SQL隨機查詢的方法

資料來源：http://www.flatws.cn/article/program/mysql/2010-08-23/8791.html


SQL Server：
Select TOP N * From TABLE Order By NewID()  
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Select TOP N * From TABLE Order By NewID()
Select TOP N * From TABLE Order By NewID()
NewID()函数将创建一个 uniqueidentifier 类型的唯一值。上面的语句实现效果是从Table中随机读取N条记录。
Access：
Select TOP N * From TABLE Order By Rnd(ID)   
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Select TOP N * From TABLE Order By Rnd(ID) 
Select TOP N * From TABLE Order By Rnd(ID)
Rnd(ID) 其中的ID是自动编号字段，可以利用其他任何数值来完成，比如用姓名字段(UserName)
Select TOP N * From TABLE Order BY Rnd(Len(UserName))  
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Select TOP N * From TABLE Order BY Rnd(Len(UserName))
Select TOP N * From TABLE Order BY Rnd(Len(UserName))
MySql：
Select * From TABLE Order By Rand() Limit 10  
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Select * From TABLE Order By Rand() Limit 10
Select * From TABLE Order By Rand() Limit 10

postgreSQL：
select * from glxt022 order by random() limit 5  
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select * from glxt022 order by random() limit 5