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Sql 选择内部联接上的计数(*)_Sql - Fatal编程技术网

Sql 选择内部联接上的计数(*)

Sql 选择内部联接上的计数(*),sql,Sql,有人能纠正这句话或使它更有效率吗。谢谢各位: SET @intAnswer = (SELECT COUNT(*) FROM episode INNER JOIN episodejoin ON episode.epi_id = episodejoin.epj_epi_id_dest INNER JOIN episodetype ON episode.epi_ety_id = episodetype.ety_id WHERE (episodejoin.epj_epi_id_src = @Episo

有人能纠正这句话或使它更有效率吗。谢谢各位:

SET @intAnswer =  (SELECT COUNT(*)
FROM episode INNER JOIN
episodejoin ON episode.epi_id = episodejoin.epj_epi_id_dest INNER JOIN
episodetype ON episode.epi_ety_id = episodetype.ety_id
WHERE (episodejoin.epj_epi_id_src = @EpisodeID)

当前的声明有什么问题?在join和where子句中使用的列上有索引吗?嗨。感谢您的快速回复!这是大学的考题,问题是这个陈述有什么问题,你会怎么写这个陈述?或者你认为这句话合法吗?嗯,考虑到它应该用作字典表,你很可能不需要加入到
epiodetype
。谢谢!那么,除了join eposodetype之外,您的专家认为该语句将成功返回计数?那么,除了join eposodetype之外,您的专家认为该语句将成功返回计数?如果你认为这份声明还有什么不对的地方,请告诉我。我已经将SELECT@intAnswer=count()更改为设置“@intAnswer=(SELECT count()”