Query on delete cascade not success in child table - mysql

Question

I have created two table that have a condition like this.
Parent
CREATE TABLE IF NOT EXISTS `tbl_requestfix` (
`id_request` varchar(10) NOT NULL,
`waktu_tutup_request` datetime DEFAULT NULL,
`id_complaint` varchar(10) NOT NULL,
PRIMARY KEY (`id_request`),
KEY `FK_tbl_requestfix_tbl_detail_complaint` (`id_complaint`),
CONSTRAINT `FK_tbl_requestfix_tbl_detail_complaint`
FOREIGN KEY
(`id_complaint`) REFERENCES `tbl_detail_complaint` (`id_complaint`)
ON DELETE CASCADE ON UPDATE CASCADE
) ENGINE=InnoDB DEFAULT CHARSET=latin1;
Child
CREATE TABLE IF NOT EXISTS `tbl_detail_complaint` (
`id_complaint` varchar(10) NOT NULL,
`complaint_2` text,
`timestamp_2` timestamp NULL DEFAULT CURRENT_TIMESTAMP,
PRIMARY KEY (`id_complaint`)
) ENGINE=InnoDB DEFAULT CHARSET=latin1;
When I am insert a row, there is no problem.
When I delete a row on parent, the row on child it still exist ?
Am I lost or wrong ?
DELETE FROM tbl_requestfix where id_request='001';
Thanks for the help. It so appreciated

Answer 1

You are calling this parent:
CREATE TABLE IF NOT EXISTS `tbl_requestfix` (
`id_request` varchar(10) NOT NULL,
`waktu_tutup_request` datetime DEFAULT NULL,
`id_complaint` varchar(10) NOT NULL,
PRIMARY KEY (`id_request`),
KEY `FK_tbl_requestfix_tbl_detail_complaint` (`id_complaint`),
CONSTRAINT `FK_tbl_requestfix_tbl_detail_complaint`
FOREIGN KEY
(`id_complaint`) REFERENCES `tbl_detail_complaint` (`id_complaint`)
ON DELETE CASCADE ON UPDATE CASCADE
) ENGINE=InnoDB DEFAULT CHARSET=latin1;
You are calling this child:
CREATE TABLE IF NOT EXISTS `tbl_detail_complaint` (
`id_complaint` varchar(10) NOT NULL,
`complaint_2` text,
`timestamp_2` timestamp NULL DEFAULT CURRENT_TIMESTAMP,
PRIMARY KEY (`id_complaint`)
) ENGINE=InnoDB DEFAULT CHARSET=latin1;
The fact is that you should be able to create Parent prior to creating Child. Parents come before the kids. But you can't create Parent first:
ERROR 1215 (HY000): Cannot add foreign key constraint
So I think you need to rethink this one.
Here is an example:
Schema:
-- drop table parent;
create table parent
( -- assume your have only one parent, ok bad example, it's early
id int auto_increment primary key,
fullName varchar(100) not null
)ENGINE=InnoDB;
-- drop table child;
create table child
( id int auto_increment primary key,
fullName varchar(100) not null,
myParent int not null,
CONSTRAINT `mommy_daddy` FOREIGN KEY (myParent) REFERENCES parent(id)
ON DELETE CASCADE ON UPDATE CASCADE
)ENGINE=InnoDB;
Test the cascade:
insert parent(fullName) values ('Robert Smith'),('Kim Billings'); -- id's 1 and 2
insert child(fullName,myParent) values ('Little Bobby',1),('Sarah Smith',1);
insert child(fullName,myParent) values ('Scout Billings',2),('Bart Billings',2);
select * from child;
+----+----------------+----------+
| id | fullName | myParent |
+----+----------------+----------+
| 1 | Little Bobby | 1 |
| 2 | Sarah Smith | 1 |
| 3 | Scout Billings | 2 |
| 4 | Bart Billings | 2 |
+----+----------------+----------+
delete from parent where id=1; -- delete Robert Smith
select * from child;
+----+----------------+----------+
| id | fullName | myParent |
+----+----------------+----------+
| 3 | Scout Billings | 2 |
| 4 | Bart Billings | 2 |
+----+----------------+----------+
There, the delete of the parent cascaded to clobber kids too