递增数据插入表,我们还可以使用生成随机数来填充,建表的时候使用约束,不能重复,重复的话自然就不插入,继续生成下一个不重复的随机数。
还是以之前的为例,插入表中的数据为100-999。我们不谈性能(插入数据量小速度也很快的),只谈逻辑。
create table TestNum(num numeric(3,0) unique,check (num between 100 and 999)); go declare @num int set @num=(select COUNT(*) from TestNum) while (@num < 900) begin insert into TestNum select round(RAND(CHECKSUM(newid()))*1000,0) set @num = (select count(*) from TestNum) end; go select COUNT(*) from TestNum; go select * from TestNum order by 1; go
上面的插入可能只是某个需求中最基础的实现,比如下面的111000到111999,前面111不变,后面的改变。实际应用可以生成特定号码段的号码
create table TestNum(num numeric(6,0) unique,check (num between 111000 and 111999)); go declare @num int set @num=(select COUNT(*) from TestNum) while (@num < 1000) begin insert into TestNum select cast(‘111‘+right(‘000‘+convert(nvarchar(6),round(RAND(CHECKSUM(newid()))*1000,0)),3) as numeric(6,0)) set @num = (select count(*) from TestNum) end; go
原文:http://www.cnblogs.com/cnmarkao/p/3760581.html