SQL随机查询

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