Hey I'm having issues setting foreign keys pointing from my followings table:
CREATE TABLE `followings` (
`id` int(26) NOT NULL,
`userid` varchar(256) NOT NULL,
`followerid` varchar(256) NOT NULL,
`time` timestamp NOT NULL DEFAULT current_timestamp()
) ENGINE=InnoDB DEFAULT CHARSET=utf8mb4;
to my users table:
CREATE TABLE `users` (
`id` int(26) NOT NULL,
`userid` varchar(256) NOT NULL,
`handle` varchar(256) NOT NULL,
`email` varchar(256) NOT NULL,
`password` varchar(256) NOT NULL,
`phone` varchar(256) NOT NULL,
`dateofbirth` varchar(99) NOT NULL,
`phoneverified` varchar(25) DEFAULT NULL,
`emailverified` varchar(25) DEFAULT NULL,
`authentic` tinyint(1) NOT NULL DEFAULT 0,
`datecreated` timestamp NOT NULL DEFAULT current_timestamp()
) ENGINE=InnoDB DEFAULT CHARSET=utf8mb4;
ALTER TABLE `users`
ADD PRIMARY KEY (`id`),
ADD UNIQUE KEY `userid` (`userid`),
ADD UNIQUE KEY `handle` (`handle`);
I have checked the collation etc of the fields are the same yet i am still getting an error on phpmyadmin
Error creating foreign key on userid, followerid (check data types)
Any possible reasons for such error
This is the sql generated by phpmyadmin before the error
ALTER TABLE `followings` ADD FOREIGN KEY (`userid`, `followerid`) REFERENCES `users`(`userid`, `userid`) ON DELETE RESTRICT ON UPDATE RESTRICT;
You shouldn't be making a multi-key foreign key. You need separate foreign keys for userid and followerid, since they refer to different rows in the users table.
ALTER TABLE followings ADD FOREIGN KEY (userid) REFERENCES users (userid);
ALTER TABLE followings ADD FOREIGN KEY (followerid) REFERENCES users (userid);
Also, it's usually preferable to have the foreign key reference the primary key.
Related
I´m trying to create Foreign Keys in phpmyadmin, but I get this error:
Error creating foreign key on revision (check data types)
I don´t understand it because the data types are equal. So, what I want is to create a Foreign Key from 'acoustictreatment' to 'filterspecifications' which contains tag, offerid and revision. But I get the error that I mentioned.
This are my tables:
CREATE TABLE `offer` (
`projectid` varchar(20) NOT NULL,
`customer` varchar(255) NOT NULL,
`creator` varchar(255) NOT NULL,
`date` date NOT NULL,
`revision` int(11) NOT NULL
) ENGINE=InnoDB DEFAULT CHARSET=utf8mb4;
ALTER TABLE `offer`
ADD PRIMARY KEY (`projectid`,`revision`);
CREATE TABLE `filterspecifications` (
`tag` varchar(100) NOT NULL,
`gasFlow` double NOT NULL,
`dustToHandle` double NOT NULL,
`offerid` varchar(20) NOT NULL,
`selectedFilter` varchar(20) NOT NULL,
`revision` int(11) NOT NULL
) ENGINE=InnoDB DEFAULT CHARSET=utf8mb4;
ALTER TABLE `filterspecifications`
ADD PRIMARY KEY (`tag`,`offerid`,`revision`),
ADD KEY `offerid` (`offerid`,`revision`);
ALTER TABLE `filterspecifications`
ADD CONSTRAINT `filterspecifications_ibfk_1`
FOREIGN KEY (`offerid`,`revision`) REFERENCES `offer` (`projectid`, `revision`) ON DELETE CASCADE ON UPDATE CASCADE;
CREATE TABLE `acoustictreatment` (
`tag` varchar(100) NOT NULL,
`offerid` varchar(20) NOT NULL,
`outputFanSilencer` tinyint(1) NOT NULL,
`fanAcousticInsulation` tinyint(1) NOT NULL,
`revision` int(11) NOT NULL
) ENGINE=InnoDB DEFAULT CHARSET=utf8mb4;
ALTER TABLE `acoustictreatment`
ADD PRIMARY KEY (`tag`,`offerid`,`revision`);
The solution that I found is to delete the 'acoustictreatment' table and create it again with the foreign key from the beginning. Because what I was trying to do was to create all the tables and then create the foreign keys, but that didn´t work for me
I tried to excute the query. but a error was occurred. the error message is 'Cannot add foreign key constraint'.
I supposed to create this table. but it didn't work.
CREATE TABLE IF NOT EXISTS `mydb`.`member` (
`idseq` INT(1) NOT NULL AUTO_INCREMENT,
`id` VARCHAR(50) NOT NULL,
`pw` VARCHAR(20) NOT NULL,
`name` VARCHAR(50) NOT NULL,
`email` VARCHAR(45) NOT NULL,
`mobile0` VARCHAR(3) NOT NULL,
`mobile1` VARCHAR(3) NOT NULL,
`mobile2` VARCHAR(4) NOT NULL,
`mobile3` VARCHAR(4) NOT NULL,
`birth` DATE NOT NULL,
`admin_YN` VARCHAR(45) NOT NULL DEFAULT 'N',
`reg_date` DATE NOT NULL,
`upd_date` DATE NOT NULL,
PRIMARY KEY (`idseq`, `id`))
ENGINE = InnoDB
AUTO_INCREMENT = 6
DEFAULT CHARACTER SET = utf8;
CREATE TABLE IF NOT EXISTS `mydb`.`reservation` (
`reservation_seq` INT(11) NOT NULL AUTO_INCREMENT,
`user_id` VARCHAR(50) NOT NULL,
`playMv_seq` INT(11) NOT NULL,
`reservaion_seat_code` VARCHAR(20) NOT NULL,
`reservaion_seat_num` INT(11) NOT NULL,
`reservation_charge` VARCHAR(20) NOT NULL,
`reservation_date` DATETIME NOT NULL,
PRIMARY KEY (`reservation_seq`, `user_id`, `playMv_seq`),
FOREIGN KEY (`user_id`)
REFERENCES `mydb`.`member` (`id`)
)
ENGINE = InnoDB
AUTO_INCREMENT = 8
DEFAULT CHARACTER SET = utf8;
So I checked it detail from a query'show engine innodb status. the detail error message is
Error in foreign key constraint of table mydb/reservation:
FOREIGN KEY (`user_id`)
REFERENCES `mydb`.`member` (`id`)
Cannot find an index in the referenced table where the
referenced columns appear as the first columns, or column types
in the table and the referenced table do not match for constraint.
Note that the internal storage type of ENUM and SET changed in
tables created with >= InnoDB-4.1.12, and such columns in old tables
cannot be referenced by such columns in new tables.
how can I resolve the error
You're trying to create a foreign key referencing the id column of the target table:
FOREIGN KEY (`user_id`)
REFERENCES `mydb`.`member` (`id`)
But what is the actual key on that target table?:
PRIMARY KEY (`idseq`, `id`)
It's not id, if the composite of idseq and id. In order to reference that as a foreign key, you need local columns which match that:
`user_idseq` INT(1) NOT NULL,
`user_id` VARCHAR(50) NOT NULL,
And use both of them for the foreign key:
FOREIGN KEY (`user_idseq`, `user_id`)
REFERENCES `mydb`.`member` (`idseq`, `id`)
(Side Note: That primary key in member looks pretty strange to me in the first place. Why can't idseq by itself be the primary key? What is the purpose of id?)
I can't figure out why I'm getting an error here.
CURRENT TABLES:
CREATE TABLE `Clients` (
`ClientID` varchar(8) NOT NULL,
`Age` varchar(20) NOT NULL,
`Postcode` varchar(6) NOT NULL,
PRIMARY KEY (`ClientID`,`Age`,`Postcode`)
) ENGINE=InnoDB DEFAULT CHARSET=latin1;
CREATE TABLE `Disclosure` (
`ClientID` varchar(8) NOT NULL,
`Fname` varchar(100) DEFAULT NULL,
`Lname` varchar(100) DEFAULT NULL,
`Email` varchar(100) DEFAULT NULL,
`Postcode` varchar(6) NOT NULL,
`Offender` varchar(45) DEFAULT NULL,
`Location` varchar(100) DEFAULT NULL,
`Age` varchar(20) NOT NULL,
`Support` varchar(45) DEFAULT NULL,
`Disclosure` varchar(1000) DEFAULT NULL,
PRIMARY KEY (`ClientID`,`Postcode`,`Age`)
) ENGINE=InnoDB DEFAULT CHARSET=latin1;
trying to add foreign key
ALTER TABLE `FYP`.`Disclosure`
ADD CONSTRAINT `client`
FOREIGN KEY (`ClientID` , `Postcode` , `Age`)
REFERENCES `FYP`.`Clients` (`ClientID` , `Postcode` , `Age`)
ON DELETE NO ACTION
ON UPDATE CASCADE;
I've tried using show status to see what the error is but I still cant figure it out.
SHOW ENGINE INNODB STATUS
returns:
------------------------ LATEST FOREIGN KEY ERROR
------------------------ 171102 11:35:10 Error in foreign key constraint of table FYP/#sql-266_33b:
FOREIGN KEY (ClientID , Postcode , Age) REFERENCES
FYP.Clients (ClientID , Postcode , Age) ON DELETE NO
ACTION ON UPDATE CASCADE: Cannot find an index in the referenced
table where the referenced columns appear as the first columns, or
column types in the table and the referenced table do not match for
constraint. Note that the internal storage type of ENUM and SET
changed in tables created with >= InnoDB-4.1.12, and such columns in
old tables cannot be referenced by such columns in new tables. See
http://dev.mysql.com/doc/refman/5.5/en/innodb-foreign-key-constraints.html
for correct foreign key definition.
You need an index on the referenced columns. The order of the columns in an index matter. In the clients table change the primary key to
(`ClientID`,`Postcode`,`Age`)
This should do it
ALTER TABLE clients DROP PRIMARY KEY, ADD PRIMARY KEY (`ClientID`,`Postcode`,`Age`);
I have two related tables: Groups and Clients. Clients belongs to Groups so I have a foreign key "group_id" that references the group a client belongs to.
I'm changing the Group id from an autoincrement to a UUID. So what I need is to generate a UUID for each Group and update the Clients table at once to reflect the changes and keep the records related.
Is there a way to do this with multiple-table update on MySQL?
Adding tables definitions for clarification.
CREATE TABLE `groups` (
`id` char(36) NOT NULL,
`name` varchar(255) DEFAULT NULL,
`created` datetime DEFAULT NULL,
`modified` datetime DEFAULT NULL,
PRIMARY KEY (`id`)
) ENGINE=InnoDB DEFAULT CHARSET=utf8$$
CREATE TABLE `clients` (
`id` char(36) NOT NULL,
`name` varchar(255) NOT NULL,
`group_id` char(36) DEFAULT NULL,
`active` tinyint(1) DEFAULT '1'
PRIMARY KEY (`id`),
KEY `fkgp` (`group_id`),
CONSTRAINT `fkgp` FOREIGN KEY (`group_id`) REFERENCES `groups` (`id`)
ON DELETE NO ACTION ON UPDATE CASCADE
) ENGINE=InnoDB DEFAULT CHARSET=utf8$$
I have a table with a compound primary key "name" and "id". The fields are actually "name","id","phone","amount","units","alias". I have the query
insert into MyTable (name,id,phone,amount) select "henry" as name, id,phone,amount from anotherTable
on duplicate key update phone=values(phone),amount=values(amount).
MySQL spits the following error:
Cannot add or update a child row: a foreign key constraint fails.
BTW, "id" is a foreign key.
Any help?
as requested below, the schema for other table is
CREATE TABLE `otherTable` (
`otherId` int(11) NOT NULL AUTO_INCREMENT,
`DOBId` int(11) NOT NULL,
`bankAccount` int(11) DEFAULT NULL,
`partialAmount` int(11) NOT NULL DEFAULT '0',
`id` int(11) NOT NULL,
`timestamp` timestamp NOT NULL DEFAULT CURRENT_TIMESTAMP,
`notes` varchar(299) DEFAULT NULL,
`latitude` decimal(8,5) DEFAULT NULL,
`longitude` decimal(8,5) DEFAULT NULL,
PRIMARY KEY (`otherId `),
KEY `DOBId ` (`DOBId `),
KEY `bankAccount ` (`bankAccount `),
KEY `id ` (`id `)
) ENGINE=InnoDB AUTO_INCREMENT=3305 DEFAULT CHARSET=utf8;
for myTable
CREATE TABLE `myTable` (
`name` int(11) NOT NULL,
`id` int(11) NOT NULL,
`appleNumber` int(11) DEFAULT NULL,
`amount` int(11) DEFAULT NULL,
`windowsNumber` int(11) DEFAULT NULL,
`phone` int(11) DEFAULT NULL,
`pens` int(11) DEFAULT NULL,
`pencils` int(11) DEFAULT NULL,
PRIMARY KEY (`name`,`id`),
KEY `id` (`id`),
CONSTRAINT `myTable_ibfk_1` FOREIGN KEY (`id`) REFERENCES `yet_another` (`id`)
The problem appears to be that the FK constraint you have on myTable is referencing the ids of yet_another, so when you are inserting ids from anotherTable you are breaking this FK constraint. Chances are there are ids in anotherTable that do not exist in yet_another table.
Understand this is a shot in the dark, based on the abstracted schema you posted. If you want a more solid answer, I'd have to see the actual schema.
The on duplicate key applies to the primary key. I take it you're using innodb. This is failing on a foreign key constraint. Which values of you table MyTable are foreign keys? Please post the create statement for the table that shows all keys and constraints for more detailed help.
Just a guess, but for grins I'm betting it's a column that's not in the insert that is a foreign key not allowing a null value.