可以使用 HAVING 子句进行删除吗? [英] Possible to do a delete with a HAVING clause?

问题描述

我想做如下事情:

DELETE UserPredictions
  GROUP BY UserId
  HAVING COUNT(*) < 500

但是我遇到了语法错误.甚至可以在 SQL Server 中使用 HAVING 子句进行删除，还是必须将计数汇总到 CTE 中并使用连接进行删除?

But I'm getting a syntax error. Is it even possible to do a delete with a HAVING clause in SQL Server or will I have to roll the counts up into a CTE and do a delete with a join?

推荐答案

并非如此.have 子句意味着聚合，这意味着您不再拥有原始行.

Not really. The having clause implies an aggregation, which means you don't have the original rows any more.

我认为您需要以下内容:

I think you want the following:

DELETE from UserPredictions
where UserId in (select UserId from UserPredictions group by UserId having count(*) < 500)

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