1. Oracle,随机查询查询语句-20条
select * from
( select * from 表名 order by dbms_random.value
) where rownum <= 20;
2.MSSQL Server,随机查询语句-20条
select top 20 * from 表名order by newid()
3.MySQL:,随机查询语句-20条
select * from 表名 order by rand() limit 20