如何在GROUP BY子句中添加XML数据类型？

您可以在CTE中进行汇总，然后加入该汇总中

WITH Children(Cnt, ParentId)     AS (SELECt COUNT(*),     ParentId         FROM   dbo.Post         GROUP  BY ParentId)SELECt P.PostId,       P.[Body],       ISNULL(Cnt, 0) AS CntFROM   dbo.Post P       LEFT JOIN Children          ON Children.ParentId = P.PostIdORDER  BY P.PostId