使用父母嵌套查询结果WHERE子句

Question

我有这样的查询与子查询as clicks 我想做的事情，然后where clicks > 0，但我得到一个错误，这不是一个公认的列。

SELECT top 10 *, (select count(*) FROM po_events aeclk WITH(NOLOCK) where (aeclk.[source] = ae.[source]) as clicks 

FROM archived_events ae with(NOLOCK) 
where clicks > 0 

Answer 1

虽然我与评论，这是一个可能重复的同意，我也想指出，相关子查询可能是低效的;二鸟一石，你可以这样做：的[参考列别名WHERE子句]

SELECT TOP 10 
     ae.* 
     , aeclk.clicks 
FROM archived_events ae 
     JOIN (SELECT source 
         , COUNT(*) AS clicks 
       FROM  po_events 
       GROUP BY source 
      ) aeclk ON aeclk.[source] = ae.[source] 
WHERE clicks > 0