Question

Title might be confusing, didn’t quite know how to put it. Here’s what i need to do. I have two tables, cronjobs and cronjob_seeds. I need to see if a cronjob exists before adding it to the database.

Consider these tables:

cronjobs:

-id-   -callback_model-         -callback_method-
1       movie_suggestion_model    fetch_similar_movies

cronjob_seeds:

-cronjob_id-   -seed-
1               seed1
1               seed2

Before adding a new cronjob, i need to see if the exact same cronjob exists in the database. I wrote the following query, but it doesn’t work if the cronjob has multiple seeds. It works good if it only has one seed, but every time a cronjob has multiple seeds it returns nothing.

SELECT `id`
FROM (`cronjobs`)
INNER JOIN `cronjob_seeds` ON `cronjob_seeds`.`cronjob_id` = `cronjobs`.`id`
WHERE `cronjobs`.`callback_model` = 'movie_suggestion_model'
    AND `cronjobs`.`callback_method` = 'fetch_similar_movies'
    AND `cronjob_seeds`.`seed` = '1'
    AND `cronjob_seeds`.`seed` = 10

Am i missing something? Should i be using another type of join?

And, off topic, but a seed is a parameter for the callback method, i just named it a little weird.

Answer 1

You should use IN clause

Change your query to:

SELECT `id`
FROM (`cronjobs`)
INNER JOIN `cronjob_seeds` ON `cronjob_seeds`.`cronjob_id` = `cronjobs`.`id`
WHERE `cronjobs`.`callback_model` = 'movie_suggestion_model'
    AND `cronjobs`.`callback_method` = 'fetch_similar_movies'
    AND `cronjob_seeds`.`seed` IN ('seed1', 'seed2')