Adding new column to table as foreign key - mysql

I am having difficult time trying to add a column to my sql table that will be a foreign key to another table. I'm getting the following error:
You have an error in your SQL syntax; check the manual that corresponds to your MySQL server version for the right syntax to use near ''description_id' INT,
ADD FOREIGN KEY (description_id)
REFERENCES description(de' at line 2
From my query:
ALTER TABLE images
ADD COLUMN 'description_id' INT,
ADD FOREIGN KEY (description_id)
REFERENCES description(description_id)
Here is my table, where I am trying to add the column to:
CREATE TABLE `images` (
`id` int(5) NOT NULL AUTO_INCREMENT,
`pattern` varchar(225) DEFAULT NULL,
`color` varchar(225) DEFAULT NULL,
`imageUrl` varchar(225) DEFAULT NULL,
`imageSource` varchar(225) DEFAULT NULL,
PRIMARY KEY (`id`)
) ENGINE=InnoDB AUTO_INCREMENT=47 DEFAULT CHARSET=latin1;
Here is the table that is being connected:
CREATE TABLE `description` (
`description_id` int(11) NOT NULL,
`color` varchar(255) DEFAULT NULL,
`pattern` varchar(255) DEFAULT NULL,
`body` varchar(255) DEFAULT NULL,
PRIMARY KEY (`description_id`)
) ENGINE=InnoDB DEFAULT CHARSET=latin1;

You can't ALTER TABLE ADD, ADD. Try:
ALTER TABLE images
ADD COLUMN 'description_id' INT
REFERENCES description(description_id)

Related

Why I am having a this error on phpmyadmin: Error creating foreign key on revision (check data types)?

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

MySQL FOREIGN KEY Constraints Syntax

When I'm going to execute this code, I'm getting this error message:
You have an error in your SQL syntax; check the manual that
corresponds to your MySQL server version for the right syntax to use
near 'ADD CONSTRAINT fk_pay_grade_scale FOREIGN KEY pay_scale_id
REFERENCES `pay_s' at line 11
But I don't understand the problem. Your help is appreciated!
CREATE TABLE IF NOT EXISTS `pay_grades` (
`pay_grade_id` int(20) NOT NULL,
`pay_scale_id` tinyint(4) NOT NULL,
`name` varchar(100) NOT NULL,
`basic_salary` decimal(10,2) NOT NULL,
`status` int(2) NOT NULL DEFAULT '1',
PRIMARY KEY (`pay_grade_id`),
INDEX (`pay_scale_id`, `pay_grade_id`),
ADD CONSTRAINT `fk_pay_grade_scale` FOREIGN KEY `pay_scale_id` REFERENCES `pay_scales`(`id`) ON UPDATE CASCADE ON DELETE RESTRICT
) ENGINE=InnoDB DEFAULT CHARSET=utf8;
CREATE TABLE IF NOT EXISTS `pay_scales` (
`id` tinyint(4) NOT NULL,
`name` varchar(100) NOT NULL,
PRIMARY KEY(id)
) ENGINE=InnoDB DEFAULT CHARSET=utf8;
You can not use ADD CONSTRAINT in a CREATE TABLE declaration.
Declare your constraint after creating the table or in the CREATE TABLE.
First solution: Add the constraint in CREATE TABLE
CREATE TABLE IF NOT EXISTS `pay_grades` (
`pay_grade_id` int(20) NOT NULL,
`pay_scale_id` tinyint(4) NOT NULL,
`name` varchar(100) NOT NULL,
`basic_salary` decimal(10,2) NOT NULL,
`status` int(2) NOT NULL DEFAULT '1',
PRIMARY KEY (`pay_grade_id`),
INDEX (`pay_scale_id`, `pay_grade_id`),
FOREIGN KEY (`pay_scale_id`) REFERENCES `pay_scales`(`id`) ON UPDATE CASCADE ON DELETE RESTRICT
) ENGINE=InnoDB DEFAULT CHARSET=utf8;
Second solution: Alter table to add the constraint
Create your table without the constraint, and then add your constraint as follow:
ALTER TABLE `pay_grades`
ADD CONSTRAINT `pay_scale_id` FOREIGN KEY REFERENCES `pay_scales`(`id`)
ON UPDATE CASCADE ON DELETE RESTRICT;
MySQL documentation for foreign keys declaration.
It seems the difference in order of table creation. First create primary key table than create the table of foreign key.
CREATE TABLE IF NOT EXISTS `pay_scales` (
`id` tinyint(4) NOT NULL,
`name` varchar(100) NOT NULL,
PRIMARY KEY(id)
) ENGINE=InnoDB DEFAULT CHARSET=utf8;
CREATE TABLE IF NOT EXISTS `pay_grades` (
`pay_grade_id` int(20) NOT NULL,
`pay_scale_id` tinyint(4) NOT NULL,
`name` varchar(100) NOT NULL,
`basic_salary` decimal(10,2) NOT NULL,
`status` int(2) NOT NULL DEFAULT '1',
PRIMARY KEY (`pay_grade_id`),
INDEX (`pay_scale_id`, `pay_grade_id`),
ADD CONSTRAINT `fk_pay_grade_scale` FOREIGN KEY `pay_scale_id` REFERENCES `pay_scales`(`id`) ON UPDATE CASCADE ON DELETE RESTRICT
) ENGINE=InnoDB DEFAULT CHARSET=utf8;

table creation query showing error

I am trying to create a table it is showing following error
#1064 - You have an error in your SQL syntax; check the manual
that corresponds to your MySQL server version for the right syntax
to use near ''duration' bigint (10) DEFAULT NULL,
'small_img' varchar(100) DEFAULT NULL' at line 6
Query is
CREATE TABLE videos_description(
`video_id` bigint(200) NOT NULL AUTO_INCREMENT,
`video_path` varchar(200) NOT NULL ,
`video_title` varchar(200) NOT NULL ,
`description` text DEFAULT NULL,
'duration' bigint (10) DEFAULT NULL,
'small_img' varchar(100) DEFAULT NULL,
'large_img' varchar(100) DEFAULT NULL,
`source_site` varchar(100) DEFAULT NULL,
`sent_by` int(20) DEFAULT NULL,
`received_by` int(20) DEFAULT NULL,
`message_id` bigint(200) DEFAULT NULL,
`visibility` varchar(30) DEFAULT NULL,
`adddate` timestamp NOT NULL DEFAULT CURRENT_TIMESTAMP,
PRIMARY KEY (video_id),
FOREIGN KEY (`received_by`) REFERENCES `users` (`userid`) ON UPDATE CASCADE,
FOREIGN KEY (`sent_by`) REFERENCES `users` (`userid`) ON UPDATE CASCADE,
FOREIGN KEY (`message_id`) REFERENCES `messages` (`messageid`) ON DELETE CASCADE ON UPDATE CASCADE
)
My questions are
1) resolution of above mentioned error
2)What more fields should I include or remove for storing video details
You're using the wrong quote character on some of your column names. You should be using the backtick (`) everywhere.

It it possible to add a foreign key constraint to a composite key in mysql?

So I have 2 tables.
subject_schedule:
CREATE TABLE IF NOT EXISTS `subject_schedule` (
`subject` varchar(10) NOT NULL,
`schedule_id` int(11) NOT NULL,
`id` int(11) NOT NULL,
PRIMARY KEY (`subject`,`schedule_id`),
KEY `schedule_id` (`schedule_id`)
) ENGINE=InnoDB DEFAULT CHARSET=latin1;
and appointment:
CREATE TABLE IF NOT EXISTS `appointment` (
`work_plan` varchar(1000) DEFAULT NULL,
`date` date DEFAULT NULL,
`homework_given` varchar(1000) DEFAULT NULL,
`tutor_comments` varchar(1000) DEFAULT NULL,
`admin_comments` varchar(1000) DEFAULT NULL,
`id` int(11) NOT NULL AUTO_INCREMENT,
`schedule_id` int(11) NOT NULL,
`attended` tinyint(1) NOT NULL DEFAULT '1',
`arrival_time` time DEFAULT NULL,
`departure_time` time DEFAULT NULL,
`homework_completed` tinyint(1) NOT NULL DEFAULT '0',
`subject` varchar(10) NOT NULL,
PRIMARY KEY (`id`),
KEY `schedule_id` (`schedule_id`),
KEY `subject` (`subject`)
) ENGINE=InnoDB DEFAULT CHARSET=latin1 AUTO_INCREMENT=10004 ;
I want to create a foreign key which references the composite key in appointment. I have tried:
ALTER TABLE 'appointment'
ADD CONSTRAINT 'appointment_fk' FOREIGN KEY (`schedule_id`, `subject`)
REFERENCES 'subject_schedule' ('schedule_id', 'subject');
but it returns an error in PhpMyAdmin:
#1064 - You have an error in your SQL syntax; check the manual that corresponds to your MySQL server version for the right syntax to use
near ''appointment' ADD CONSTRAINT 'appointment_fk' FOREIGN KEY
(schedule_id, `su' at line 1
What am I doing wrong?
Is it better to just have an id as a primary key and reference that instead of using a composite key?
the columnNames shouldn't be wrap with single quotes because it will be converted to a string (not a column anymore)
ALTER TABLE appointment
ADD CONSTRAINT appointment_fk FOREIGN KEY (`schedule_id`, `subject`)
REFERENCES subject_schedule (schedule_id, subject);
SQLFiddle Demo

MySQL: Error Message Can't create table (errno: 150)

I have two tables, 'po' and 'receive'
CREATE TABLE `po` (
`PO_ID` bigint(20) NOT NULL,
`SERVICE_TYPE` bit(1) DEFAULT NULL,
`ENTRY_DATE` date NOT NULL,
`RECEIPT_DATE` date DEFAULT NULL,
`TURNOVER` date DEFAULT NULL,
`MOBILIZATION` date DEFAULT NULL,
`SITE_NAME` varchar(255) NOT NULL,
`SITE_CODE` varchar(45) DEFAULT NULL,
`SITE_TIN` varchar(45) DEFAULT NULL,
`SITE_ADDRESS` varchar(255) NOT NULL,
`COST` decimal(11,2) NOT NULL,
`XML` text,
PRIMARY KEY (`PO_ID`)
) ENGINE=InnoDB DEFAULT CHARSET=utf8$$
CREATE TABLE `receive` (
`RECEIPT_ID` varchar(100) NOT NULL,
`RECEIPT_DATE` date NOT NULL,
`PO_NUMBER` bigint(20) NOT NULL,
`SUPPLIER_ID` int(11) NOT NULL,
PRIMARY KEY (`RECEIPT_ID`)
) ENGINE=InnoDB DEFAULT CHARSET=utf8$$
I'm trying to connect two tables by defining a foreign key 'fk_po' on the table 'receive'
ALTER TABLE `fourthwave`.`receive`
ADD CONSTRAINT `fk_po`
FOREIGN KEY (`PO_NUMBER` )
REFERENCES `fourthwave`.`po` (`PO_ID` )
ON DELETE SET NULL
ON UPDATE SET NULL
, ADD INDEX `fk_po` (`PO_NUMBER` ASC)
However, the alter query above throws an error :
Error Code: 1005. Can't create table 'fourthwave.#sql-aec_11' (errno:150)
Am i getting this error because the field's names, 'PO_ID' and 'PO_NUMBER' on both tables are different?
Execute SHOW ENGINE INNODB STATUS statement after ALTER TABLE, and you will see the error message - 'You have defined a SET NULL condition though some of the
columns are defined as NOT NULL'.
ALTER TABLE `receive`
ADD CONSTRAINT `fk_po`
FOREIGN KEY (`PO_NUMBER` )
REFERENCES `po` (`PO_ID` )
ON DELETE SET NULL
ON UPDATE SET NULL
, ADD INDEX `fk_po` (`PO_NUMBER` ASC);
SHOW ENGINE INNODB STATUS;
You need an index on PO_NUMBER in the receive table. The field you are referencing in a foreign key always should be indexed.