mysql drop foreign key code example
Example 1: mysql change foreign key
ALTER TABLE Orders
ADD FOREIGN KEY (PersonID) REFERENCES Persons(PersonID);
Example 2: mysql remove foreign key constraint
ALTER TABLE jobs DROP FOREIGN KEY constraint_name
Example 3: drop all foreign key constraints mysql
SET foreign_key_checks = 0;
Example 4: foreign key mySql
CREATE TABLE parent (
id INT NOT NULL,
PRIMARY KEY (id)
) ENGINE=INNODB;
CREATE TABLE child (
id INT,
parent_id INT,
INDEX par_ind (parent_id),
FOREIGN KEY (parent_id)
REFERENCES parent(id)
ON DELETE CASCADE
) ENGINE=INNODB;
Example 5: mysql drop key
ALTER TABLE tbl_quiz_attempt_master
DROP INDEX `PRIMARY`;