how to delete all foreign keys for a table - mysql

Question

I am new to writing procedures , I have checked some of the stackoverflow posts but there is no post found to delete all foreign keys for a specific table.
I have a written below procedure.
drop procedure if exists remove_foreign_key;
delimiter ;;
create procedure remove_foreign_key(vTableName varchar(128)) begin
if exists (select table_name from information_schema.columns where table_schema=database() and table_name = vTableName) then
(SELECT concat('ALTER TABLE ', TABLE_NAME, ' DROP FOREIGN KEY ', CONSTRAINT_NAME, ';')
FROM information_schema.key_column_usage
WHERE table_schema=database() and TABLE_NAME = vTableName
AND referenced_table_name IS NOT NULL);
end if;
end if;
end;;
delimiter ;
call remove_foreign_key('my_table_name');
above query return me all queries(number of foreign keys that table contains) which needs to be executed, but I want to execute them one by one.I have read about cursor but not sure about its implementation.can someone help?

Answer 1

below is the mysql procedure to delete the foreign keys of some specific table's, hope it helps.you have to pass your table name in call and booom , your foreign keys are deleted for those tables.
DROP PROCEDURE IF EXISTS remove_foreign_key;
DELIMITER ;;
CREATE PROCEDURE remove_foreign_key(vTableName varchar(128))
BEGIN
DECLARE done INT DEFAULT FALSE;
DECLARE cName VARCHAR(64);
DECLARE cur CURSOR FOR
SELECT DISTINCT CONSTRAINT_NAME
FROM INFORMATION_SCHEMA.Key_COLUMN_USAGE
WHERE TABLE_SCHEMA=DATABASE() AND TABLE_NAME = vTableName
AND REFERENCED_TABLE_NAME IS NOT NULL;
DECLARE CONTINUE HANDLER FOR NOT FOUND SET done = TRUE;
SET AUTOCOMMIT=0;
SET FOREIGN_KEY_CHECKS=0;
OPEN cur;
read_loop: LOOP
FETCH cur INTO cName;
IF done THEN
LEAVE read_loop;
END IF;
SET #sql = CONCAT('ALTER TABLE ',vTableName,' DROP FOREIGN KEY ',cName,';');
PREPARE stmt FROM #sql;
EXECUTE stmt;
DEALLOCATE PREPARE stmt;
END LOOP;
CLOSE cur;
SET FOREIGN_KEY_CHECKS=1;
COMMIT;
SET AUTOCOMMIT=1;
END ;;
DELIMITER ;
call remove_foreign_key('table_name1');
call remove_foreign_key('table_name2');