Mysql CASE WHEN JOIN Statement Error

Question

Mysql Query:

SELECT *
FROM `pet_info` LEFT JOIN
     `lostpets`
     ON `pet_info`.`id` = `lostpets`.`petid` LEFT JOIN
     `pet_images`
     ON `pet_info`.`id`          


        

Answer 1

I think you intend:

SELECT *
FROM `pet_info` LEFT JOIN
     `lostpets`
     ON `pet_info`.`id` = `lostpets`.`petid` LEFT JOIN
     `pet_images`
     ON `pet_info`.`id` = `pet_images`.`petid` LEFT JOIN
     `cat_breeds`
     ON `cat_breeds`.`id` = `pet_info`.`pet_breed` AND
        `pet_info`.`pet_cat` = 2 LEFT JOIN
     `dog_breeds`
     ON `dog_breeds`.`id` = `pet_info`.`pet_breed` AND
        `pet_info`.`pet_cat` = 1
WHERE `pet_info`.`pet_user_id` = 581;

Notes:

• With a query like this, you should not use SELECT *, you should explicitly choose the columns you want. The different tables have columns with the same name.
• You should use column aliases. I didn't put these into the query, but they are a good idea.
• In a real query, you would have expressions in the SELECT to combine columns from cat_breeds and dog_breeds, such as COALESCE(cat_breeds.col1, dog_breeds.col1) as col1.