Esper 左外连接与子查询

Question

我正在尝试申请这个查询：

select a.partA, b.partB, b.count from call.win:time_batch(_WINDOW_) as a
left outer join (select count(*) count, partA from 
call.win:time_batch(_WINDOW_) group by partA ) b on a.partA = b.partA

但我遇到了异常

Caused by: com.espertech.esper.client.EPStatementSyntaxException: Incorrect syntax near '(' ('select' is a reserved keyword) at line 1 column 96, please check the outer join within the from clause near reserved keyword 'select' [select a.partA, b.partB, b.count from call.win:time_batch(WINDOW) as a left outer join(select count(*) count, partA from call.win:time_batch(WINDOW) group by partA ) b on a.partA = b.partA]

call 是我的事件类型名称

Answer 1

据我所知，从 5.4 版开始，Esper 中的 from 子句不支持子查询。

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