diff --git a/qqq-backend-module-rdbms/src/main/java/com/kingsrook/qqq/backend/module/rdbms/jdbc/ConnectionManager.java b/qqq-backend-module-rdbms/src/main/java/com/kingsrook/qqq/backend/module/rdbms/jdbc/ConnectionManager.java
index 5ec62e34..0aa7d18d 100644
--- a/qqq-backend-module-rdbms/src/main/java/com/kingsrook/qqq/backend/module/rdbms/jdbc/ConnectionManager.java
+++ b/qqq-backend-module-rdbms/src/main/java/com/kingsrook/qqq/backend/module/rdbms/jdbc/ConnectionManager.java
@@ -178,7 +178,18 @@ public class ConnectionManager
          case RDBMSBackendMetaData.VENDOR_AURORA_MYSQL -> "jdbc:mysql://" + backend.getHostName() + ":" + backend.getPort() + "/" + backend.getDatabaseName() + "?rewriteBatchedStatements=true&zeroDateTimeBehavior=convertToNull&useSSL=false";
          case RDBMSBackendMetaData.VENDOR_MYSQL -> "jdbc:mysql://" + backend.getHostName() + ":" + backend.getPort() + "/" + backend.getDatabaseName() + "?rewriteBatchedStatements=true&zeroDateTimeBehavior=convertToNull";
          case RDBMSBackendMetaData.VENDOR_H2 -> "jdbc:h2:" + backend.getHostName() + ":" + backend.getDatabaseName() + ";MODE=MySQL;DB_CLOSE_DELAY=-1";
-         default -> throw new IllegalArgumentException("Unsupported rdbms backend vendor: " + backend.getVendor());
+         default ->
+         {
+            String connectionString = backend.buildConnectionString();
+            if(connectionString == null)
+            {
+               throw new IllegalArgumentException("Unsupported rdbms backend vendor: " + backend.getVendor() + " (and null returned by backendMetaData.buildConnectionString())");
+            }
+            else
+            {
+               yield (connectionString);
+            }
+         }
       };
    }
 
diff --git a/qqq-backend-module-rdbms/src/main/java/com/kingsrook/qqq/backend/module/rdbms/model/metadata/RDBMSBackendMetaData.java b/qqq-backend-module-rdbms/src/main/java/com/kingsrook/qqq/backend/module/rdbms/model/metadata/RDBMSBackendMetaData.java
index b5b623b6..28d7dc7a 100644
--- a/qqq-backend-module-rdbms/src/main/java/com/kingsrook/qqq/backend/module/rdbms/model/metadata/RDBMSBackendMetaData.java
+++ b/qqq-backend-module-rdbms/src/main/java/com/kingsrook/qqq/backend/module/rdbms/model/metadata/RDBMSBackendMetaData.java
@@ -456,6 +456,16 @@ public class RDBMSBackendMetaData extends QBackendMetaData
       return (this);
    }
 
+
+
+   /***************************************************************************
+    **
+    ***************************************************************************/
+   public String buildConnectionString()
+   {
+      return null;
+   }
+
    /*******************************************************************************
     ** Getter for queriesForNewConnections
     *******************************************************************************/