can now specify which attributes to return for query and scan

README.md

@@ -39,11 +39,11 @@ region=dynamodb.eu-west-1.amazonaws.com
 
     (scan client "events")
 
-    (scan client  "events" [["author" "eq" "steen"]])
+    (scan client  "events" [["author" "eq" "steen"]] nil)
 
     (find-items client "events" "NORMAL" true)   
 
-    (find-items client "events" "NORMAL" true ["between" 715 815])
+    (find-items client "events" "NORMAL" true ["between" 715 815] [attr1 attr2])
 
 Return values have meta data containing consumed units, count and lastkey where applicable.
 

src/dynamo4clj/core.clj

@@ -154,25 +154,27 @@
      (= operator "null") (doto (Condition.) (.withComparisonOperator ComparisonOperator/NULL) (.withAttributeValueList ^java.util.List (vector (to-attr-value param1))))
      (= operator "in") (doto (Condition.) (.withComparisonOperator ComparisonOperator/IN) (.withAttributeValueList ^java.util.List (vector (to-attr-value param1)))))))
 
-(defn find-items [^AmazonDynamoDBClient client table key consistent & range]
-  "Find items with key and optional range. Range has the form [operator param1 param2] or [operator param1]"
-  (let [condition (create-condition (first range))       
-        req (cond
-             (empty? range) (doto (QueryRequest.) (.withTableName table) (.withHashKeyValue (to-attr-value key)) (.withConsistentRead consistent))
-             (not (empty? range)) (doto (QueryRequest.) (.withTableName table) (.withHashKeyValue (to-attr-value key)) (.withRangeKeyCondition condition) (.withConsistentRead consistent)))]
+(defn find-items [^AmazonDynamoDBClient client table key consistent & [range-condition return-attributes]]
+  "Find items with key and optional range. Range has the form [operator param1 param2] or [operator param1], and return-attributes is a vector of attributes to return as in [attr1 attr2]"
+  (let [condition (create-condition range-condition)       
+        reqq (cond
+             (empty? range-condition) (doto (QueryRequest.) (.withTableName table) (.withHashKeyValue (to-attr-value key)) (.withConsistentRead consistent))
+             (not (empty? range-condition)) (doto (QueryRequest.) (.withTableName table) (.withHashKeyValue (to-attr-value key)) (.withRangeKeyCondition condition) (.withConsistentRead consistent)))
+        req (if (empty? return-attributes) reqq (doto reqq (.withAttributesToGet (map #(name %) return-attributes))))]
     (let [qres (. client (query req))]
       (with-meta (keywordize-keys (map to-map (.getItems qres)))
         {:consumed-capacity-units (.getConsumedCapacityUnits qres) :count (.getCount qres) :last-key (.getLastEvaluatedKey qres)}))))
 
-(defn scan [^AmazonDynamoDBClient client table & conditions]
-  "Return the items in a DynamoDB table. Conditions is vector of tuples like [field operator param1 param2] or [field operator param1]"
+(defn scan [^AmazonDynamoDBClient client table & [conditions return-attributes]]
+  "Return the items in a DynamoDB table. Conditions is vector of tuples like [field operator param1 param2] or [field operator param1]. Return-attributes is a vector of attributes to return as in [attr1 attr2]"
   (let [conds (loop [c (first conditions) res {}]
                 (if (empty? c)
                   res
                   (recur (rest c) (assoc res (first (first c)) (create-condition (vec (rest (first c))))))))]
-    (let [req (cond
+    (let [reqq (cond
                 (empty? conds) (doto (ScanRequest.) (.withTableName table))
-                (not (empty? conds)) (doto (ScanRequest.) (.withTableName table) (.withScanFilter conds)))]
+                (not (empty? conds)) (doto (ScanRequest.) (.withTableName table) (.withScanFilter conds)))
+          req (if (empty? return-attributes) reqq (doto reqq (.withAttributesToGet (map #(name %) return-attributes))))]
       (let [sres (. client (scan req))]
         (with-meta (keywordize-keys (map to-map (.getItems sres)))
           {:consumed-capacity-units (.getConsumedCapacityUnits sres) :count (.getCount sres) :last-key (.getLastEvaluatedKey sres)})))))