MySQL - Counting rows and left join problem

Question

I have 2 tables, campaigns and campaign_codes:

campaigns: id, partner_id, status

campaign_codes: id, code, status

I want to get a count of all campaign_c

Answer 1

SELECT 
    c.id AS campaign_id, 
    COUNT(cc.id) AS code_count
FROM 
    campaigns c
LEFT JOIN campaign_codes cc on cc.campaign_id = c.id
    AND c.partner_id = 4
    AND cc.status = 0
GROUP BY c.id