sql server：
复制代码 代码如下:
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：
复制代码 代码如下:
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)
复制代码 代码如下:
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：
复制代码 代码如下:
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：
复制代码 代码如下:
select * from glxt022 order by random() limit 5
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select * from glxt022 order by random() limit 5