---------- Forwarded message --------- 发件人： huang huang <lever0...@gmail.com> Date: 2020年12月17日周四 下午12:47 Subject: flink1.12.0中使用LISTAGG报错 To: <user...@flink.apache.org>
各位好： 使用pyflink执行sql时，LISTAGG出现了错误 请问目前版本的LISTAGG不支持排序么，有人遇到过这种情况么？ *FLINK版本：*1.12.0 *SQL代码：* SELECT session_id, LISTAGG(page_id, ',') WITHIN GROUP(ORDER BY action_time) as user_hit_log FROM user_action group by session_id *报错信息：* Caused by: org.apache.calcite.sql.validate.SqlValidatorException: Aggregate expression 'LISTAGG' must not contain a within group clause 如果有写法不对，请指正，感谢！ 根据查到的文档LISTAGG的用法，没看出来问题： Listagg is an *ordered set function*, which require the within group clause to specify an order. The minimal syntax is: LISTAGG(<expression>, <separator>) WITHIN GROUP(ORDER BY …) 参考链接： https://ci.apache.org/projects/flink/flink-docs-stable/dev/table/functions/systemFunctions.html#aggregate-functions https://modern-sql.com/feature/listagg
