1.更新表中某个字段为随机值

update [Courses] set LearnsNum = cast(rand(checksum(newid()))*(999-100)+100 as int)

以下可参考，非原创

update [test].[dbo].[table]
 set [table.rand] = cast(rand(checksum(newid()))*(999999-100000)+100000 as float(6))

 select newid()   如：57C26BA5-8304-4877-B5D4-256C80428B94
 select rand()     如：0.029051900701824
 select checksum(500)    如：500
 select checksum(newid())    如：35757911
 select rand(checksum(newid()))    如：0.657911662715189
 select rand(checksum(newid()))*(999999-100000)+100000    如：881621.124049528
 select cast(rand(checksum(newid()))*(999999-100000)+100000 as float(6))   如：609545.7