交集和差集 MySQL中没有这两个运算,但是有并集运算,所以可以利用这个来间接实现. 差集: SELECT ID FROM ( SELECT DISTINCT A.AID AS ID FROM TABLE_A A UNION ALL SELECT DISTINCT B.BID AS ID FROM TABLE_B B ) as TEMP GROUP BY ID HAVING COUNT(ID) = 1; 并集: SELECT ID FROM ( SELECT DISTINCT A.AID AS
1.返回日期的时间函数 date_add() : 可以为指定日期增加/减少任意一段时间间隔.下面举例将当前日期增加一个月和减少一个月 mysql month) as add_one_month; +---------------+ | add_one_month | +---------------+ | +---------------+ row in set (0.00 sec) mysql month) as reduce_one_month; +------------------+ |