用于Tableau的MarkLogic ODBC-日期转换错误

Question

我有一个用于Tableau连接的MarkLogic ODBC服务器。我已经创建了视图，并且已经可以访问了。但是，在操作Tableau中的Date元素时遇到问题。我遇到以下错误：

An error occurred while communicating with the Other Databases (ODBC) data source 'database (new.database) (__MarkLogic)'.

Bad Connection: Tableau could not connect to the data source.
ERROR: XDMP-CAST: (err:FORG0001) Invalid cast: () cast as xs:date;
Error while executing the query
SELECT SUM("database"."amount") AS "sum_amount_ok",
  SUM("database"."offered") AS "sum_offered_ok",
  "database"."type" AS "type"
FROM "new"."database" "database"
WHERE (CAST({fn TRUNCATE(EXTRACT(YEAR FROM CAST("database"."date_of_permit" AS DATE)),0)} AS INTEGER) = 2014)
GROUP BY 3

在qconsole中运行此查询（除去{fn}标签）会导致相同的转换错误。我该如何解决？

谢谢！

更新： 正如grtjn所评论的那样，我的数据中存在一个空条目，这会导致此投射错误。