How to find all child rows in MySQL?

Question

I have a hierarchy system setup that stores the level and parent ID of the item in a database. What I am trying to figure out is how would I go about finding all the child rows

Answer 1

Refer, Recursive MySQL Query with relational innoDB

I had posted a answer yesterday for the same

Update:

Below is a function based on the above link, but has been tailored for your DELETE requirements

CREATE PROCEDURE `delete_relations`(`_id` INT)
BEGIN
DECLARE  delete_row_ids varchar(200);
DECLARE id, id2 varchar(200);
DECLARE rows_affected int;

SET delete_row_ids  = _id;
SET id              = _id;
SET id2             = id;

WHILE id2 IS NOT NULL DO 
    SET id = NULL;
    SELECT GROUP_CONCAT( hierarchical_data.id ), CONCAT( GROUP_CONCAT( hierarchical_data.ID ),',',delete_row_ids) INTO id, delete_row_ids FROM hierarchical_data WHERE FIND_IN_SET( parentid , id2 ) GROUP BY parentid ;
    SET id2 = id;
END WHILE;  

DELETE FROM hierarchical_data where FIND_IN_SET(hierarchical_data.id, delete_row_ids);
SELECT row_count() INTO rows_affected;

if rows_affected > 0 THEN
SELECT delete_row_ids as row_ids_deleted;
ELSE
SELECT 'NO_ROWS_DELETED';
END IF;

END//

SQLFiddle

Use

CALL delete_relations(1)

To delete all entries and its relations for id = 1 honda

Hope its helpful