1.group by 分组
将列名相同的记录分成一组
select * from table_name group by column_name
2.having 筛选分组后的条件
select * from table_name group by column_name having column2_name >1 (筛选条件)
3.in 规定where子句中的值
(1)in 包括where子句的值
select * from table_name where column_name in('淘宝','百度')
#查询table_name表中column_name列中包含淘宝或百度
(2)not in 不包括where子句的值
select * from table_name where column_name not in('淘宝','百度')
in或者 not in 条件里也可以放子查询语句,例如:
select * from table_name where column_name not in(select column_name2 from table2_name)