select count(1) from (
select
${IF(LEN(col)==0,"*","distinct '"+col+"'")}
from (
这么写,传参后结果是1
distinct ${IF(LEN(col)==0,"*",col)}
这么写,传参后结果是30是对的,但是想根据是否传参判断是否有distinct 怎么写呢?
distinct ${IF(LEN(col)==0,"*","distinct "+col)}
这样试试
${IF(LEN(col)==0,"*","distinct col")}