select * from table where gender=1 order by ... limit 10 union all select * from table where gender=2 order by ... limit 10
union的效率都不高了,就没啥高的了
要加个括号语法才对吧(select * from table where gender=1 order by ... limit 10) union all --这里使用 Union all (select * from table where gender=2 order by ... limit 10);
union all
select * from table where gender=2 order by ... limit 10
union all --这里使用 Union all
(select * from table where gender=2 order by ... limit 10);
[征集]分组取最大N条记录方法征集,及散分....