CODEWITHSUNDEEP
mysqljoinsql-delete
ven
ven

Reputation: 405

How to delete mysql rows using join?

I have three tables:

"products" -         contains products
"location" -         store location
"product_orders" -   joins data from products and location

SQL DUMP:

--
-- Table structure for table `location`
--

CREATE TABLE IF NOT EXISTS `location` (
  `id` int(11) NOT NULL AUTO_INCREMENT,
  `name` varchar(255) NOT NULL,
  PRIMARY KEY (`id`)
) ENGINE=MyISAM  DEFAULT CHARSET=utf8 AUTO_INCREMENT=77 ;

--
-- Dumping data for table `location`
--

INSERT INTO `location` (`id`, `name`) VALUES
(1, 'Miami'),
(2, 'Denver');

-- --------------------------------------------------------

--
-- Table structure for table `products`
--

CREATE TABLE IF NOT EXISTS `products` (
  `id` int(11) NOT NULL AUTO_INCREMENT,
  `type` varchar(255) NOT NULL DEFAULT '',
  `product` text NOT NULL,
  PRIMARY KEY (`id`)
) ENGINE=MyISAM  DEFAULT CHARSET=utf8 AUTO_INCREMENT=6014552 ;

--
-- Dumping data for table `products`
--

INSERT INTO `products` (`id`, `type`, `product`) VALUES
(1, 'shirt', 'red shirt'),
(2, 'shirt', 'red shirt'),
(3, 'pants', 'blue pants'),
(4, 'pants', 'blue pants');

-- --------------------------------------------------------

--
-- Table structure for table `product_orders`
--

CREATE TABLE IF NOT EXISTS `product_orders` (
  `product_id` int(11) NOT NULL,
  `location_id` int(11) NOT NULL,
  `status` varchar(255) NOT NULL,
  PRIMARY KEY (`product_id`,`location_id`),
  KEY `ix_product_orders` (`location_id`),
  KEY `ix_product_orders_1` (`product_id`)
) ENGINE=MyISAM DEFAULT CHARSET=latin1;

--
-- Dumping data for table `product_orders`
--

INSERT INTO `product_orders` (`product_id`, `location_id`, `status`) VALUES
(1, 1, 'sold'),
(2, 2, 'sold'),
(1, 2, 'available'),
(2, 1, 'sold');

If I want to select all sold products from store 'miami - this query works:

SELECT * FROM `products`
INNER JOIN `product_orders`
ON `product_orders`.`product_id`= `products`.`id`
WHERE `product_orders`.`location_id` = '1'
AND
status = 'sold'

How would you rewrite to delete all sold products from the miami store? My query is not working:

 DELETE `products` FROM `products`
INNER JOIN `product_orders`
ON `product_orders`.`location_id` = `products`.`id`
WHERE `product_orders`.`location_id` = '2'
AND
status = 'sold'

Upvotes: 0

Views: 92

Answers (3)

bonCodigo
bonCodigo

Reputation: 14361

I am not sure how you have set foreign keys in your tables. But looking at it with the most primary assumptions, product table holds products data and location holds location data. In your common table product orders you are having one foreign key to products table by product id and one another relation to location table by location.

So to back my comment, I am posting the following query. It is your query with a change to a field that I ASSUME WAS A TYPO....in your query. :-) Again as foampile said, I might be doing it with consistency... 

 DELETE FROM `products`
 INNER JOIN `products_orders` 
 ON `products_orders`.`product_id` = `products`.`id`
 WHERE `products_orders`.`location` = 'miami' 
 AND `products_orders`.status = 'sold'
 ;

Upvotes: 1

amphibient
amphibient

Reputation: 31368

DELETE FROM products WHERE id IN (SELECT location_id FROM products_orders WHERE location = 'miami' AND status = 'sold');

Upvotes: 1

Muthu Kumaran
Muthu Kumaran

Reputation: 17930

Try this one,

DELETE `products` FROM `products` INNER JOIN `products_orders` 
ON `products_orders`.`location_id` = `products`.`id` 
WHERE `products_orders`.`location` = 'miami' 
AND
status = 'sold'

OR

DELETE prod FROM `products` AS prod INNER JOIN `products_orders` 
ON `products_orders`.`location_id` = `products`.`id` 
WHERE `products_orders`.`location` = 'miami' 
AND
status = 'sold'

Upvotes: 1

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