Left join with multiple status - mysql

Question

Lets say i have two stores. Store A(22) and Store B(21). This is the query to fetch the things that matched with the Store ID:
SELECT c . * , s.s_name, s.logo, s.s_slug, cm.c_code, cm.c_shorturl, cm.c_shorturl_id
FROM ci_cptbl c
LEFT JOIN ci_stores s ON s.store_id = c.store_id
LEFT JOIN ci_cptbl_mapper cm ON cm.c_id = c._id
WHERE c.coupon_id <> ''
AND c.store_id in ('22', '21')
AND s.s_status = '1'
AND c.c_status = '1'
AND DATE( c.c_end_date ) >= '2014-10-04'
ORDER BY c.c_id DESC
ci_cptbl Has the collection of product including the store_id. And ci_stores holds the store name, etc.. including s_status(0, 1).
CREATE TABLE `ci_stores` (
`store_id` int(10) NOT NULL AUTO_INCREMENT,
`cat_id` int(10) NOT NULL,
`s_name` varchar(255) NOT NULL,
`s_slug` varchar(255) NOT NULL,
`logo` varchar(255) NOT NULL,
`display_name` varchar(255) NOT NULL,
`s_description` text NOT NULL,
`network_id` int(10) NOT NULL,
`s_status` tinyint(1) NOT NULL DEFAULT '0',
`merged_stores` text NOT NULL,
`stat` bigint(20) NOT NULL,
PRIMARY KEY (`store_id`),
KEY `network_id` (`network_id`),
KEY `cat_id` (`cat_id`),
FULLTEXT KEY `display_name` (`display_name`)
) ENGINE=MyISAM AUTO_INCREMENT=127 DEFAULT CHARSET=utf8
Now condition is i have only first store id( 22 ) enabled and rest is disabled (21, .....) in my stores table and my AND s.s_status = '1' statement works only if all the stores are enabled but i want all stores including disabled.
BUT FIRST STORE ID MUST BE ENABLED

Answer 1

You could try changing you condition to test on store_id and enabled
(c.c_status = '1' or c.store_id <> '22')
so:
SELECT c . * , s.s_name, s.logo, s.s_slug, cm.c_code, cm.c_shorturl, cm.c_shorturl_id
FROM ci_cptbl c
LEFT JOIN ci_stores s ON s.store_id = c.store_id
LEFT JOIN ci_cptbl_mapper cm ON cm.c_id = c._id
WHERE c.coupon_id <> ''
AND c.store_id in ('22', '21')
AND s.s_status = '1'
AND (c.c_status = '1' or c.store_id <> '22')
AND DATE( c.c_end_date ) >= '2014-10-04'
ORDER BY c.c_id DESC

Answer 2

You need to move your "AND s.s_status = 1" clause to the LEFT JOIN part of your query. When you move it to the WHERE clause, it forces to an implied INNER JOIN and thus leaving out of you result set.
LEFT JOIN ci_stores s
ON c.store_id = s.store_id
AND s.s_status = '1'

Answer 3

FROM ci_cptbl c
LEFT JOIN ci_stores s ON s.store_id = c.store_id
The purpose of that LEFT JOIN is to allow unmatched records in the "joined to" table to be listed in the results
e.g. if there is a store 657 in ci_cptbl but no such store in ci_stores 657 would still be listed
However, using the WHERE clause:
if we then ALSO insist EVERY row has s.s_status = '1'
then store 657 would NOT be listed (how can it? it does not exist in ci_stores so ci_stores.s_status has to be NULL and can never ever be equal to 1
So; when using any outer join such as a LEFT OUTER JOIN you have to be very careful how you reference those tables in the WHERE clause. In many cases, such as here, it is better to move the additional condition(s) to the JOIN like this:
FROM ci_cptbl c
LEFT JOIN ci_stores s ON s.store_id = c.store_id
AND s.s_status = '1'