sql-server - 创建从多个表中删除数据的过程。SQL 服务器

Question

我需要创建一个过程，允许我一次从多个表中删除数据，搜索CUIT. 这里显示了四个表：

我必须传入一个CUIT值，如果它与数据库中保存的任何项目匹配，我需要将其删除。我找不到能够一次擦除两个以上表的语法，如果你能帮我一把，我将不胜感激。我怀疑该过程实际上要大得多，总共大约有 12 个表，但由于我只对语法感兴趣，所以我传递了这个片段。

我在尝试使用INNER JOIN.

我正在使用 SQL Server 2016。谢谢

标签： sql-serverstored-proceduressql-delete

Answer 1

考虑到您的设计，我会在您的外键上实现级联。这是一个示例，但应该让您走上正确的道路：

USE Sandbox;
GO

CREATE TABLE dbo.ParentTable (PK int IDENTITY PRIMARY KEY,
                              I int);

CREATE TABLE dbo.ChildTable1 (PK int IDENTITY PRIMARY KEY,
                              FK int,
                              S varchar(10));

CREATE TABLE dbo.ChildTable2 (PK int IDENTITY PRIMARY KEY,
                              FK int,
                              S varchar(10));

CREATE TABLE dbo.ChildTable3 (PK int IDENTITY PRIMARY KEY,
                              FK int,
                              S varchar(10));
GO
--Create keys with CASCADE ON DELETE
ALTER TABLE dbo.ChildTable1 ADD CONSTRAINT FK1 FOREIGN KEY (FK) REFERENCES dbo.ParentTable(PK) ON DELETE CASCADE;
GO
ALTER TABLE dbo.ChildTable2 ADD CONSTRAINT FK2 FOREIGN KEY (FK) REFERENCES dbo.ParentTable(PK) ON DELETE CASCADE;
GO
ALTER TABLE dbo.ChildTable3 ADD CONSTRAINT FK3 FOREIGN KEY (FK) REFERENCES dbo.ParentTable(PK) ON DELETE CASCADE;
GO


INSERT INTO dbo.ParentTable (I)
VALUES(1),(7),(9);

INSERT INTO dbo.ChildTable1 (FK,
                            S)
VALUES(1,'abc'),(3,'def');

INSERT INTO dbo.ChildTable2 (FK,
                            S)
VALUES(1,'xyz'),(2,'qwe');

INSERT INTO dbo.ChildTable3 (FK,
                            S)
VALUES(1,'123');
GO

SELECT *
FROM dbo.ParentTable PT
     LEFT JOIN dbo.ChildTable1 CT1 ON PT.PK = CT1.PK
     LEFT JOIN dbo.ChildTable2 CT2 ON PT.PK = CT2.PK
     LEFT JOIN dbo.ChildTable3 CT3 ON PT.PK = CT3.PK;

--1, as we're going to DELETE that
SELECT *
FROM dbo.ChildTable1 CT1
WHERE CT1.FK = 1;

SELECT *
FROM dbo.ChildTable1 CT2
WHERE CT2.FK = 1;

SELECT *
FROM dbo.ChildTable1 CT3
WHERE CT3.FK = 1;
GO

--Perform the DELETE, which will CASCADE to the child tables.    
DELETE FROM dbo.ParentTable
WHERE PK = 1;
GO
--no rows
SELECT *
FROM dbo.ParentTable PT
     LEFT JOIN dbo.ChildTable1 CT1 ON PT.PK = CT1.PK
     LEFT JOIN dbo.ChildTable2 CT2 ON PT.PK = CT2.PK
     LEFT JOIN dbo.ChildTable3 CT3 ON PT.PK = CT3.PK;

SELECT *
FROM dbo.ChildTable1 CT1
WHERE CT1.FK = 1;

SELECT *
FROM dbo.ChildTable1 CT2
WHERE CT2.FK = 1;

SELECT *
FROM dbo.ChildTable1 CT3
WHERE CT3.FK = 1;

GO
DROP TABLE dbo.ChildTable3;
DROP TABLE dbo.ChildTable2;
DROP TABLE dbo.ChildTable1;
DROP TABLE dbo.ParentTable;