Error 1215: Cannot add foreign key constraint SQL Statement - mysql

Not sure why I am still encountering the issue "Error 1215" wherein they have the same data type and parent table is in primary key.
child table:
CREATE TABLE `customer_notice_type` (
`CUSTOMER_NOTICE_TYPE_ID` int(11) NOT NULL AUTO_INCREMENT,
`CUSTOMER_ID` int(11) NOT NULL,
`CUSTOMER_NOTICE_TYPE_NAME` varchar(50) NOT NULL,
`SYSTEM_NOTICE_TYPE_ID` int(11) NOT NULL,
`STATUS` char(1) NOT NULL,
`CREATED_BY` varchar(50) NOT NULL,
`CREATED_DATE` datetime NOT NULL,
`MODIFIED_BY` varchar(50) DEFAULT NULL,
`MODIFIED_DATE` datetime DEFAULT NULL,
PRIMARY KEY (`CUSTOMER_NOTICE_TYPE_ID`),
KEY `fk_customer_id_customer_notice_type_idx` (`CUSTOMER_ID`),
CONSTRAINT `fk_customer_id_customer_notice_type` FOREIGN KEY (`CUSTOMER_ID`) REFERENCES `customer` (`CUSTOMER_ID`) ON DELETE CASCADE ON UPDATE CASCADE
) ENGINE=InnoDB AUTO_INCREMENT=494 DEFAULT CHARSET=latin1;
parent table:
CREATE TABLE `system_notice_type` (
`SYSTEM_NOTICE_TYPE_ID` int(11) NOT NULL,
`SYSTEM_NOTICE_TYPE_NAME` varchar(45) NOT NULL,
`LINE_OF_BUSINESS_ID` int(11) NOT NULL,
`STATUS` char(1) NOT NULL,
PRIMARY KEY (`SYSTEM_NOTICE_TYPE_ID`)
) ENGINE=MyISAM AUTO_INCREMENT=16 DEFAULT CHARSET=latin1;
SQL script to create Foreign Key:
ALTER TABLE `fexpress`.`customer_notice_type`
ADD CONSTRAINT `fk_system_notice_type_customer_notice_type`
FOREIGN KEY (`SYSTEM_NOTICE_TYPE_ID`)
REFERENCES `fexpress`.`system_notice_type` (`SYSTEM_NOTICE_TYPE_ID`)
ON DELETE CASCADE ON UPDATE CASCADE;

You have two potential problems. First, the alter table statement references fexpress. This may or may not be the correct schema for the table. So, that is one potential problem.
The second real problem is the constraint defined in the child table:
CONSTRAINT `fk_customer_id_customer_notice_type` FOREIGN KEY (`CUSTOMER_ID`) REFERENCES `customer`(`CUSTOMER_ID`) ON DELETE CASCADE ON UPDATE CASCADE
The parent table is not yet defined, so it generates an error.
Removing this row and adjusting the schema name results in working code, as in this SQL Fiddle.

Related

Cannot add or update a child row: a foreign key constraint fails mysql

CREATE TABLE `class` (
`class_id` int(11) NOT NULL AUTO_INCREMENT,
`section_name` varchar(50) NOT NULL,
`class_alias` varchar(200) NOT NULL,
`grading_scheme` int(11) NOT NULL DEFAULT '0',
`year` year(4) NOT NULL,
`grade_calc_method_id` varchar(20) DEFAULT NULL,
PRIMARY KEY (`class_id`)
) ENGINE=InnoDB AUTO_INCREMENT=48819 DEFAULT CHARSET=latin1;
CREATE TABLE `teachers` (
`teacher_id` int(11) NOT NULL AUTO_INCREMENT,
`user_id` int(11) NOT NULL,
`teacher_subject` varchar(20) NOT NULL DEFAULT 'None',
PRIMARY KEY (`teacher_id`),
KEY `user_id` (`user_id`,`school_id`)
) ENGINE=InnoDB AUTO_INCREMENT=48606 DEFAULT CHARSET=latin1;
CREATE TABLE `teacher_classes` (
`teacher_class_id` int(11) NOT NULL AUTO_INCREMENT,
`teacher_id` int(11) NOT NULL,
`class_id` int(11) NOT NULL,
PRIMARY KEY (`teacher_class_id`),
UNIQUE KEY `teacher_id_class_id` (`teacher_id`,`class_id`),
KEY `teacher_id` (`teacher_id`,`class_id`)
) ENGINE=InnoDB AUTO_INCREMENT=46707 DEFAULT CHARSET=latin1;
Trying to insure data consistency between the tables by using foreign key so that the DBMS can check for errors.I have another junction table teacher_classes
Here is my query to add foreign keys constraint
ALTER TABLE teacher_classes
ADD CONSTRAINT `tc_fk_class_id` FOREIGN KEY (`class_id`)
REFERENCES class (`class_id`) ON UPDATE NO ACTION ON DELETE NO ACTION,
ADD CONSTRAINT `tc_fk_teacher_id` FOREIGN KEY (`teacher_id`)
REFERENCES teachers (`teacher_id`) ON UPDATE NO ACTION ON DELETE NO ACTION;
've seen the other posts on this topic, but no luck, getting following error.
Cannot add or update a child row: a foreign key constraint fails
(DB_NAME.#sql-403_12, CONSTRAINT
tc_fk_teacher_id FOREIGN KEY (teacher_id) REFERENCES teachers
(teacher_id) ON DELETE NO ACTION ON UPDATE NO ACTION)
Too late to Answer. I just had the same problem the solution is easy.
You're getting this error because you're trying to or UPDATE a row to teacher_classes doesn't match the id in table teachers.
A simple solution is disable foreign key checks before performing any operation on the table.
SET FOREIGN_KEY_CHECKS = 0;
After you are done with the table enable it again.
SET FOREIGN_KEY_CHECKS = 1;
Or you can remove not null constraint and insert a NULL value in it.
That's most probably the column definition doesn't match properly. For table teachers the PK column definition is as below.
`teacher_id` int(11) NOT NULL AUTO_INCREMENT
Make sure you have the same definition in your child table teacher_classes

MySQL error when trying to truncate table

I'm having problems to truncate a table on the MySQL Server 5.5.
The table I'm trying to truncate has a column that serves as a foreign key in another table.
The CREATE TABLE of both tables involved is as it follows:
CREATE TABLE `tbluser` (
`id` int(11) NOT NULL AUTO_INCREMENT,
`email` varchar(255) NOT NULL,
`password` varchar(255) NOT NULL,
`name` varchar(255) NOT NULL,
`creationDate` datetime NOT NULL,
`creationUserId` int(11) NOT NULL,
`updateDate` datetime NOT NULL,
`updateUserId` int(11) NOT NULL,
`lastAccess` datetime NOT NULL,
`enabled` tinyint(1) NOT NULL,
PRIMARY KEY (`id`),
UNIQUE KEY `id_UNIQUE` (`id`),
UNIQUE KEY `email_UNIQUE` (`email`),
KEY `FK_tbluser_creationUserId` (`creationUserId`),
KEY `FK_tbluser_updateUserId` (`updateUserId`),
CONSTRAINT `FK_tbluser_updateUserId` FOREIGN KEY (`updateUserId`) REFERENCES `tbluser` (`id`) ON DELETE CASCADE ON UPDATE CASCADE,
CONSTRAINT `FK_tbluser_creationUserId` FOREIGN KEY (`creationUserId`) REFERENCES `tbluser` (`id`) ON DELETE CASCADE ON UPDATE CASCADE
) ENGINE=InnoDB AUTO_INCREMENT=5 DEFAULT CHARSET=latin1;
CREATE TABLE `tblpost` (
`id` int(11) NOT NULL AUTO_INCREMENT,
`title` varchar(255) NOT NULL,
`content` mediumtext NOT NULL,
`creationDate` datetime NOT NULL DEFAULT '1901-01-01 00:00:00',
`creationUserId` int(11) NOT NULL,
`updateDate` datetime NOT NULL DEFAULT '1901-01-01 00:00:00',
`updateUserId` int(11) NOT NULL,
PRIMARY KEY (`id`),
KEY `FK_tblpost_creationUserId` (`creationUserId`),
KEY `FK_tblpost_updateUserId` (`updateUserId`),
CONSTRAINT `FK_tblpost_updateUserId` FOREIGN KEY (`updateUserId`) REFERENCES `tbluser` (`id`) ON DELETE CASCADE ON UPDATE CASCADE,
CONSTRAINT `FK_tblpost_creationUserId` FOREIGN KEY (`creationUserId`) REFERENCES `tbluser` (`id`) ON DELETE CASCADE ON UPDATE CASCADE
) ENGINE=InnoDB DEFAULT CHARSET=latin1;
Please note that all the constraints are both set to DELETE and UPDATE ON CASCADE.
When I try to TRUNCATE the table:
TRUNCATE TABLE `<databasename>`.`tbluser`;
I receive the following error message:
Cannot truncate a table referenced in a foreign key constraint
(`<databasename>`.`tblpost`,
CONSTRAINT `FK_tblpost_updateUserId`
FOREIGN KEY (`updateUserId`)
REFERENCES `<databasename>`.`tbluser` (`id`))
In addition to this information, there is the fact that when the action above is attempted on a MySQL Server 5.1, it works!
Does anyone have an idea of why this is happening?
Check here . That makes sense that TRUNCATE TABLE raises an error in such cases; the bad thing that it's not documented.

Error #1452 when altering mySQL table to add foreign key

Trying to help an intern with her project. She wants to add foreign keys to an existing table but this query:
ALTER TABLE `document`
ADD CONSTRAINT `document_ibfk_1` FOREIGN KEY (`cle_author`)
REFERENCES `author` (`id_author`)
ON DELETE CASCADE
ON UPDATE CASCADE;
gives this error:
ERROR 1452 (23000): Cannot add or update a child row: a foreign key constraint fails (`wrc_mysql`.<result 2 when explaining filename '#sql-30e4_7000d'>, CONSTRAINT `document_ibfk_1` FOREIGN KEY (`cle_author`) REFERENCES `author` (`id_author`) ON DELETE CASCADE ON UPDATE CASCADE)
Schema are like so
CREATE TABLE `document` (
`id_document` int(11) NOT NULL AUTO_INCREMENT,
`abstract` text,
`number_of_pages` int(10) DEFAULT NULL,
`original_surrey_citation` varchar(255) DEFAULT NULL,
`updated_citation` varchar(255) DEFAULT NULL,
`library_of_congress` varchar(10) DEFAULT NULL,
`cross_citation` varchar(50) DEFAULT NULL,
`doc_type` varchar(255) DEFAULT NULL,
`questions` varchar(255) DEFAULT NULL,
`keywords` varchar(255) DEFAULT NULL,
`cle_author` int(10) NOT NULL,
PRIMARY KEY (`id_document`),
KEY `cle_author` (`cle_author`)
) ENGINE=InnoDB AUTO_INCREMENT=22591 DEFAULT CHARSET=utf8
CREATE TABLE `author` (
`id_author` int(10) NOT NULL AUTO_INCREMENT,
`author_name` varchar(255) DEFAULT NULL,
`sender_office` varchar(255) DEFAULT NULL,
PRIMARY KEY (`id_author`),
KEY `author_name` (`author_name`,`sender_office`)
) ENGINE=InnoDB AUTO_INCREMENT=22591 DEFAULT CHARSET=utf8
Anyone know what is going wrong?
You probably have inconsistent data between your two tables. This error means that you have a cle_author value in your document table that doesn't have a corresponding entry in the author table. Since the cle_author value is going to be set up as a foreign key, each value for that field must have a corresponding entry in the author table's id_author field.
Per this page: Mysql error 1452 - Cannot add or update a child row: a foreign key constraint fails
checked intern's data with
SELECT cle_author FROM document doc
LEFT JOIN author a ON doc.cle_author=a.id_author
WHERE a.id_author IS NULL;
And found ALL of her cle_author data is bogus and does not hold valid references to id_author values.

MYSQL: Cannot add or update a child row: a foreign key constraint fails

I am getting the error:
Cannot add or update a child row: a foreign key constraint fails (mydb/requests, CONSTRAINT requests_ibfk_5 FOREIGN KEY (fixture_id) REFERENCES fixtures (fix_id) ON UPDATE CASCADE ON DELETE CASCADE)
I have the following table structure:
CREATE TABLE IF NOT EXISTS `requests` (
`request_id` int(11) unsigned NOT NULL auto_increment,
`fixture_id` int(11) unsigned NOT NULL,
`user_id` int(11) unsigned NOT NULL,
`date_added` datetime NOT NULL,
`date_modified` datetime default NULL,
PRIMARY KEY (`request_id`),
UNIQUE KEY `fixture_id_2` (`fixture_id`,`user_id`),
KEY `user_id` (`user_id`),
KEY `date_added` (`date_added`),
KEY `fixture_id` (`fixture_id`)
) ENGINE=InnoDB DEFAULT CHARSET=utf8 COLLATE=utf8_unicode_ci AUTO_INCREMENT=17 ;
CREATE TABLE IF NOT EXISTS `fixtures` (
`id` int(11) unsigned NOT NULL auto_increment,
`fix_id` int(11) unsigned NOT NULL default '0',
`fixture_date` date default NULL,
`kickoff` time default NULL,
`venue` varchar(35) default NULL,
`home_score` tinyint(4) default NULL,
`away_score` tinyint(4) default NULL,
`date_added` datetime default NULL,
`date_modified` datetime default NULL,
PRIMARY KEY (`id`),
UNIQUE KEY `fix_id` (`fix_id`),
KEY `fixture_date` (`fixture_date`),
) ENGINE=InnoDB DEFAULT CHARSET=utf8 AUTO_INCREMENT=383 ;
ALTER TABLE `requests`
ADD CONSTRAINT `requests_ibfk_2` FOREIGN KEY (`user_id`) REFERENCES `users` (`user_id`) ON DELETE CASCADE,
ADD CONSTRAINT `requests_ibfk_5` FOREIGN KEY (`fixture_id`) REFERENCES `fixtures` (`fix_id`) ON DELETE CASCADE ON UPDATE CASCADE;
If I update a record on the fix_id field the parent table (fixtures), that has a shared id (fixture_id) in the child table (requests) I get the above error.
I cannot see why this integrity constraint is failing. Both tables already have the correct data it should cascade through?
Any help greatly appreciated.
This was all my own error. I had two foreign constraints on the same field in reality. I just needed to take one off.
This error occurs due to the reference of other table, in both tables same id's/data should exist. If not please use where conditions to remove not existing data.
example
update tablename a set = 'field' (select field from othertable b) where a.data = b.data;

MySQL Foreign Key Constraint Confusion

Hey everyone, I have the following 'users' table in MySQL:
CREATE TABLE `users` (
`uid` int(11) NOT NULL auto_increment,
`fname` varchar(50) NOT NULL,
`lname` varchar(50) NOT NULL,
`role` varchar(75) NOT NULL,
`region` tinyint(4) unsigned default NULL,
`username` varchar(25) NOT NULL,
`password` varchar(75) NOT NULL,
`new_pass` varchar(5) default NULL,
PRIMARY KEY (`uid`),
UNIQUE KEY `username` (`username`),
KEY `role` (`role`),
KEY `region` (`region`),
CONSTRAINT `users_ibfk_3` FOREIGN KEY (`role`) REFERENCES `role` (`role`) ON DELETE CASCADE ON UPDATE CASCADE,
CONSTRAINT `users_ibfk_4` FOREIGN KEY (`region`) REFERENCES `region` (`region`) ON DELETE CASCADE ON UPDATE CASCADE
) ENGINE=InnoDB AUTO_INCREMENT=43 DEFAULT CHARSET=utf8
I have 'region' set as a foreign key to a region table - region.region'
Notice, that users.region is declared as NULL. I was under the impression that in MySQL, a foreign key contstraint is enforced ONLY if the key is set as NOT NULL.
However, when I try to insert a user with a NULL region in my PHP application, I get the following error:
ERROR: Cannot add or update a child row: a foreign key constraint fails (`reslife4/users`, CONSTRAINT `users_ibfk_4` FOREIGN KEY (`region`) REFERENCES `region` (`region`) ON DELETE CASCADE ON UPDATE CASCADE)
BUT, if I were to add this user outside of my PHP application, for example in phpMyAdmin, it would allow me to.
Does anyone know what's going on?
Your application puts a non-NULL value into region.
Enable the query log and see what exactly your PHP tries to insert into the table.