在SQL Server的表中插入2个外键

Question

我希望有人能给我一些想法！

我有以下3张桌子。它们是相关的：

CREATE TABLE [MemberDetails] (
[MemberID] int identity (1000,1) NOT NULL UNIQUE,
[MName] varchar(100) NOT NULL,
[MSurname] varchar(100) NOT NULL,
[MPhone] varchar(20) NOT NULL UNIQUE,
[MEmail] varchar(200) NOT NULL UNIQUE,
[MAddress] varchar(250) NOT NULL,
[MActive] char (1) NOT NULL CHECK (MActive IN ('Y','N')) DEFAULT 'Y',
[MUpdateDate] Date NOT NULL DEFAULT GETDATE(),
[MPhoto] Image NOT NULL,
[MDid] int NULL UNIQUE,
[MTid] int NULL UNIQUE,
PRIMARY KEY ([MemberID]),
FOREIGN KEY (MDid) REFERENCES [MembershipDetails] ([MDid]) ON DELETE SET NULL
                                                         ON UPDATE CASCADE,
FOREIGN KEY (MTid) REFERENCES [MarketingTarget] ([MTid]) ON DELETE SET NULL
                                                        ON UPDATE CASCADE    
);


 CREATE TABLE [MarketingTarget] (
 [MTid] int identity (5000,1) NOT NULL UNIQUE,
 [MDOB] date NOT NULL,
 [MSex] char NOT NULL CHECK (MSex IN ('M','F')) DEFAULT 'M',
 PRIMARY KEY ([MTid]),
 );


 CREATE TABLE [MembershipDetails] (
 [MDid] int identity (2000,1) NOT NULL UNIQUE,
 [MType] varchar(10) NOT NULL CHECK (MType IN ('Monthly','Quaterly','Yearly')) DEFAULT 'Monthly',
 [JoinDate] Date NOT NULL DEFAULT GETDATE(),
 [ExpiryDate] Date NULL,
 [MsUpdateDate] Date DEFAULT GETDATE(),
 PRIMARY KEY ([MDid])
 );

我想知道是否可以从其他两个表中自动将FK插入MemberDetails表中？我正在尝试编写存储过程。

我正在检查Scope_Identity，它可以获取生成的最后一个身份，但是我不确定如何正确使用它。

任何建议都将不胜感激！

谢谢，

Answer 1

这里是一个示例（表已缩短）：由于两个IDENTITY值都是必需的，因此我将它们保存到变量中，然后一起插入MemberDetail中。我建议为此事务进行交易。并看看TRY..CATCH。根据您的情况，您可能需要检查XACT_STATE（）。

https://docs.microsoft.com/en-us/sql/t-sql/language-elements/try-catch-transact-sql?view=sql-server-ver15

还有使用触发器的示例https://docs.microsoft.com/en-us/sql/t-sql/functions/scope-identity-transact-sql?view=sql-server-ver15

CREATE TABLE [_TEST_MemberDetails] (
[MemberID] int identity (1000,1) NOT NULL UNIQUE,
[MDid] int NULL UNIQUE,
[MTid] int NULL UNIQUE,
PRIMARY KEY ([MemberID]),
FOREIGN KEY (MDid) REFERENCES [_TEST_MembershipDetails] ([MDid]) ON DELETE SET NULL
                                                         ON UPDATE CASCADE,
FOREIGN KEY (MTid) REFERENCES [_TEST_MarketingTarget] ([MTid]) ON DELETE SET NULL
                                                        ON UPDATE CASCADE    
);


 CREATE TABLE [_TEST_MarketingTarget] (
 [MTid] int identity (5000,1) NOT NULL UNIQUE,
 [MDOB] date NOT NULL,
 [MSex] char NOT NULL CHECK (MSex IN ('M','F')) DEFAULT 'M',
 PRIMARY KEY ([MTid]),
 );


 CREATE TABLE [_TEST_MembershipDetails] (
 [MDid] int identity (2000,1) NOT NULL UNIQUE,
 [MType] varchar(10) NOT NULL CHECK (MType IN ('Monthly','Quaterly','Yearly')) DEFAULT 'Monthly',
 [JoinDate] Date NOT NULL DEFAULT GETDATE(),
 [ExpiryDate] Date NULL,
 [MsUpdateDate] Date DEFAULT GETDATE(),
 PRIMARY KEY ([MDid])
 );

 -- SP CODE START HERE
 SET XACT_ABORT ON;
 BEGIN TRY
     BEGIN TRANSACTION
     DECLARE @MTID int = 0, @MDID int = 0

     INSERT INTO _TEST_MarketingTarget ([MDOB], [MSex])
     VALUES ('Jan 1, 2020', 'M')
     SELECT @MTID = SCOPE_IDENTITY()

     INSERT INTO [_TEST_MembershipDetails] ([MType], [JoinDate], [ExpiryDate], [MsUpdateDate])
     VALUES (DEFAULT, DEFAULT, 'Jan 1, 2020', DEFAULT)
     SELECT @MDID = SCOPE_IDENTITY()

     INSERT INTO [_TEST_MemberDetails] (Mdid, MTid)
     SELECT @MDID, @MTID

     COMMIT TRANSACTION
END TRY
BEGIN CATCH
    IF @@TRANCOUNT <> 0 ROLLBACK TRANSACTION
END CATCH
go