Combine conditions with AND in Mysql ON clause - mysql

Question

I have the following query, that I use to filter rows based on software_id and level.
I've put the conditions in the ON-Clause since I still want rows returned, where there are no corresponding rows in the JobadvertsSoftware Table.
SELECT `Jobadvert`.`id` FROM `jobadverts` AS `Jobadvert`
LEFT JOIN `users` AS `User` ON (`Jobadvert`.`user_id` = `User`.`id`)
LEFT JOIN `jobadverts_softwares` AS `JobadvertsSoftware_0` ON
(`Jobadvert`.`id` = 'JobadvertsSoftware_0.jobadvert_id' AND
(`JobadvertsSoftware_0`.`software_id` = '32' AND
`JobadvertsSoftware_0`.`level` IN ('1', 4)))
WHERE `Jobadvert`.`active` = 1 AND `User`.`premium` = '1' AND
Jobadvert`.`department_id` = (5)
GROUP BY `Jobadvert`.`id`
The problem is that it also returns JobadvertsSoftware-rows where level is e.g. 2
Again, if I put that in the WHERE clause it will filter out the rows where there are not JobadvertsSoftware which it shouldn't do.
How can I tell MySQL to return all rows of Jobadvert, where the given software_id AND the level matches or are NULL?

Answer 1

Try this:
SELECT `Jobadvert`.`id`, `JobadvertsSoftware_0`.`level`
FROM `jobadverts` AS `Jobadvert`
LEFT JOIN `users` AS `User` ON (`Jobadvert`.`user_id` = `User`.`id`)
INNER JOIN `jobadverts_softwares` AS `JobadvertsSoftware_0` ON
(`Jobadvert`.`id` = 'JobadvertsSoftware_0.jobadvert_id' AND
(`JobadvertsSoftware_0`.`software_id` = '32' AND
`JobadvertsSoftware_0`.`level` IN ('1', 4)))
WHERE `Jobadvert`.`active` = 1 AND `User`.`premium` = '1' AND
Jobadvert`.`department_id` = (5)
GROUP BY `Jobadvert`.`id`
Saludos!

Answer 2

Try this( it's a bit unclear if some fields are numeric on string, it might be corrected):
SELECT distinct(`Jobadvert`.`id`) FROM `jobadverts` AS `Jobadvert`
LEFT JOIN `users` AS `User` ON (`Jobadvert`.`user_id` = `User`.`id`)
LEFT JOIN `jobadverts_softwares` AS `JobadvertsSoftware_0`
ON `Jobadvert`.`id` = `JobadvertsSoftware_0.jobadvert_id`
WHERE
`Jobadvert`.`active` = 1
AND `User`.`premium` = '1'
AND Jobadvert`.`department_id` = (5)
AND JobadvertsSoftware_0`.`software_id` = '32'
AND (`JobadvertsSoftware_0`.`level` IN (1, 4) OR `JobadvertsSoftware_0`.`level` is NULL)

Answer 3

Assuming the level parameters in your ON clause is not needed for the join you can do a nested SELECT on your Software table to clear out the data you do not need first:
SELECT * FROM jobadverts_softwares
WHERE
(`software_id` = 32 OR `software_id` IS NULL) --Select all software_id that are 32 or null
AND
`level` IN (1, 4)
Then you can incorporate this as a nested statement in your main SQL query so you only join on the data which is filtered in your LEFT JOIN but keep any null values that you needed:
SELECT `Jobadvert`.`id`
FROM `jobadverts` AS `Jobadvert`
LEFT JOIN `users` AS `User`
ON `Jobadvert`.`user_id` = `User`.`id`
LEFT JOIN
( --Software Subquery
SELECT `jobadvert_id`, `level` FROM jobadverts_softwares
WHERE
(`software_id` = 32 OR `software_id` IS NULL) --Select all software_id that are 32 or null
AND
`level` IN (1, 4)
) AS `software_subquery`
ON `Jobadvert`.`id` = `software_subquery`.`jobadvert_id`
WHERE
`Jobadvert`.`active` = 1
AND
`User`.`premium` = '1'
AND
`Jobadvert`.`department_id` = 5
ORDER BY `Jobadvert`.`id` --Changed GROUP BY to ORDER BY as not needed
This is untested but try it out and see if this will help.

Answer 4

Try this:
SELECT j.id
FROM jobadverts j
LEFT JOIN User u ON (j.user_id = u.id)
LEFT JOIN jobadverts_softwares AS js ON
(j.id = js.jobadvert_id)
WHERE j.active = 1
AND u.premium = '1'
AND j.department_id = (5)
AND js.software_id` = '32'
AND js.level IN ('1', 4)))
You won't need a GROUP BY unless summing data in some way.