select msgid,msgtype,userid,
(case msgtype
when '1' then (select username from users u where u.userid = m.userid)
else (select compname from company c where c.compid = m.userid)
end) as sname
from messages m这样符合你的要求吗?
(case msgtype
when '1' then (select username from users u where u.userid = m.userid)
else (select compname from company c where c.compid = m.userid)
end) as sname
from messages m这样符合你的要求吗?
解决方案 »
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