput = aggregateInterface.execute(aggregateInput);
 
+      // todo, maybe, not real important? ValueBehaviorApplier.applyFieldBehaviors(ValueBehaviorApplier.Action.READ, QContext.getQInstance(), table, aggregateOutput.getResults(), null);
+      //  issue being, the signature there... it takes a list of QRecords, which aren't what we have...
+      //  do we want to ... idk, refactor all these behavior deals?  hmm... maybe a new interface/ for ones that do reads?  not sure.
+
       QueryStatManager.getInstance().add(queryStat);
 
       return aggregateOutput;

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

@@ -22,9 +22,12 @@
 package com.kingsrook.qqq.backend.core.actions.tables;
 
 
+import java.util.Collections;
 import com.kingsrook.qqq.backend.core.actions.ActionHelper;
 import com.kingsrook.qqq.backend.core.actions.interfaces.CountInterface;
 import com.kingsrook.qqq.backend.core.actions.tables.helpers.QueryStatManager;
+import com.kingsrook.qqq.backend.core.actions.values.ValueBehaviorApplier;
+import com.kingsrook.qqq.backend.core.context.QContext;
 import com.kingsrook.qqq.backend.core.exceptions.QException;
 import com.kingsrook.qqq.backend.core.logging.QLogger;
 import com.kingsrook.qqq.backend.core.model.actions.tables.count.CountInput;
@@ -58,6 +61,11 @@ public class CountAction
       QTableMetaData   table   = countInput.getTable();
       QBackendMetaData backend = countInput.getBackend();
 
+      ////////////////////////////////////////////////////////////////////////////////////////////////////////////////////
+      // apply any available field behaviors to the filter (noting that, if anything changes, a new filter is returned) //
+      ////////////////////////////////////////////////////////////////////////////////////////////////////////////////////
+      countInput.setFilter(ValueBehaviorApplier.applyFieldBehaviorsToFilter(QContext.getQInstance(), table, countInput.getFilter(), Collections.emptySet()));
+
       QueryStat queryStat = QueryStatManager.newQueryStat(backend, table, countInput.getFilter());
 
       QBackendModuleDispatcher qBackendModuleDispatcher = new QBackendModuleDispatcher();

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

@@ -23,6 +23,8 @@ package com.kingsrook.qqq.backend.core.actions.tables;
 
 
 import java.io.Serializable;
+import java.util.ArrayList;
+import java.util.HashMap;
 import java.util.List;
 import java.util.Map;
 import java.util.Optional;
@@ -34,8 +36,10 @@ import com.kingsrook.qqq.backend.core.actions.interfaces.GetInterface;
 import com.kingsrook.qqq.backend.core.actions.tables.helpers.GetActionCacheHelper;
 import com.kingsrook.qqq.backend.core.actions.values.QPossibleValueTranslator;
 import com.kingsrook.qqq.backend.core.actions.values.QValueFormatter;
+import com.kingsrook.qqq.backend.core.actions.values.ValueBehaviorApplier;
 import com.kingsrook.qqq.backend.core.context.QContext;
 import com.kingsrook.qqq.backend.core.exceptions.QException;
+import com.kingsrook.qqq.backend.core.logging.QLogger;
 import com.kingsrook.qqq.backend.core.model.actions.tables.get.GetInput;
 import com.kingsrook.qqq.backend.core.model.actions.tables.get.GetOutput;
 import com.kingsrook.qqq.backend.core.model.actions.tables.query.QCriteriaOperator;
@@ -45,11 +49,16 @@ import com.kingsrook.qqq.backend.core.model.actions.tables.query.QueryInput;
 import com.kingsrook.qqq.backend.core.model.actions.tables.query.QueryOutput;
 import com.kingsrook.qqq.backend.core.model.data.QRecord;
 import com.kingsrook.qqq.backend.core.model.metadata.fields.AdornmentType;
+import com.kingsrook.qqq.backend.core.model.metadata.fields.FieldBehavior;
+import com.kingsrook.qqq.backend.core.model.metadata.fields.FieldFilterBehavior;
 import com.kingsrook.qqq.backend.core.model.metadata.fields.QFieldMetaData;
 import com.kingsrook.qqq.backend.core.model.metadata.tables.QTableMetaData;
 import com.kingsrook.qqq.backend.core.modules.backend.QBackendModuleDispatcher;
 import com.kingsrook.qqq.backend.core.modules.backend.QBackendModuleInterface;
+import com.kingsrook.qqq.backend.core.utils.CollectionUtils;
 import com.kingsrook.qqq.backend.core.utils.ObjectUtils;
+import com.kingsrook.qqq.backend.core.utils.Pair;
+import com.kingsrook.qqq.backend.core.utils.memoization.Memoization;
 
 
 /*******************************************************************************
@@ -58,11 +67,15 @@ import com.kingsrook.qqq.backend.core.utils.ObjectUtils;
  *******************************************************************************/
 public class GetAction
 {
+   private static final QLogger LOG = QLogger.getLogger(GetAction.class);
+
    private Optional<TableCustomizerInterface> postGetRecordCustomizer;
 
    private GetInput                 getInput;
    private QPossibleValueTranslator qPossibleValueTranslator;
 
+   private Memoization<Pair<String, String>, List<FieldFilterBehavior<?>>> getFieldFilterBehaviorMemoization = new Memoization<>();
+
 
 
    /*******************************************************************************
@@ -105,6 +118,8 @@ public class GetAction
          usingDefaultGetInterface = true;
       }
 
+      getInput = applyFieldBehaviors(getInput);
+
       getInterface.validateInput(getInput);
       getOutput = getInterface.execute(getInput);
 
@@ -130,6 +145,82 @@ public class GetAction
 
 
 
+   /*******************************************************************************
+    **
+    *******************************************************************************/
+   private GetInput applyFieldBehaviors(GetInput getInput)
+   {
+      QTableMetaData table = getInput.getTable();
+
+      try
+      {
+         if(getInput.getPrimaryKey() != null)
+         {
+            ///////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////
+            // if the input has a primary key, get its behaviors, then apply, and update the pkey in the input if the value is different //
+            ///////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////
+            List<FieldFilterBehavior<?>> fieldFilterBehaviors = getFieldFilterBehaviors(table, table.getPrimaryKeyField());
+            for(FieldFilterBehavior<?> fieldFilterBehavior : CollectionUtils.nonNullList(fieldFilterBehaviors))
+            {
+               QFilterCriteria pkeyCriteria    = new QFilterCriteria(table.getPrimaryKeyField(), QCriteriaOperator.EQUALS, getInput.getPrimaryKey());
+               QFilterCriteria updatedCriteria = ValueBehaviorApplier.apply(pkeyCriteria, QContext.getQInstance(), table, table.getField(table.getPrimaryKeyField()), fieldFilterBehavior);
+               if(updatedCriteria != pkeyCriteria)
+               {
+                  getInput.setPrimaryKey(updatedCriteria.getValues().get(0));
+               }
+            }
+         }
+         else if(getInput.getUniqueKey() != null)
+         {
+            ////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////
+            // if the input has a unique key, get its behaviors, then apply, and update the ukey values in the input if any are different //
+            ////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////
+            Map<String, Serializable> updatedUniqueKey = new HashMap<>(getInput.getUniqueKey());
+            for(String fieldName : getInput.getUniqueKey().keySet())
+            {
+               List<FieldFilterBehavior<?>> fieldFilterBehaviors = getFieldFilterBehaviors(table, fieldName);
+               for(FieldFilterBehavior<?> fieldFilterBehavior : CollectionUtils.nonNullList(fieldFilterBehaviors))
+               {
+                  QFilterCriteria ukeyCriteria    = new QFilterCriteria(fieldName, QCriteriaOperator.EQUALS, updatedUniqueKey.get(fieldName));
+                  QFilterCriteria updatedCriteria = ValueBehaviorApplier.apply(ukeyCriteria, QContext.getQInstance(), table, table.getField(table.getPrimaryKeyField()), fieldFilterBehavior);
+                  updatedUniqueKey.put(fieldName, updatedCriteria.getValues().get(0));
+               }
+            }
+            getInput.setUniqueKey(updatedUniqueKey);
+         }
+      }
+      catch(Exception e)
+      {
+         LOG.warn("Error applying field behaviors to get input - will run with original inputs", e);
+      }
+
+      return (getInput);
+   }
+
+
+
+   /*******************************************************************************
+    **
+    *******************************************************************************/
+   private List<FieldFilterBehavior<?>> getFieldFilterBehaviors(QTableMetaData tableMetaData, String fieldName)
+   {
+      Pair<String, String> key = new Pair<>(tableMetaData.getName(), fieldName);
+      return getFieldFilterBehaviorMemoization.getResult(key, (p) ->
+      {
+         List<FieldFilterBehavior<?>> rs = new ArrayList<>();
+         for(FieldBehavior<?> fieldBehavior : CollectionUtils.nonNullCollection(tableMetaData.getFields().get(fieldName).getBehaviors()))
+         {
+            if(fieldBehavior instanceof FieldFilterBehavior<?> fieldFilterBehavior)
+            {
+               rs.add(fieldFilterBehavior);
+            }
+         }
+         return (rs);
+      }).orElse(null);
+   }
+
+
+
    /*******************************************************************************
     ** shorthand way to call for the most common use-case, when you just want the
     ** output record to be returned.
@@ -255,6 +346,8 @@ public class GetAction
          returnRecord = postGetRecordCustomizer.get().postQuery(getInput, List.of(record)).get(0);
       }
 
+      ValueBehaviorApplier.applyFieldBehaviors(ValueBehaviorApplier.Action.READ, QContext.getQInstance(), getInput.getTable(), List.of(record), null);
+
       if(getInput.getShouldTranslatePossibleValues())
       {
          if(qPossibleValueTranslator == null)

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

@@ -25,6 +25,7 @@ package com.kingsrook.qqq.backend.core.actions.tables;
 import java.io.Serializable;
 import java.util.ArrayList;
 import java.util.Collection;
+import java.util.Collections;
 import java.util.HashSet;
 import java.util.List;
 import java.util.Map;
@@ -41,6 +42,7 @@ import com.kingsrook.qqq.backend.core.actions.tables.helpers.QueryActionCacheHel
 import com.kingsrook.qqq.backend.core.actions.tables.helpers.QueryStatManager;
 import com.kingsrook.qqq.backend.core.actions.values.QPossibleValueTranslator;
 import com.kingsrook.qqq.backend.core.actions.values.QValueFormatter;
+import com.kingsrook.qqq.backend.core.actions.values.ValueBehaviorApplier;
 import com.kingsrook.qqq.backend.core.context.QContext;
 import com.kingsrook.qqq.backend.core.exceptions.QException;
 import com.kingsrook.qqq.backend.core.logging.QLogger;
@@ -117,6 +119,11 @@ public class QueryAction
          }
       }
 
+      ////////////////////////////////////////////////////////////////////////////////////////////////////////////////////
+      // apply any available field behaviors to the filter (noting that, if anything changes, a new filter is returned) //
+      ////////////////////////////////////////////////////////////////////////////////////////////////////////////////////
+      queryInput.setFilter(ValueBehaviorApplier.applyFieldBehaviorsToFilter(QContext.getQInstance(), table, queryInput.getFilter(), Collections.emptySet()));
+
       QueryStat queryStat = QueryStatManager.newQueryStat(backend, table, queryInput.getFilter());
 
       QBackendModuleDispatcher qBackendModuleDispatcher = new QBackendModuleDispatcher();
@@ -284,6 +291,8 @@ public class QueryAction
          records = postQueryRecordCustomizer.get().postQuery(queryInput, records);
       }
 
+      ValueBehaviorApplier.applyFieldBehaviors(ValueBehaviorApplier.Action.READ, QContext.getQInstance(), queryInput.getTable(), records, null);
+
       if(queryInput.getShouldTranslatePossibleValues())
       {
          if(qPossibleValueTranslator == null)

qqq-backend-core/src/main/java/com/kingsrook/qqq/backend/core/actions/values/ValueBehaviorApplier.java

@@ -22,12 +22,18 @@
 package com.kingsrook.qqq.backend.core.actions.values;
 
 
+import java.io.Serializable;
+import java.util.ArrayList;
 import java.util.List;
+import java.util.Objects;
 import java.util.Set;
+import com.kingsrook.qqq.backend.core.model.actions.tables.query.QFilterCriteria;
+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.QInstance;
 import com.kingsrook.qqq.backend.core.model.metadata.fields.FieldBehavior;
 import com.kingsrook.qqq.backend.core.model.metadata.fields.FieldDisplayBehavior;
+import com.kingsrook.qqq.backend.core.model.metadata.fields.FieldFilterBehavior;
 import com.kingsrook.qqq.backend.core.model.metadata.fields.QFieldMetaData;
 import com.kingsrook.qqq.backend.core.model.metadata.tables.QTableMetaData;
 import com.kingsrook.qqq.backend.core.utils.CollectionUtils;
@@ -46,6 +52,7 @@ public class ValueBehaviorApplier
    {
       INSERT,
       UPDATE,
+      READ,
       FORMATTING
    }
 
@@ -97,4 +104,169 @@ public class ValueBehaviorApplier
       }
    }
 
+
+
+   /*******************************************************************************
+    ** apply field behaviors (of FieldFilterBehavior type) to a QQueryFilter.
+    ** note that, we don't like to ever edit a QQueryFilter itself (e.g., as it might
+    ** have come from meta-data, or it might have some immutable structures in it).
+    ** So, if any changes are needed, they'll be returned in a clone.
+    ** So, either way, you should use this method like:
+    *
+    ** QQueryFilter myFilter = // wherever I got my filter from
+    ** myFilter = ValueBehaviorApplier.applyFieldBehaviorsToFilter(QContext.getInstance, table, myFilter, null);
+    ** // e.g., always re-assign over top of your filter.
+    *******************************************************************************/
+   public static QQueryFilter applyFieldBehaviorsToFilter(QInstance instance, QTableMetaData table, QQueryFilter filter, Set<FieldBehavior<?>> behaviorsToOmit)
+   {
+      ////////////////////////////////////////////////
+      // for null or empty filter, return the input //
+      ////////////////////////////////////////////////
+      if(filter == null || !filter.hasAnyCriteria())
+      {
+         return (filter);
+      }
+
+      ///////////////////////////////////////////////////////////////////
+      // track if we need to make & return a clone.                    //
+      // which will be the case if we get back any different criteria, //
+      // or any different sub-filters, than what we originally had.    //
+      ///////////////////////////////////////////////////////////////////
+      boolean needToUseClone = false;
+
+      ///////////////////////////////////////////////////////////////////////////////////////////////////////////////////
+      // make a new criteria list, and a new subFilter list - either null, if the source was null, or a new array list //
+      ///////////////////////////////////////////////////////////////////////////////////////////////////////////////////
+      List<QFilterCriteria> newCriteriaList = filter.getCriteria() == null ? null : new ArrayList<>();
+      List<QQueryFilter>    newSubFilters   = filter.getSubFilters() == null ? null : new ArrayList<>();
+
+      //////////////////////////////////////////////////////////////////////////////
+      // for each criteria, if its field has any applicable behaviors, apply them //
+      //////////////////////////////////////////////////////////////////////////////
+      for(QFilterCriteria criteria : CollectionUtils.nonNullList(filter.getCriteria()))
+      {
+         QFieldMetaData field = table.getFields().get(criteria.getFieldName());
+         if(field == null && criteria.getFieldName() != null && criteria.getFieldName().contains("."))
+         {
+            String[] parts = criteria.getFieldName().split("\\.");
+            if(parts.length == 2)
+            {
+               QTableMetaData joinTable = instance.getTable(parts[0]);
+               if(joinTable != null)
+               {
+                  field = joinTable.getFields().get(parts[1]);
+               }
+            }
+         }
+
+         QFilterCriteria criteriaToUse = criteria;
+         if(field != null)
+         {
+            for(FieldBehavior<?> fieldBehavior : CollectionUtils.nonNullCollection(field.getBehaviors()))
+            {
+               boolean applyBehavior = true;
+               if(behaviorsToOmit != null && behaviorsToOmit.contains(fieldBehavior))
+               {
+                  applyBehavior = false;
+               }
+
+               if(applyBehavior && fieldBehavior instanceof FieldFilterBehavior<?> filterBehavior)
+               {
+                  //////////////////////////////////////////////////////////////////////
+                  // call to apply the behavior on the criteria - which will return a //
+                  // new criteria if any values are changed, else the input criteria  //
+                  //////////////////////////////////////////////////////////////////////
+                  criteriaToUse = apply(criteriaToUse, instance, table, field, filterBehavior);
+
+                  ////////////////////////////////////////////////////////////////////////////////////////////////////////////
+                  // if the new criteria is not the same as the old criteria, mark that we need to make and return a clone. //
+                  ////////////////////////////////////////////////////////////////////////////////////////////////////////////
+                  if(criteriaToUse != criteria)
+                  {
+                     needToUseClone = true;
+                  }
+               }
+            }
+         }
+
+         newCriteriaList.add(criteriaToUse);
+      }
+
+      /////////////////////////////////////////////////////////////////////////////////////////////////
+      // similar to above - iterate over the subfilters, making a recursive call, and tracking if we //
+      // got back the same object (in which case, there are no changes, and we don't need to clone), //
+      // or a different object (in which case, we do need a clone, because there were changes).      //
+      /////////////////////////////////////////////////////////////////////////////////////////////////
+      for(QQueryFilter subFilter : CollectionUtils.nonNullList(filter.getSubFilters()))
+      {
+         QQueryFilter newSubFilter = applyFieldBehaviorsToFilter(instance, table, subFilter, behaviorsToOmit);
+         if(newSubFilter != subFilter)
+         {
+            newSubFilters.add(newSubFilter);
+            needToUseClone = true;
+         }
+         else
+         {
+            newSubFilters.add(subFilter);
+         }
+      }
+
+      //////////////////////////////////////////////////////////////////////////////////////////////////
+      // if we need to return a clone, then do so, replacing the lists with the ones we built in here //
+      //////////////////////////////////////////////////////////////////////////////////////////////////
+      if(needToUseClone)
+      {
+         QQueryFilter cloneFilter = filter.clone();
+         cloneFilter.setCriteria(newCriteriaList);
+         cloneFilter.setSubFilters(newSubFilters);
+         return (cloneFilter);
+      }
+
+      /////////////////////////////////////////////////////////////////////////////
+      // else, if no clone needed (e.g., no changes), return the original filter //
+      /////////////////////////////////////////////////////////////////////////////
+      return (filter);
+   }
+
+
+
+   /*******************************************************************************
+    **
+    *******************************************************************************/
+   public static QFilterCriteria apply(QFilterCriteria criteria, QInstance instance, QTableMetaData table, QFieldMetaData field, FieldFilterBehavior<?> filterBehavior)
+   {
+      if(criteria == null || CollectionUtils.nullSafeIsEmpty(criteria.getValues()))
+      {
+         return (criteria);
+      }
+
+      List<Serializable> newValues  = new ArrayList<>();
+      boolean            changedAny = false;
+
+      for(Serializable value : criteria.getValues())
+      {
+         Serializable newValue = filterBehavior.applyToFilterCriteriaValue(value, instance, table, field);
+         if(!Objects.equals(value, newValue))
+         {
+            newValues.add(newValue);
+            changedAny = true;
+         }
+         else
+         {
+            newValues.add(value);
+         }
+      }
+
+      if(changedAny)
+      {
+         QFilterCriteria clone = criteria.clone();
+         clone.setValues(newValues);
+         return (clone);
+      }
+      else
+      {
+         return (criteria);
+      }
+   }
+
 }

qqq-backend-core/src/main/java/com/kingsrook/qqq/backend/core/model/metadata/fields/CaseChangeBehavior.java

@@ -0,0 +1,172 @@
+/*
+ * QQQ - Low-code Application Framework for Engineers.
+ * Copyright (C) 2021-2024.  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.metadata.fields;
+
+
+import java.io.Serializable;
+import java.util.ArrayList;
+import java.util.Collections;
+import java.util.List;
+import java.util.Objects;
+import java.util.function.Function;
+import com.kingsrook.qqq.backend.core.actions.values.ValueBehaviorApplier;
+import com.kingsrook.qqq.backend.core.model.data.QRecord;
+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.utils.CollectionUtils;
+
+
+/*******************************************************************************
+ ** Field behavior that changes the case of string values.
+ *******************************************************************************/
+public enum CaseChangeBehavior implements FieldBehavior<CaseChangeBehavior>, FieldBehaviorForFrontend, FieldFilterBehavior<CaseChangeBehavior>
+{
+   NONE(null),
+   TO_UPPER_CASE((String s) -> s.toUpperCase()),
+   TO_LOWER_CASE((String s) -> s.toLowerCase());
+
+
+   private final Function<String, String> function;
+
+
+
+   /*******************************************************************************
+    **
+    *******************************************************************************/
+   CaseChangeBehavior(Function<String, String> function)
+   {
+      this.function = function;
+   }
+
+
+
+   /*******************************************************************************
+    **
+    *******************************************************************************/
+   @Override
+   public CaseChangeBehavior getDefault()
+   {
+      return (NONE);
+   }
+
+
+
+   /*******************************************************************************
+    **
+    *******************************************************************************/
+   @Override
+   public void apply(ValueBehaviorApplier.Action action, List<QRecord> recordList, QInstance instance, QTableMetaData table, QFieldMetaData field)
+   {
+      if(this.equals(NONE))
+      {
+         return;
+      }
+
+      switch(this)
+      {
+         case TO_UPPER_CASE, TO_LOWER_CASE -> applyFunction(recordList, table, field);
+         default -> throw new IllegalStateException("Unexpected enum value: " + this);
+      }
+   }
+
+
+
+   /*******************************************************************************
+    **
+    *******************************************************************************/
+   private void applyFunction(List<QRecord> recordList, QTableMetaData table, QFieldMetaData field)
+   {
+      String fieldName = field.getName();
+      for(QRecord record : CollectionUtils.nonNullList(recordList))
+      {
+         String value = record.getValueString(fieldName);
+         if(value != null && function != null)
+         {
+            record.setValue(fieldName, function.apply(value));
+         }
+      }
+   }
+
+
+
+   /*******************************************************************************
+    **
+    *******************************************************************************/
+   @Override
+   public Serializable applyToFilterCriteriaValue(Serializable value, QInstance instance, QTableMetaData table, QFieldMetaData field)
+   {
+      if(this.equals(NONE) || function == null)
+      {
+         return (value);
+      }
+
+      if(value instanceof String s)
+      {
+         String newValue = function.apply(s);
+         if(!Objects.equals(value, newValue))
+         {
+            return (newValue);
+         }
+      }
+
+      return (value);
+   }
+
+
+
+   /*******************************************************************************
+    **
+    *******************************************************************************/
+   @Override
+   public boolean allowMultipleBehaviorsOfThisType()
+   {
+      return (false);
+   }
+
+
+
+   /*******************************************************************************
+    **
+    *******************************************************************************/
+   @Override
+   public List<String> validateBehaviorConfiguration(QTableMetaData tableMetaData, QFieldMetaData fieldMetaData)
+   {
+      if(this == NONE)
+      {
+         return Collections.emptyList();
+      }
+
+      List<String> errors      = new ArrayList<>();
+      String       errorSuffix = " field [" + fieldMetaData.getName() + "] in table [" + tableMetaData.getName() + "]";
+
+      if(fieldMetaData.getType() != null)
+      {
+         if(!fieldMetaData.getType().isStringLike())
+         {
+            errors.add("A CaseChange was a applied to a non-String-like field:" + errorSuffix);
+         }
+      }
+
+      return (errors);
+   }
+
+}

qqq-backend-core/src/main/java/com/kingsrook/qqq/backend/core/model/metadata/fields/FieldBehaviorForFrontend.java

@@ -0,0 +1,34 @@
+/*
+ * QQQ - Low-code Application Framework for Engineers.
+ * Copyright (C) 2021-2024.  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.metadata.fields;
+
+
+import java.io.Serializable;
+
+
+/*******************************************************************************
+ ** Marker interface for a field behavior which you might want to send to a
+ ** frontend (e.g., so it can edit values to match what'll happen in the backend).
+ *******************************************************************************/
+public interface FieldBehaviorForFrontend extends Serializable
+{
+}

qqq-backend-core/src/main/java/com/kingsrook/qqq/backend/core/model/metadata/fields/FieldDisplayBehavior.java

@@ -23,7 +23,8 @@ package com.kingsrook.qqq.backend.core.model.metadata.fields;
 
 
 /*******************************************************************************
- **
+ ** Interface to mark a field behavior as one to be used during generating
+ ** display values.
  *******************************************************************************/
 public interface FieldDisplayBehavior<T extends FieldDisplayBehavior<T>> extends FieldBehavior<T>
 {

qqq-backend-core/src/main/java/com/kingsrook/qqq/backend/core/model/metadata/fields/FieldFilterBehavior.java

@@ -0,0 +1,43 @@
+/*
+ * QQQ - Low-code Application Framework for Engineers.
+ * Copyright (C) 2021-2024.  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.metadata.fields;
+
+
+import java.io.Serializable;
+import com.kingsrook.qqq.backend.core.model.metadata.QInstance;
+import com.kingsrook.qqq.backend.core.model.metadata.tables.QTableMetaData;
+
+
+/*******************************************************************************
+ ** Interface to mark a field behavior as one to be used before a query filter
+ ** is executed.
+ *******************************************************************************/
+public interface FieldFilterBehavior<T extends FieldFilterBehavior<T>> extends FieldBehavior<T>
+{
+
+   /*******************************************************************************
+    ** Apply the filter to a value from a criteria.
+    ** If you don't want to change the input value, return the parameter.
+    *******************************************************************************/
+   Serializable applyToFilterCriteriaValue(Serializable value, QInstance instance, QTableMetaData table, QFieldMetaData field);
+
+}

qqq-backend-core/src/main/java/com/kingsrook/qqq/backend/core/model/metadata/frontend/QFrontendFieldMetaData.java

@@ -23,13 +23,17 @@ package com.kingsrook.qqq.backend.core.model.metadata.frontend;
 
 
 import java.io.Serializable;
+import java.util.ArrayList;
 import java.util.List;
 import com.fasterxml.jackson.annotation.JsonInclude;
 import com.fasterxml.jackson.annotation.JsonInclude.Include;
 import com.kingsrook.qqq.backend.core.model.metadata.fields.FieldAdornment;
+import com.kingsrook.qqq.backend.core.model.metadata.fields.FieldBehavior;
+import com.kingsrook.qqq.backend.core.model.metadata.fields.FieldBehaviorForFrontend;
 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.help.QHelpContent;
+import com.kingsrook.qqq.backend.core.utils.CollectionUtils;
 
 
 /*******************************************************************************
@@ -53,6 +57,8 @@ public class QFrontendFieldMetaData
    private List<FieldAdornment> adornments;
    private List<QHelpContent>   helpContents;
 
+   private List<FieldBehaviorForFrontend> behaviors;
+
    //////////////////////////////////////////////////////////////////////////////////
    // do not add setters.  take values from the source-object in the constructor!! //
    //////////////////////////////////////////////////////////////////////////////////
@@ -75,6 +81,18 @@ public class QFrontendFieldMetaData
       this.adornments = fieldMetaData.getAdornments();
       this.defaultValue = fieldMetaData.getDefaultValue();
       this.helpContents = fieldMetaData.getHelpContents();
+
+      for(FieldBehavior<?> behavior : CollectionUtils.nonNullCollection(fieldMetaData.getBehaviors()))
+      {
+         if(behavior instanceof FieldBehaviorForFrontend fbff)
+         {
+            if(behaviors == null)
+            {
+               behaviors = new ArrayList<>();
+            }
+            behaviors.add(fbff);
+         }
+      }
    }
 
 
@@ -198,4 +216,14 @@ public class QFrontendFieldMetaData
       return helpContents;
    }
 
+
+
+   /*******************************************************************************
+    ** Getter for fieldBehaviors
+    **
+    *******************************************************************************/
+   public List<FieldBehaviorForFrontend> getBehaviors()
+   {
+      return behaviors;
+   }
 }

qqq-backend-core/src/test/java/com/kingsrook/qqq/backend/core/actions/tables/GetActionTest.java

@@ -22,15 +22,28 @@
 package com.kingsrook.qqq.backend.core.actions.tables;
 
 
+import java.util.List;
+import java.util.Map;
+import java.util.Set;
 import com.kingsrook.qqq.backend.core.BaseTest;
+import com.kingsrook.qqq.backend.core.context.QContext;
 import com.kingsrook.qqq.backend.core.exceptions.QException;
 import com.kingsrook.qqq.backend.core.model.actions.tables.get.GetInput;
 import com.kingsrook.qqq.backend.core.model.actions.tables.get.GetOutput;
+import com.kingsrook.qqq.backend.core.model.actions.tables.insert.InsertInput;
+import com.kingsrook.qqq.backend.core.model.data.QRecord;
+import com.kingsrook.qqq.backend.core.model.metadata.QInstance;
+import com.kingsrook.qqq.backend.core.model.metadata.fields.CaseChangeBehavior;
+import com.kingsrook.qqq.backend.core.model.metadata.fields.QFieldMetaData;
+import com.kingsrook.qqq.backend.core.model.metadata.tables.QTableMetaData;
+import com.kingsrook.qqq.backend.core.model.metadata.tables.UniqueKey;
 import com.kingsrook.qqq.backend.core.modules.backend.implementations.memory.MemoryRecordStore;
+import com.kingsrook.qqq.backend.core.utils.TestUtils;
 import org.junit.jupiter.api.AfterEach;
 import org.junit.jupiter.api.BeforeEach;
 import org.junit.jupiter.api.Test;
 import static org.junit.jupiter.api.Assertions.assertNotNull;
+import static org.junit.jupiter.api.Assertions.assertNull;
 
 
 /*******************************************************************************
@@ -71,4 +84,40 @@ class GetActionTest extends BaseTest
       assertNotNull(result.getRecord());
    }
 
+
+
+   /*******************************************************************************
+    **
+    *******************************************************************************/
+   @Test
+   void testFilterFieldBehaviors() throws QException
+   {
+      /////////////////////////////////////////////////////////////////////////
+      // insert one shape with a mixed-case name, one with an all-lower name //
+      /////////////////////////////////////////////////////////////////////////
+      new InsertAction().execute(new InsertInput(TestUtils.TABLE_NAME_SHAPE).withRecords(List.of(
+         new QRecord().withValue("name", "Triangle"),
+         new QRecord().withValue("name", "square")
+      )));
+
+      ///////////////////////////////////////////////////////////////////////////
+      // now set the shape table's name field to have a to-lower-case behavior //
+      ///////////////////////////////////////////////////////////////////////////
+      QInstance      qInstance = QContext.getQInstance();
+      QTableMetaData table     = qInstance.getTable(TestUtils.TABLE_NAME_SHAPE);
+      table.withUniqueKey(new UniqueKey("name"));
+      QFieldMetaData field = table.getField("name");
+      field.setBehaviors(Set.of(CaseChangeBehavior.TO_LOWER_CASE));
+
+      ///////////////////////////////////////////////////////////////////////////////////////////////////////////////
+      // confirm that if we query for "Triangle", we can't find it (because query will to-lower-case the criteria) //
+      ///////////////////////////////////////////////////////////////////////////////////////////////////////////////
+      assertNull(GetAction.execute(TestUtils.TABLE_NAME_SHAPE, Map.of("name", "Triangle")));
+
+      //////////////////////////////////////////////////////////////////////////////////////////////////////////
+      // confirm that if we query for "SQUARE", we do find it (because query will to-lower-case the criteria) //
+      //////////////////////////////////////////////////////////////////////////////////////////////////////////
+      assertNotNull(GetAction.execute(TestUtils.TABLE_NAME_SHAPE, Map.of("name", "sQuArE")));
+   }
+
 }

qqq-backend-core/src/test/java/com/kingsrook/qqq/backend/core/actions/tables/QueryActionTest.java

@@ -25,6 +25,7 @@ package com.kingsrook.qqq.backend.core.actions.tables;
 import java.io.Serializable;
 import java.util.ArrayList;
 import java.util.List;
+import java.util.Set;
 import com.kingsrook.qqq.backend.core.BaseTest;
 import com.kingsrook.qqq.backend.core.actions.async.AsyncRecordPipeLoop;
 import com.kingsrook.qqq.backend.core.actions.reporting.RecordPipe;
@@ -32,13 +33,18 @@ import com.kingsrook.qqq.backend.core.actions.tables.helpers.QueryStatManager;
 import com.kingsrook.qqq.backend.core.context.QContext;
 import com.kingsrook.qqq.backend.core.exceptions.QException;
 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.actions.tables.query.QueryInput;
 import com.kingsrook.qqq.backend.core.model.actions.tables.query.QueryOutput;
 import com.kingsrook.qqq.backend.core.model.data.QRecord;
 import com.kingsrook.qqq.backend.core.model.metadata.QInstance;
+import com.kingsrook.qqq.backend.core.model.metadata.fields.CaseChangeBehavior;
+import com.kingsrook.qqq.backend.core.model.metadata.fields.QFieldMetaData;
 import com.kingsrook.qqq.backend.core.model.metadata.tables.Capability;
+import com.kingsrook.qqq.backend.core.model.metadata.tables.QTableMetaData;
 import com.kingsrook.qqq.backend.core.model.querystats.QueryStat;
 import com.kingsrook.qqq.backend.core.model.querystats.QueryStatMetaDataProvider;
 import com.kingsrook.qqq.backend.core.model.session.QSession;
@@ -499,4 +505,40 @@ class QueryActionTest extends BaseTest
       insertInput.setRecords(recordList);
       new InsertAction().execute(insertInput);
    }
+
+
+
+   /*******************************************************************************
+    **
+    *******************************************************************************/
+   @Test
+   void testFilterFieldBehaviors() throws QException
+   {
+      /////////////////////////////////////////////////////////////////////////
+      // insert one shape with a mixed-case name, one with an all-lower name //
+      /////////////////////////////////////////////////////////////////////////
+      new InsertAction().execute(new InsertInput(TestUtils.TABLE_NAME_SHAPE).withRecords(List.of(
+         new QRecord().withValue("name", "Triangle"),
+         new QRecord().withValue("name", "square")
+      )));
+
+      ///////////////////////////////////////////////////////////////////////////
+      // now set the shape table's name field to have a to-lower-case behavior //
+      ///////////////////////////////////////////////////////////////////////////
+      QInstance      qInstance = QContext.getQInstance();
+      QTableMetaData table     = qInstance.getTable(TestUtils.TABLE_NAME_SHAPE);
+      QFieldMetaData field     = table.getField("name");
+      field.setBehaviors(Set.of(CaseChangeBehavior.TO_LOWER_CASE));
+
+      ///////////////////////////////////////////////////////////////////////////////////////////////////////////////
+      // confirm that if we query for "Triangle", we can't find it (because query will to-lower-case the criteria) //
+      ///////////////////////////////////////////////////////////////////////////////////////////////////////////////
+      assertEquals(0, QueryAction.execute(TestUtils.TABLE_NAME_SHAPE, new QQueryFilter(new QFilterCriteria("name", QCriteriaOperator.EQUALS, "Triangle"))).size());
+
+      //////////////////////////////////////////////////////////////////////////////////////////////////////////
+      // confirm that if we query for "SQUARE", we do find it (because query will to-lower-case the criteria) //
+      //////////////////////////////////////////////////////////////////////////////////////////////////////////
+      assertEquals(1, QueryAction.execute(TestUtils.TABLE_NAME_SHAPE, new QQueryFilter(new QFilterCriteria("name", QCriteriaOperator.EQUALS, "SqUaRe"))).size());
+   }
+
 }

qqq-backend-core/src/test/java/com/kingsrook/qqq/backend/core/actions/values/ValueBehaviorApplierTest.java

@@ -22,16 +22,22 @@
 package com.kingsrook.qqq.backend.core.actions.values;
 
 
+import java.io.Serializable;
 import java.util.List;
 import java.util.Optional;
 import java.util.Set;
 import com.kingsrook.qqq.backend.core.BaseTest;
 import com.kingsrook.qqq.backend.core.context.QContext;
+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.QQueryFilter;
 import com.kingsrook.qqq.backend.core.model.data.QRecord;
 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.CaseChangeBehavior;
 import com.kingsrook.qqq.backend.core.model.metadata.fields.FieldBehavior;
 import com.kingsrook.qqq.backend.core.model.metadata.fields.FieldDisplayBehavior;
+import com.kingsrook.qqq.backend.core.model.metadata.fields.FieldFilterBehavior;
+import com.kingsrook.qqq.backend.core.model.metadata.fields.QFieldMetaData;
 import com.kingsrook.qqq.backend.core.model.metadata.fields.ValueTooLongBehavior;
 import com.kingsrook.qqq.backend.core.model.metadata.tables.QTableMetaData;
 import com.kingsrook.qqq.backend.core.utils.CollectionUtils;
@@ -39,7 +45,9 @@ import com.kingsrook.qqq.backend.core.utils.TestUtils;
 import org.junit.jupiter.api.Test;
 import static org.junit.jupiter.api.Assertions.assertEquals;
 import static org.junit.jupiter.api.Assertions.assertFalse;
+import static org.junit.jupiter.api.Assertions.assertNotSame;
 import static org.junit.jupiter.api.Assertions.assertNull;
+import static org.junit.jupiter.api.Assertions.assertSame;
 import static org.junit.jupiter.api.Assertions.assertTrue;
 import static org.junit.jupiter.api.Assertions.fail;
 
@@ -255,4 +263,140 @@ class ValueBehaviorApplierTest extends BaseTest
          }
       }
    }
+
+
+
+   /*******************************************************************************
+    **
+    *******************************************************************************/
+   @Test
+   void testFilters()
+   {
+      QInstance      qInstance = QContext.getQInstance();
+      QTableMetaData table     = qInstance.getTable(TestUtils.TABLE_NAME_SHAPE);
+      QFieldMetaData field     = table.getField("name");
+      field.setBehaviors(Set.of(CaseChangeBehavior.TO_LOWER_CASE));
+
+      assertNull(ValueBehaviorApplier.applyFieldBehaviorsToFilter(qInstance, table, null, null));
+
+      QQueryFilter emptyFilter = new QQueryFilter();
+      assertSame(emptyFilter, ValueBehaviorApplier.applyFieldBehaviorsToFilter(qInstance, table, emptyFilter, null));
+
+      QQueryFilter hasCriteriaButNotUpdated = new QQueryFilter().withCriteria(new QFilterCriteria("id", QCriteriaOperator.EQUALS, 1));
+      assertSame(hasCriteriaButNotUpdated, ValueBehaviorApplier.applyFieldBehaviorsToFilter(qInstance, table, hasCriteriaButNotUpdated, null));
+
+      QQueryFilter hasSubFiltersButNotUpdated = new QQueryFilter().withSubFilters(List.of(new QQueryFilter().withCriteria(new QFilterCriteria("id", QCriteriaOperator.EQUALS, 1))));
+      assertSame(hasSubFiltersButNotUpdated, ValueBehaviorApplier.applyFieldBehaviorsToFilter(qInstance, table, hasSubFiltersButNotUpdated, null));
+
+      QQueryFilter hasCriteriaWithoutValues = new QQueryFilter().withSubFilters(List.of(new QQueryFilter().withCriteria(new QFilterCriteria("name", QCriteriaOperator.EQUALS))));
+      assertSame(hasCriteriaWithoutValues, ValueBehaviorApplier.applyFieldBehaviorsToFilter(qInstance, table, hasCriteriaWithoutValues, null));
+
+      QQueryFilter hasCriteriaAndSubFiltersButNotUpdated = new QQueryFilter()
+         .withCriteria(new QFilterCriteria("id", QCriteriaOperator.EQUALS, 1))
+         .withSubFilters(List.of(new QQueryFilter().withCriteria(new QFilterCriteria("id", QCriteriaOperator.EQUALS, 1))));
+      assertSame(hasCriteriaAndSubFiltersButNotUpdated, ValueBehaviorApplier.applyFieldBehaviorsToFilter(qInstance, table, hasCriteriaAndSubFiltersButNotUpdated, null));
+
+      QQueryFilter hasCriteriaToUpdate = new QQueryFilter().withCriteria(new QFilterCriteria("name", QCriteriaOperator.EQUALS, "Triangle"));
+      QQueryFilter hasCriteriaUpdated  = ValueBehaviorApplier.applyFieldBehaviorsToFilter(qInstance, table, hasCriteriaToUpdate, null);
+      assertNotSame(hasCriteriaToUpdate, hasCriteriaUpdated);
+      assertEquals("triangle", hasCriteriaUpdated.getCriteria().get(0).getValues().get(0));
+      assertEquals(hasCriteriaToUpdate.getSubFilters(), hasCriteriaUpdated.getSubFilters());
+
+      QQueryFilter hasSubFilterToUpdate = new QQueryFilter().withSubFilter(new QQueryFilter().withCriteria(new QFilterCriteria("name", QCriteriaOperator.EQUALS, "Oval")));
+      QQueryFilter hasSubFilterUpdated  = ValueBehaviorApplier.applyFieldBehaviorsToFilter(qInstance, table, hasSubFilterToUpdate, null);
+      assertNotSame(hasSubFilterToUpdate, hasSubFilterUpdated);
+      assertEquals("oval", hasSubFilterUpdated.getSubFilters().get(0).getCriteria().get(0).getValues().get(0));
+      assertEquals(hasSubFilterToUpdate.getCriteria(), hasSubFilterUpdated.getCriteria());
+
+      QQueryFilter hasCriteriaAndSubFilterToUpdate = new QQueryFilter()
+         .withCriteria(new QFilterCriteria("name", QCriteriaOperator.EQUALS, "Square"))
+         .withSubFilter(new QQueryFilter().withCriteria(new QFilterCriteria("name", QCriteriaOperator.EQUALS, "Circle")));
+      QQueryFilter hasCriteriaAndSubFilterUpdated = ValueBehaviorApplier.applyFieldBehaviorsToFilter(qInstance, table, hasCriteriaAndSubFilterToUpdate, null);
+      assertNotSame(hasCriteriaAndSubFilterToUpdate, hasCriteriaAndSubFilterUpdated);
+      assertEquals("square", hasCriteriaAndSubFilterUpdated.getCriteria().get(0).getValues().get(0));
+      assertEquals("circle", hasCriteriaAndSubFilterUpdated.getSubFilters().get(0).getCriteria().get(0).getValues().get(0));
+
+      QQueryFilter hasMultiValueCriteriaToUpdate = new QQueryFilter().withCriteria(new QFilterCriteria("name", QCriteriaOperator.IN, "Triangle", "Square"));
+      QQueryFilter hasMultiValueCriteriaUpdated  = ValueBehaviorApplier.applyFieldBehaviorsToFilter(qInstance, table, hasMultiValueCriteriaToUpdate, null);
+      assertNotSame(hasMultiValueCriteriaToUpdate, hasMultiValueCriteriaUpdated);
+      assertEquals(List.of("triangle", "square"), hasMultiValueCriteriaUpdated.getCriteria().get(0).getValues());
+      assertEquals(hasMultiValueCriteriaToUpdate.getSubFilters(), hasMultiValueCriteriaUpdated.getSubFilters());
+
+      QQueryFilter hasMultipleCriteriaOnlyToUpdate = new QQueryFilter()
+         .withCriteria(new QFilterCriteria("name", QCriteriaOperator.EQUALS, "Square"))
+         .withCriteria(new QFilterCriteria("id", QCriteriaOperator.IS_NOT_BLANK));
+
+      QQueryFilter hasMultipleCriteriaOnlyOneUpdated = ValueBehaviorApplier.applyFieldBehaviorsToFilter(qInstance, table, hasMultipleCriteriaOnlyToUpdate, null);
+      assertNotSame(hasMultipleCriteriaOnlyToUpdate, hasMultipleCriteriaOnlyOneUpdated);
+      assertEquals(2, hasMultipleCriteriaOnlyOneUpdated.getCriteria().size());
+      assertEquals(List.of("square"), hasMultipleCriteriaOnlyOneUpdated.getCriteria().get(0).getValues());
+      assertEquals(hasMultipleCriteriaOnlyToUpdate.getSubFilters(), hasMultipleCriteriaOnlyOneUpdated.getSubFilters());
+
+      //////////////////////////////////////////////////////////
+      // set 2 behaviors on the field - make sure both happen //
+      //////////////////////////////////////////////////////////
+      field.setBehaviors(Set.of(CaseChangeBehavior.TO_LOWER_CASE, new AppendSomethingBehavior("-x")));
+      QQueryFilter criteriaValueToUpdateTwice = new QQueryFilter().withCriteria(new QFilterCriteria("name", QCriteriaOperator.EQUALS, "Triangle"));
+      QQueryFilter criteriaValueUpdatedTwice  = ValueBehaviorApplier.applyFieldBehaviorsToFilter(qInstance, table, criteriaValueToUpdateTwice, null);
+      assertNotSame(criteriaValueToUpdateTwice, criteriaValueUpdatedTwice);
+      assertEquals("triangle-x", criteriaValueUpdatedTwice.getCriteria().get(0).getValues().get(0));
+      assertEquals(criteriaValueToUpdateTwice.getSubFilters(), criteriaValueUpdatedTwice.getSubFilters());
+   }
+
+
+
+   /***************************************************************************
+    *
+    ***************************************************************************/
+   public static class AppendSomethingBehavior implements FieldBehavior<AppendSomethingBehavior>, FieldFilterBehavior<AppendSomethingBehavior>
+   {
+      private String something;
+
+
+
+      /*******************************************************************************
+       ** Constructor
+       **
+       *******************************************************************************/
+      public AppendSomethingBehavior(String something)
+      {
+         this.something = something;
+      }
+
+
+
+      /***************************************************************************
+       *
+       ***************************************************************************/
+      @Override
+      public Serializable applyToFilterCriteriaValue(Serializable value, QInstance instance, QTableMetaData table, QFieldMetaData field)
+      {
+         return value + something;
+      }
+
+
+
+      /***************************************************************************
+       *
+       ***************************************************************************/
+      @Override
+      public AppendSomethingBehavior getDefault()
+      {
+         return null;
+      }
+
+
+
+      /***************************************************************************
+       *
+       ***************************************************************************/
+      @Override
+      public void apply(ValueBehaviorApplier.Action action, List<QRecord> recordList, QInstance instance, QTableMetaData table, QFieldMetaData field)
+      {
+         //////////
+         // noop //
+         //////////
+      }
+   }
+
 }

qqq-backend-core/src/test/java/com/kingsrook/qqq/backend/core/model/metadata/fields/CaseChangeBehaviorTest.java

@@ -0,0 +1,242 @@
+/*
+ * QQQ - Low-code Application Framework for Engineers.
+ * Copyright (C) 2021-2024.  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.metadata.fields;
+
+
+import java.util.Collections;
+import java.util.List;
+import java.util.Set;
+import java.util.stream.Collectors;
+import com.kingsrook.qqq.backend.core.BaseTest;
+import com.kingsrook.qqq.backend.core.actions.tables.GetAction;
+import com.kingsrook.qqq.backend.core.actions.tables.InsertAction;
+import com.kingsrook.qqq.backend.core.actions.tables.QueryAction;
+import com.kingsrook.qqq.backend.core.actions.tables.UpdateAction;
+import com.kingsrook.qqq.backend.core.actions.values.ValueBehaviorApplier;
+import com.kingsrook.qqq.backend.core.context.QContext;
+import com.kingsrook.qqq.backend.core.exceptions.QException;
+import com.kingsrook.qqq.backend.core.model.actions.tables.insert.InsertInput;
+import com.kingsrook.qqq.backend.core.model.actions.tables.update.UpdateInput;
+import com.kingsrook.qqq.backend.core.model.data.QRecord;
+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.utils.TestUtils;
+import com.kingsrook.qqq.backend.core.utils.collections.ListBuilder;
+import org.junit.jupiter.api.Test;
+import static org.junit.jupiter.api.Assertions.assertEquals;
+import static org.junit.jupiter.api.Assertions.assertNull;
+import static org.junit.jupiter.api.Assertions.assertTrue;
+
+
+/*******************************************************************************
+ ** Unit test for CaseChangeBehavior 
+ *******************************************************************************/
+class CaseChangeBehaviorTest extends BaseTest
+{
+   public static final String FIELD = "firstName" ;
+
+
+
+   /*******************************************************************************
+    **
+    *******************************************************************************/
+   @Test
+   void testNone()
+   {
+      assertNull(applyToRecord(CaseChangeBehavior.NONE, new QRecord(), ValueBehaviorApplier.Action.INSERT).getValue(FIELD));
+      assertNull(applyToRecord(CaseChangeBehavior.NONE, new QRecord().withValue(FIELD, null), ValueBehaviorApplier.Action.INSERT).getValue(FIELD));
+      assertEquals("John", applyToRecord(CaseChangeBehavior.NONE, new QRecord().withValue(FIELD, "John"), ValueBehaviorApplier.Action.INSERT).getValue(FIELD));
+
+      assertEquals(ListBuilder.of("John", null, "Jane"), applyToRecords(CaseChangeBehavior.NONE, List.of(
+            new QRecord().withValue(FIELD, "John"),
+            new QRecord(),
+            new QRecord().withValue(FIELD, "Jane")),
+         ValueBehaviorApplier.Action.INSERT).stream().map(r -> r.getValueString(FIELD)).toList());
+   }
+
+
+
+   /*******************************************************************************
+    **
+    *******************************************************************************/
+   @Test
+   void testToUpperCase()
+   {
+      assertNull(applyToRecord(CaseChangeBehavior.TO_UPPER_CASE, new QRecord(), ValueBehaviorApplier.Action.INSERT).getValue(FIELD));
+      assertNull(applyToRecord(CaseChangeBehavior.TO_UPPER_CASE, new QRecord().withValue(FIELD, null), ValueBehaviorApplier.Action.INSERT).getValue(FIELD));
+      assertEquals("JOHN", applyToRecord(CaseChangeBehavior.TO_UPPER_CASE, new QRecord().withValue(FIELD, "John"), ValueBehaviorApplier.Action.INSERT).getValue(FIELD));
+
+      assertEquals(ListBuilder.of("JOHN", null, "JANE"), applyToRecords(CaseChangeBehavior.TO_UPPER_CASE, List.of(
+            new QRecord().withValue(FIELD, "John"),
+            new QRecord(),
+            new QRecord().withValue(FIELD, "Jane")),
+         ValueBehaviorApplier.Action.INSERT).stream().map(r -> r.getValueString(FIELD)).toList());
+   }
+
+
+
+   /*******************************************************************************
+    **
+    *******************************************************************************/
+   @Test
+   void testToLowerCase()
+   {
+      assertNull(applyToRecord(CaseChangeBehavior.TO_LOWER_CASE, new QRecord(), ValueBehaviorApplier.Action.INSERT).getValue(FIELD));
+      assertNull(applyToRecord(CaseChangeBehavior.TO_LOWER_CASE, new QRecord().withValue(FIELD, null), ValueBehaviorApplier.Action.INSERT).getValue(FIELD));
+      assertEquals("john", applyToRecord(CaseChangeBehavior.TO_LOWER_CASE, new QRecord().withValue(FIELD, "John"), ValueBehaviorApplier.Action.INSERT).getValue(FIELD));
+
+      assertEquals(ListBuilder.of("john", null, "jane"), applyToRecords(CaseChangeBehavior.TO_LOWER_CASE, List.of(
+            new QRecord().withValue(FIELD, "John"),
+            new QRecord(),
+            new QRecord().withValue(FIELD, "Jane")),
+         ValueBehaviorApplier.Action.INSERT).stream().map(r -> r.getValueString(FIELD)).toList());
+   }
+
+
+
+   /*******************************************************************************
+    **
+    *******************************************************************************/
+   private QRecord applyToRecord(CaseChangeBehavior behavior, QRecord record, ValueBehaviorApplier.Action action)
+   {
+      return (applyToRecords(behavior, List.of(record), action).get(0));
+   }
+
+
+
+   /*******************************************************************************
+    **
+    *******************************************************************************/
+   private List<QRecord> applyToRecords(CaseChangeBehavior behavior, List<QRecord> records, ValueBehaviorApplier.Action action)
+   {
+      QTableMetaData table = QContext.getQInstance().getTable(TestUtils.TABLE_NAME_PERSON_MEMORY);
+      behavior.apply(action, records, QContext.getQInstance(), table, table.getField(FIELD));
+      return (records);
+   }
+
+
+
+   /*******************************************************************************
+    **
+    *******************************************************************************/
+   @Test
+   void testReads() throws QException
+   {
+      TestUtils.insertDefaultShapes(QContext.getQInstance());
+
+      List<QRecord> records = QueryAction.execute(TestUtils.TABLE_NAME_SHAPE, null);
+      assertEquals(Set.of("Triangle", "Square", "Circle"), records.stream().map(r -> r.getValueString("name")).collect(Collectors.toSet()));
+
+      QFieldMetaData field = QContext.getQInstance().getTable(TestUtils.TABLE_NAME_SHAPE).getField("name");
+      field.setBehaviors(Set.of(CaseChangeBehavior.TO_UPPER_CASE));
+
+      records = QueryAction.execute(TestUtils.TABLE_NAME_SHAPE, null);
+      assertEquals(Set.of("TRIANGLE", "SQUARE", "CIRCLE"), records.stream().map(r -> r.getValueString("name")).collect(Collectors.toSet()));
+
+      field.setBehaviors(Set.of(CaseChangeBehavior.TO_LOWER_CASE));
+      assertEquals("triangle", GetAction.execute(TestUtils.TABLE_NAME_SHAPE, 1).getValueString("name"));
+
+      field.setBehaviors(Set.of(CaseChangeBehavior.NONE));
+      assertEquals("Triangle", GetAction.execute(TestUtils.TABLE_NAME_SHAPE, 1).getValueString("name"));
+   }
+
+
+
+   /*******************************************************************************
+    **
+    *******************************************************************************/
+   @Test
+   void testWrites() throws QException
+   {
+      Integer id = 100;
+
+      QFieldMetaData field = QContext.getQInstance().getTable(TestUtils.TABLE_NAME_SHAPE).getField("name");
+      field.setBehaviors(Set.of(CaseChangeBehavior.TO_UPPER_CASE));
+      new InsertAction().execute(new InsertInput(TestUtils.TABLE_NAME_SHAPE).withRecord(new QRecord().withValue("id", id).withValue("name", "Octagon")));
+
+      //////////////////////////////////////////////////////////////////////////////////
+      // turn off the to-upper-case behavior, so we'll see what was actually inserted //
+      //////////////////////////////////////////////////////////////////////////////////
+      field.setBehaviors(Collections.emptySet());
+      assertEquals("OCTAGON", GetAction.execute(TestUtils.TABLE_NAME_SHAPE, id).getValueString("name"));
+
+      ////////////////////////////////////////////
+      // change to toLowerCase and do an update //
+      ////////////////////////////////////////////
+      field.setBehaviors(Set.of(CaseChangeBehavior.TO_LOWER_CASE));
+      new UpdateAction().execute(new UpdateInput(TestUtils.TABLE_NAME_SHAPE).withRecord(new QRecord().withValue("id", id).withValue("name", "Octagon")));
+
+      ////////////////////////////////////////////////////////////////////////////////////
+      // turn off the to-lower-case behavior, so we'll see what was actually udpated to //
+      ////////////////////////////////////////////////////////////////////////////////////
+      field.setBehaviors(Collections.emptySet());
+      assertEquals("octagon", GetAction.execute(TestUtils.TABLE_NAME_SHAPE, id).getValueString("name"));
+   }
+
+
+
+   /*******************************************************************************
+    **
+    *******************************************************************************/
+   @Test
+   void testFilter()
+   {
+      QInstance      qInstance = QContext.getQInstance();
+      QTableMetaData table     = qInstance.getTable(TestUtils.TABLE_NAME_SHAPE);
+      QFieldMetaData field     = table.getField("name");
+      field.setBehaviors(Set.of(CaseChangeBehavior.TO_UPPER_CASE));
+      assertEquals("SQUARE", CaseChangeBehavior.TO_UPPER_CASE.applyToFilterCriteriaValue("square", qInstance, table, field));
+
+      field.setBehaviors(Set.of(CaseChangeBehavior.TO_LOWER_CASE));
+      assertEquals("triangle", CaseChangeBehavior.TO_LOWER_CASE.applyToFilterCriteriaValue("Triangle", qInstance, table, field));
+
+      field.setBehaviors(Set.of(CaseChangeBehavior.NONE));
+      assertEquals("Circle", CaseChangeBehavior.NONE.applyToFilterCriteriaValue("Circle", qInstance, table, field));
+   }
+
+
+
+   /*******************************************************************************
+    **
+    *******************************************************************************/
+   @Test
+   void testValidation()
+   {
+      QTableMetaData table = QContext.getQInstance().getTable(TestUtils.TABLE_NAME_SHAPE);
+
+      ///////////////////////////////////////////
+      // should be no errors on a string field //
+      ///////////////////////////////////////////
+      assertTrue(CaseChangeBehavior.TO_UPPER_CASE.validateBehaviorConfiguration(table, table.getField("name")).isEmpty());
+
+      //////////////////////////////////////////
+      // should be an error on a number field //
+      //////////////////////////////////////////
+      assertEquals(1, CaseChangeBehavior.TO_LOWER_CASE.validateBehaviorConfiguration(table, table.getField("id")).size());
+
+      /////////////////////////////////////////
+      // NONE should be allowed on any field //
+      /////////////////////////////////////////
+      assertTrue(CaseChangeBehavior.NONE.validateBehaviorConfiguration(table, table.getField("id")).isEmpty());
+   }
+
+}