为什么我的自动增量在 SQL Server 2008 中不起作用？

Question

这是我的表创建：

create table Movie 
(
     MovieID int NOT NULL IDENTITY (1,1) PRIMARY KEY, 
     MovieName varchar(40) NOT NULL UNIQUE, 
     CurrentStock int NOT NULL, 
     GenreID int NOT NULL,
     RatingID int NOT NULL, 
     Max_Inventory int NOT NULL, 
     Platforms char(5) NOT NULL, 
     Discontinued bit, 
     DiscontinuedDate Date
); 

create table Inventory
(
     InventoryID int NOT NULL IDENTITY (1,1) PRIMARY KEY, 
     MovieID int Not NULL,
     CurrentStock int NOT NULL, 
     Max_Inventory int NOT NULL
);

存储过程：

ALTER PROCEDURE [dbo].[InsInventory]
(@CurrentStock int,
 @ChangeStock int)
as
begin
  insert into Inventory(Max_Inventory, CurrentStock)
  Values (@ChangeStock, @CurrentStock)

  select SCOPE_IDENTITY();
END

ALTER PROCEDURE [dbo].[InsMovie] 
(@GenreID int,
 @RatingID int,
 @Platform varchar(5),
 @MovieName varchar(40)
)
AS
BEGIN
   Insert into Movie (RatingID, MovieName, Platforms, GenreID)
   Values (@RatingID, @MovieName, @Platform, @GenreID)

   select SCOPE_IDENTITY();

   SET NOCOUNT ON;
END

外键：

ALTER Table Inventory
ADD CONSTRAINT fk_Inventory_Movie 
FOREIGN KEY (MovieID) REFERENCES Movie(MovieID)

ALTER TABLE Movie
ADD CONSTRAINT fk_Movie_RatingLookUp
FOREIGN KEY (RatingID) REFERENCES RatingLookUp(RatingID)

ALTER TABLE Movie
ADD CONSTRAINT fk_Movie_GenreLookUp
FOREIGN KEY (GenreID) REFERENCES GenreLookUp (GenreID)

当我运行我的代码时，我在 Visual Studio 中不断收到错误

MovieID 不能为空

但它应该是当我插入一行时。我还确保手动检查 SQL Server 是否设置了IsIdentity，确实如此。所以请帮助一个困惑的程序员。

Answer 1

您不应该插入NULL 作为主键以使其生成值，您根本不应该插入该值，而不是将其列在要插入的字段中。作为样本；

INSERT INTO Movie (moviename, currentstock, genreid, ratingid, max_inventory, platforms)
                  VALUES ('name1', 1, 1, 1, 1, '1');

A simple working sample with your exact table creation.

Answer 2

以下陈述是您的问题。您的表 def 显示 MovieID 不为空。但在下面的声明中你没有提供。

insert into Inventory(Max_Inventory, CurrentStock)
Values (@ChangeStock, @CurrentStock)

这是您需要做的。首先您需要检索将在执行 InsMovie sproc 时返回的电影 ID。而不是您需要将该电影 ID 用作 InsInvetory sproc 调用的参数。

根据您的表格定义电影 id 是必需的。同样对于电影表，您错过了我添加的两列值，这也是必需的。

请查看更新的存储过程。

ALTER PROCEDURE [dbo].[InsInventory]
(

@CurrentStock int,
@ChangeStock int,
@MovieID int
)

as
begin
insert into Inventory(MovieID, Max_Inventory,CurrentStock)
    Values (@MovieID, @ChangeStock, @CurrentStock)

select SCOPE_IDENTITY();
END

ALTER PROCEDURE [dbo].[InsMovie] 
(
@GenreID int,
@RatingID int,
@Platform varchar(5),
@MovieName varchar(40),
@CurrentStock int, 
@max_inventory int
)
AS
BEGIN

Insert into Movie (CurrentStock, max_inventory, RatingID, MovieName, Platforms,GenreID)
    Values(@CurrentStock, @max_inventory, @RatingID,@MovieName, @Platform, @GenreID)

select SCOPE_IDENTITY();

SET NOCOUNT ON;


END