Dynamodb query error - Query key condition not supported

Question

I am trying to query my dynamodb table to get feed_guid and status_id = 1. But it returns Query key condition not supported error. Please find my table schema and query.

$result =$dynamodbClient->createTable(array(
            'TableName' => 'feed',
            'AttributeDefinitions' => array(
                array('AttributeName' => 'user_id', 'AttributeType' => 'S'),
                array('AttributeName' => 'feed_guid',    'AttributeType' => 'S'),
                array('AttributeName' => 'status_id',  'AttributeType' => 'N'),
            ),
            'KeySchema' => array(
                array('AttributeName' => 'feed_guid', 'KeyType' => 'HASH'),
            ),

            'GlobalSecondaryIndexes' => array(
                array(
                    'IndexName' => 'StatusIndex',
                    'ProvisionedThroughput' => array (
                        'ReadCapacityUnits' => 5,
                        'WriteCapacityUnits' => 5
                    ),
                    'KeySchema' => array(
                        array(
                            'AttributeName' => 'status_id',
                            'KeyType' => 'HASH'
                        ),
                    ),
                    'Projection' => array(
                        'ProjectionType' => 'ALL'
                    )
                ),

                array(
                    'IndexName' => 'UserIdIndex',
                    'ProvisionedThroughput' => array (
                        'ReadCapacityUnits' => 5,
                        'WriteCapacityUnits' => 5
                    ),
                    'KeySchema' => array(
                        array(
                            'AttributeName' => 'user_id',
                            'KeyType' => 'HASH'
                        ),
                    ),
                    'Projection' => array(
                        'ProjectionType' => 'ALL'
                    )
                )

            ),
            'ProvisionedThroughput' => array(
                'ReadCapacityUnits'  => 10,
                'WriteCapacityUnits' => 20
            )
        ));

Following is my query to update that table.

 $result = $dynamodbClient->query(array(
            'TableName' => 'feed',
            'KeyConditionExpression' => 'feed_guid = :v_fid AND status_id = :v_sid ',
            'ExpressionAttributeValues' =>  array(
                ':v_fid' => array('S' => '71a27f0547cd5456d9ee7c181b6cb2f8'),
                ':v_sid' => array('N' => 1)
            ),
            'ConsistentRead' => false
        ));

Strand

you haven't define status_id as range to execute this query – Translate

So we can't user secondary indexes only? – Strand

Answer 1

As mentioned, the attribute included in "KeyConditionExpression" should be your hash key only, matching your base table schema (in this case 'feed_guid'). If you want to query on both 'feed_guid' and 'status_id', you need to create the table with hash and range key and specify 'status_id' as your range key.

Global secondary indexes are completely separate from the base table, so in this case you can query the indexes separately (use 'status_id' in key condition when querying StatusIndex and use 'user_id' in key condition when querying UserIdIndex).

Please find more details on querying global secondary indexes here

Evaluate

Also noteworthy that the hash key condition needs to be an equality : =; so you may get this error if you try to use >=, <, begins_with etc in the hash-based condition of your key condition expression. – Procurance

Answer 2

Another option would be to use a FilterExpression in addition to the KeyConditionExpression. As Daniela mentioned KeyConditionExpression should contain only columns in the hash key. But any un-indexed columns can be included in the FilterExpression.

Mohammedanism

FilterExpression achieves absolutely nothing. Don't use it to solve your problems. – Velarium

Answer 3

You need to have both hash_key (Partition Key) and range_key (Sort Key) provided in the KeyConditionExpression. hash_key must be exact match (=), but the range_key can use other operators like 'begins_with'

Mook