mysql insert FK code example
Example 1: 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 2: fk in insert mysql
INSERT INTO joke(joke_text, joke_date, author_id)
VALUES (‘Humpty Dumpty had a great fall.’, ‘1899–03–13’,
(SELECT id FROM author WHERE author_name = ‘Famous Anthony’));