sql how to delete foreign key code example
Example 1: drop foreign key
ALTER TABLE table_name
DROP CONSTRAINT fk_name;
Example 2: mysql add foreign key
CREATE TABLE tableName (
ID INT,
SomeEntityID INT,
PRIMARY KEY (ID),
FOREIGN KEY (SomeEntityID)
REFERENCES SomeEntityTable(ID)
ON DELETE CASCADE
);
ALTER TABLE
tableName
ADD
FOREIGN KEY (SomeEntityID) REFERENCES SomeEntityTable(ID) ON DELETE CASCADE;
ALTER TABLE
tableName
ADD CONSTRAINT fk_name
FOREIGN KEY (SomeEntityID) REFERENCES SomeEntityTable(ID) ON DELETE CASCADE;
Example 3: how to remove foreign key constraint in sql
USE AdventureWorks2012;
GO
ALTER TABLE dbo.DocExe
DROP CONSTRAINT FK_Column_B;
GO