下面将为您介绍sql变量从select,insert获取值的单值情况及记录集情况的操作，供您参考，希望对您学习sql变量会有所帮助。

use Northwind

--整形sql变量的赋值

declare @addr int
set @addr = (select sum(power(2,cast(EmployeeID as integer))) as addr from employees )
print '员工id的平方和为：'+cast(@addr as varchar(10))

--浮点数sql变量的赋值

declare @total float
set @total = (select sum(freight) as freight from Orders)
print '所有商品的总运费为：'+cast(@total as varchar(10))

--记录集sql变量的赋值

declare @tb table(id int,name varchar(20),country varchar(20))
insert into @tb select employeeid,firstname+' '+lastname,country from employees
select * from @tb
select a.name,b.customerId,b.freight from @tb a,orders b where a.id=b.employeeid

关键点：单值情况下，select一定要用括号

【编辑推荐】

Transact-SQL变量的声明

设置Transact-SQL变量中的值

SQL变量定义赋值及调用

教您使用SQL参数变量来传递记录值

SQL中的指示变量及数组变量