If I replace JOIN with FULL OUTER JOIN, you'll get what you describe. It was just an quick example, but you are right. There are also things to say about what

If I replace JOIN with FULL OUTER JOIN, you'll get what you describe. It was just an quick example, but you are right. There are also things to say about what happens if either table has duplicate vegetable_id:s. At some point it is assumed that you have processed it in such a way that the table is well formed for the purpose.