查询语句

[rorom]

这个sql有人帮我优化一下吗?

select * from ky_message where msg_to='系统' or msg_to=? or msg_title=? or msg_title=? or msg_title=? order by msg_id desc

[ACMAIN_CHM]

show index from ky_message贴出来你的索引情况。

[guangzi477273]

select * from ky_message where msg_to='系统' or msg_to=? or msg_title=? or msg_title=? or msg_title=? order by msg_id desc
给msg_id建立clustered index(desc)
并使用in如：
select *from ky_message where msg_to in ('系统','?')
or msg_title in (?,?)
可以考虑使用union句子合并查询比如：
select * from ky_message where msg_to in('系统'，'？')
union
select * from ky_message where msg_title in(?,?);

[jsjhushilei]

show index from ky_message

[iamayuan]

学习学习

[rorom]

哦,索引是没有的,只有msg_id是主键.

[MicalLi]

select *from ky_message where msg_to in ('系统','?')
or msg_title in ('?','?','?')
order by msg_id desc