Question

I have 3 separate tables: ‘object’ (id, name, model_id), ‘object_model’ (id, name, type_id) and ‘object_type’ (id, name).

How can I properly join these three to get the appropriate names from all the tables?

I’m trying to join by doing the following:

SELECT object.id AS id, object.name AS name, object_model.name AS model_name, object_type.name AS type_name 
FROM object 
LEFT JOIN object_model ON object_model.id = object.model_id 
LEFT JOIN object_type ON object_type.id = object.model_type_id

But get the error:

“Unknown column ‘object.model_type_id’ in ‘on clause'”

Answer 1

Your column is called object_model.type_id. You have the dot and underscore in the wrong places.

LEFT JOIN object_type ON object_type.id = object_model.type_id

Otherwise, your query looks like it will do what you want it to do.