#set($locationid = $util.defaultIfNullOrBlank($ctx.args.locationid, $ctx.source.locationid))
        {
          "version" : "2018-05-29",
          "operation" : "Query",
          "query" : {
              "expression": "locationid = :locationid",
              "expressionValues" : {
                  ":locationid" : $util.dynamodb.toDynamoDBJson($locationid)
              }
          },
          "index": "locationidGSI"
        }