Added Version.createVersion(byte[]) to create Version from query results

Author: gmfeinberg

CHANGELOG.md

@@ -10,6 +10,9 @@ query in an iterable/iterator format. The returned QueryIterableResult should
 be used in a try-with-resources statement to ensure proper closing of
 resources.
 - updated NoSQLHandle and QueryRequest interfaces to extend AutoClosable
+- added Version.createVersion(byte[]) to allow creation of a Version object from a
+query that returns row_version() as a BinaryValue. The Version can be used for
+conditional put and delete operations
 - added support for setting an extension to the User Agent http header by 
 setting the ExtensionUserAgent property on NoSQLHandlerConfig.
 

driver/src/main/java/oracle/nosql/driver/Version.java

@@ -37,7 +37,10 @@ public byte[] getBytes() {
     }
 
     /**
-     * @hidden
+     * Creates a Version instance from a byte[] which may have been acquired
+     * from a query using the row_version() function which returns a FieldValue
+     * of type BINARY.
+     *
      * @param version the version to use
      * @return a new Version instance
      */

driver/src/test/java/oracle/nosql/driver/BasicTest.java

@@ -797,6 +797,27 @@ public void testPutGetDelete() {
                        (serialVersion > 2), /* modtime should be recent */
                        recordKB);
 
+        /* save this for comparison below */
+        Version version = getRes.getVersion();
+
+        /*
+         * get the row version of the same row using a query and assert
+         * that the versions are the same. A test could be created to use this
+         * in a condition put/delete operation but that functionality is already
+         * tested. This just ensures that the versions acquired from get()
+         * and from row_version are identical
+         */
+        try (QueryRequest queryReq = new QueryRequest()) {
+            final String versionQuery = "select row_version($t) as version " +
+                "from " + tableName + " $t where id = 10";
+            queryReq.setStatement(versionQuery);
+            QueryResult queryRet = handle.query(queryReq);
+            MapValue result = queryRet.getResults().get(0);
+            Version qVersion = Version.createVersion(
+                result.get("version").asBinary().getValue());
+            assertArrayEquals(version.getBytes(), qVersion.getBytes());
+        }
+
         /* Get a row with ABSOLUTE consistency */
         getReq.setConsistency(Consistency.ABSOLUTE);
         getRes = handle.get(getReq);