Support update expressions in single request update

Author: anasatirbasa

services-custom/dynamodb-enhanced/src/main/java/software/amazon/awssdk/enhanced/dynamodb/internal/update/UpdateExpressionResolver.java

@@ -22,6 +22,7 @@
 import static software.amazon.awssdk.utils.CollectionUtils.filterMap;
 
 import java.util.Arrays;
+import java.util.Collection;
 import java.util.Collections;
 import java.util.HashMap;
 import java.util.List;
@@ -88,7 +89,7 @@ public UpdateExpression resolve() {
                      .orElse(null);
     }
 
-    private static Set<String> attributesPresentInOtherExpressions(List<UpdateExpression> updateExpressions) {
+    private static Set<String> attributesPresentInOtherExpressions(Collection<UpdateExpression> updateExpressions) {
         return updateExpressions.stream()
                                 .filter(Objects::nonNull)
                                 .map(UpdateExpressionConverter::findAttributeNames)
@@ -106,7 +107,7 @@ public static UpdateExpression generateItemSetExpression(Map<String, AttributeVa
     }
 
     public static UpdateExpression generateItemRemoveExpression(Map<String, AttributeValue> itemMap,
-                                                                Set<String> nonRemoveAttributes) {
+                                                                Collection<String> nonRemoveAttributes) {
         Map<String, AttributeValue> removeAttributes =
             filterMap(itemMap, e -> isNullAttributeValue(e.getValue()) && !nonRemoveAttributes.contains(e.getKey()));
 

services-custom/dynamodb-enhanced/src/main/java/software/amazon/awssdk/enhanced/dynamodb/model/TransactUpdateItemEnhancedRequest.java

@@ -22,10 +22,6 @@
 import software.amazon.awssdk.enhanced.dynamodb.DynamoDbEnhancedAsyncClient;
 import software.amazon.awssdk.enhanced.dynamodb.DynamoDbEnhancedClient;
 import software.amazon.awssdk.enhanced.dynamodb.Expression;
-import software.amazon.awssdk.enhanced.dynamodb.update.AddAction;
-import software.amazon.awssdk.enhanced.dynamodb.update.DeleteAction;
-import software.amazon.awssdk.enhanced.dynamodb.update.RemoveAction;
-import software.amazon.awssdk.enhanced.dynamodb.update.SetAction;
 import software.amazon.awssdk.enhanced.dynamodb.update.UpdateExpression;
 import software.amazon.awssdk.services.dynamodb.model.ReturnValuesOnConditionCheckFailure;
 
@@ -247,19 +243,23 @@ public Builder<T> item(T item) {
         }
 
         /**
-         * Specifies custom update operations using DynamoDB's native update expression syntax. Enables advanced modifications
-         * like incrementing counters or modifying lists/sets.
-         * <p><b>Precedence:</b> Request expressions (highest) > Extension expressions > Item attributes (lowest).
-         * This method overrides any conflicting operations from item attributes or extensions.
-         * <p><b>Backward compatible:</b> New feature that doesn't affect existing behavior when not used.
+         * Specifies custom update operations using DynamoDB's native update expression syntax.
+         * <p>
+         * <b>Precedence:</b> When performing an update, the final set of attribute modifications is determined as follows:
+         * <ol>
+         *   <li><b>Request-level UpdateExpression</b> (set via this method) has the highest priority and overrides any
+         *   conflicting updates from extensions or POJO item attributes.</li>
+         *   <li><b>Extension-provided UpdateExpression</b> (if present) has medium priority and overrides conflicting updates
+         *   from POJO item attributes.</li>
+         *   <li><b>POJO item attributes</b> have the lowest priority; any conflicts with extension or request expressions are
+         *   overridden.</li>
+         * </ol>
+         * If the same attribute is updated by multiple sources, only the action from the highest-priority source is applied.
+         * <p>
+         * This method does not affect existing behavior if not used.
          *
          * @param updateExpression the update operations to perform
          * @return a builder of this type
-         * @see UpdateExpression
-         * @see SetAction
-         * @see AddAction
-         * @see RemoveAction
-         * @see DeleteAction
          */
         public Builder<T> updateExpression(UpdateExpression updateExpression) {
             this.updateExpression = updateExpression;

services-custom/dynamodb-enhanced/src/main/java/software/amazon/awssdk/enhanced/dynamodb/model/UpdateItemEnhancedRequest.java

@@ -24,10 +24,6 @@
 import software.amazon.awssdk.enhanced.dynamodb.DynamoDbAsyncTable;
 import software.amazon.awssdk.enhanced.dynamodb.DynamoDbTable;
 import software.amazon.awssdk.enhanced.dynamodb.Expression;
-import software.amazon.awssdk.enhanced.dynamodb.update.AddAction;
-import software.amazon.awssdk.enhanced.dynamodb.update.DeleteAction;
-import software.amazon.awssdk.enhanced.dynamodb.update.RemoveAction;
-import software.amazon.awssdk.enhanced.dynamodb.update.SetAction;
 import software.amazon.awssdk.enhanced.dynamodb.update.UpdateExpression;
 import software.amazon.awssdk.services.dynamodb.model.DeleteItemRequest;
 import software.amazon.awssdk.services.dynamodb.model.PutItemRequest;
@@ -332,21 +328,23 @@ public Builder<T> item(T item) {
         }
 
         /**
-         * Specifies custom update operations using DynamoDB's native update expression syntax. Enables advanced modifications
-         * like incrementing counters or modifying lists/sets.
+         * Specifies custom update operations using DynamoDB's native update expression syntax.
          * <p>
-         * <b>Precedence:</b> Request expressions (highest) > Extension expressions > Item attributes (lowest).
-         * This method overrides any conflicting operations from item attributes or extensions.
+         * <b>Precedence:</b> When performing an update, the final set of attribute modifications is determined as follows:
+         * <ol>
+         *   <li><b>Request-level UpdateExpression</b> (set via this method) has the highest priority and overrides any
+         *   conflicting updates from extensions or POJO item attributes.</li>
+         *   <li><b>Extension-provided UpdateExpression</b> (if present) has medium priority and overrides conflicting updates
+         *   from POJO item attributes.</li>
+         *   <li><b>POJO item attributes</b> have the lowest priority; any conflicts with extension or request expressions are
+         *   overridden.</li>
+         * </ol>
+         * If the same attribute is updated by multiple sources, only the action from the highest-priority source is applied.
          * <p>
-         * <b>Backward compatible:</b> New feature that doesn't affect existing behavior when not used.
+         * This method does not affect existing behavior if not used.
          *
          * @param updateExpression the update operations to perform
          * @return a builder of this type
-         * @see UpdateExpression
-         * @see SetAction
-         * @see AddAction
-         * @see RemoveAction
-         * @see DeleteAction
          */
         public Builder<T> updateExpression(UpdateExpression updateExpression) {
             this.updateExpression = updateExpression;