从存储过程中输出最后插入的主键值

Question

我对这个有点困难，因为我不确定如何在 SQL Server 中执行此操作。

基本上，我想在数据库中插入一个新行，获取刚刚插入的 PK 值（相同的查询）并将其输出回所谓的存储过程：

CREATE PROCEDURE Users_Insert
    -- Add the parameters for the stored procedure here
    @userid int output,
    @name varchar(50),
    @surname varchar(50),
    @email varchar(200),
    @password varchar(50),
    @location varchar(50)
AS
BEGIN
    -- SET NOCOUNT ON added to prevent extra result sets from
    -- interfering with SELECT statements.
    SET NOCOUNT ON;

    -- Insert statements for procedure here
    insert into Users(FirstName, LastName, Email, Password, Location)
    values(@name, @surname, @email, @password, @location);
    GO
    @userid = @@IDENTITY;
END

我在 MySQL 中做了如下操作：

CREATE PROCEDURE Users_Insert(@userid int output, @name varchar(50), @surname varchar(50), @email varchar(200), @password varchar(50), @location varchar(50)
BEGIN

    insert into Users(FirstName, LastName, Email, Password, Location)
    values(@name, @surname, @email, @password, @location);

    set @userid = last_insert_id();
END

SQL Server 给我一个错误：

消息 102，级别 15，状态 1，过程 Users_Insert，第 18 行
'@userid' 附近的语法不正确。

坦率地说，我不确定我是否正确声明了输出参数，有人可以提供建议吗？

Answer 1

您需要将值分配给@userid！另外，我建议使用SCOPE_IDENTITY() 而不是@@IDENTITY：

CREATE PROCEDURE Users_Insert
    -- Add the parameters for the stored procedure here
    @userid int output,
    @name varchar(50),
    @surname varchar(50),
    @email varchar(200),
    @password varchar(50),
    @location varchar(50)
AS
BEGIN
    -- SET NOCOUNT ON added to prevent extra result sets from
    -- interfering with SELECT statements.
    SET NOCOUNT ON;

    -- Insert statements for procedure here
    insert into Users(FirstName, LastName, Email, Password, Location)
    values(@name, @surname, @email, @password, @location);

    -- make an actual **assignment** here...
    SELECT @userid = SCOPE_IDENTITY();
END

See this blog post for an explanation as to WHY you should use SCOPE_IDENTITY over @@IDENTITY