Added check for mutated set so that the backingMap could contain all object values. The other option was to auto-refresh the instance's backing map when a getter is invoked for a valid property that isn't included in the backing map (which still may be handy/required for caching to work).

pom.xml

@@ -5,7 +5,7 @@
     <modelVersion>4.0.0</modelVersion>
     <groupId>net.helenus</groupId>
     <artifactId>helenus-core</artifactId>
-    <version>2.0.13-SNAPSHOT</version>
+    <version>2.0.14-SNAPSHOT</version>
     <packaging>jar</packaging>
 
     <name>helenus</name>

src/main/java/net/helenus/core/operation/InsertOperation.java

@@ -15,21 +15,14 @@
  */
 package net.helenus.core.operation;
 
-import java.util.*;
-
 import com.datastax.driver.core.ResultSet;
 import com.datastax.driver.core.querybuilder.BuiltStatement;
 import com.datastax.driver.core.querybuilder.Insert;
 import com.datastax.driver.core.querybuilder.QueryBuilder;
-
-import com.google.common.base.Predicates;
-import com.google.common.collect.Lists;
-import com.google.common.collect.Maps;
 import net.helenus.core.AbstractSessionOperations;
 import net.helenus.core.Getter;
 import net.helenus.core.reflect.HelenusPropertyNode;
 import net.helenus.core.reflect.MapExportable;
-import net.helenus.mapping.ColumnType;
 import net.helenus.mapping.HelenusEntity;
 import net.helenus.mapping.HelenusProperty;
 import net.helenus.mapping.MappingUtil;
@@ -37,6 +30,8 @@ import net.helenus.mapping.value.BeanColumnValueProvider;
 import net.helenus.support.Fun;
 import net.helenus.support.HelenusMappingException;
 
+import java.util.*;
+
 public final class InsertOperation extends AbstractOperation<ResultSet, InsertOperation> {
 
     private HelenusEntity entity;
@@ -59,13 +54,18 @@ public final class InsertOperation extends AbstractOperation<ResultSet, InsertOp
 
         this.entity = entity;
         this.ifNotExists = ifNotExists;
-        Set<String> keys = (pojo instanceof MapExportable) ? ((MapExportable)pojo).toMap().keySet() : null;
         Collection<HelenusProperty> properties = entity.getOrderedProperties();
+        Set<String> keys = null;
+
+        if (pojo instanceof MapExportable) {
+            keys = ((MapExportable) pojo).mutated();
+            if (keys == null) {
+                keys = ((MapExportable) pojo).toMap().keySet();
+            }
+        }
 
         for (HelenusProperty prop : properties) {
 
-            // Skip properties that are not in the map of the pojo we're storing.  This creates a path
-            // for entity instances to be {in,up}serted without including all columns in the INSERT statement.
             if (keys == null || keys.contains(prop.getPropertyName())) {
 
                 Object value = BeanColumnValueProvider.INSTANCE.getColumnValue(pojo, -1, prop);

src/main/java/net/helenus/core/reflect/MapExportable.java

@@ -16,6 +16,7 @@
 package net.helenus.core.reflect;
 
 import java.util.Map;
+import java.util.Set;
 
 public interface MapExportable {
 
@@ -23,4 +24,6 @@ public interface MapExportable {
 
 	Map<String, Object> toMap();
 
+	default Set<String> mutated() { return null; }
+
 }