create table t(id int,name varchar(20),class int,score int);
select true score from t having max(score) > 80; /* ok */
select score from t having max(score) > 80; /* bad, score should appear in Group BY */
pg下测试ok。 这个true用法,是什么语法呀。
--
修改:saynothing FROM 115.195.253.*
FROM 115.195.253.*