mysql group by分组查询后 查询个数
2个方法随便你选
select count(distinct colA) from table1;
select count(*) from (select colA from table1 group by colA) gyd;
用了子查询一定要用别名
newmiracle学习天地
mysql group by分组查询后 查询个数
2个方法随便你选
select count(distinct colA) from table1;
select count(*) from (select colA from table1 group by colA) gyd;
用了子查询一定要用别名
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