如何在T-SQL中将查询结果分配给局部变量

Question

我需要将多列的查询结果存储/分配给局部变量

例如;

declare @localVariable

select @localVariable = userId, userName, email, address 
from user;

相信以上代码不正确！

Answer 1

您需要为此声明一个表变量：

DECLARE @localVariable AS TABLE
(
    userId int,
    userName varchar(10),
    email nvarchar(100),
    address nvarchar(1000)
);

INSERT INTO @localVariable (userId, userName, email, address)
SELECT userId, userName, email, address
FROM [user];

Answer 2

您不能在select语句中混合使用变量赋值和数据检索。 这将不起作用：

DECLARE @localVariable INT;
SELECT TOP 1 @localVariable = userId, userName FROM user;

但这将：

-- copy values from multiple columns to variables
DECLARE @localVariable1 INT;
DECLARE @localVariable2 VARCHAR(100);
SELECT TOP 1 @localVariable1 = userId, @localVariable2 = userName FROM user;