public int count ( Class < ? > clazz , DynamoDBQueryExpression queryExpression , DynamoDBMapperConfig config ) { config = mergeConfig ( config ) ; QueryRequest queryRequest = createQueryRequestFromExpression ( clazz , queryExpression , config ) ; queryRequest . setCount ( true ) ; // Count queries can also be truncated for large datasets int count = 0 ; QueryResult queryResult = null ; do { queryResult = db . query ( applyUserAgent ( queryRequest ) ) ; count += queryResult . getCount ( ) ; queryRequest . setExclusiveStartKey ( queryResult . getLastEvaluatedKey ( ) ) ; } while ( queryResult . getLastEvaluatedKey ( ) != null ) ; return count ; }
Evaluates the specified query expression and returns the count of matching items without returning any of the actual item data .