Question

This is a mysql question. I have two tables one called forms and the other records. The records are a record for each form. I can have multiple records associate with a form id. However not all forms have a record associated with. I want to find all forms that do not have a record.

The best I could do is this

SELECT * 
FROM forms
JOIN records WHERE forms.form_id != records.form_id

However I end up with a million plus records and I know that is not correct.

Answer 1

Try a LEFT OUTER JOIN:

SELECT * FROM forms 
LEFT OUTER JOIN records
ON forms.form_id = records.form_id
WHERE records.form_id IS null