摘要：
判断a表中有而b表中没有的记录select a.* from tbl1 a left join tbl2 bon a.key = b.keywhere b.key is null 虽然使用in也可以实现，但是这种方法的效率更高一些2． 新建一个与某个表相同结构的表select * into bfrom a where 113．between的用法,between限制查询数据范围时包括了边界值,not between不包括select * from table1 where time between time1 and time2select a,b,c, from table1 where . 阅读全文
