利用sql语句随机抽取记录

1. Oracle,随机查询20条

select * from
(
select  *  from 表名
order by dbms_random.value
)
where rownum <= 20;

2.MS SQL Server，随机查询20条

select top 20  * from  表名 order by newid()

3.My SQL:，随机查询20条

select  *  from  表名 order by rand() limit 20

4.SQLite:，随机查询20条

select * from 表名 order by random() limit 20