Question

Imagine two tables that both have a common ID field that joins two tables together.

Lets call them Table1 and Table2.

Table1 joins Table2 on the field ID.

How do I get all results on Table2 that has an ID that

Answer 1

guessing you need one of these

SELECT * FROM table1 JOIN LEFT table2 ON table1.id=table2.id WHERE table2.id IS NULL

or

SELECT * FROM table1 JOIN LEFT table2 ON table1.id=table2.id WHERE table2.id IS NOT NULL