You should consider using the more modern `INNER JOIN` syntax. Using `table1, table2, table3` often leads to cartesian product. It's still possible with `table1 INNER JOIN table2 ON ... INNER JOIN table3 ON ...` however it is far less likely when you logically separate the join criteria from the filter criteria. While the following post deals with SQL Server specifically, the concept is essentially the same: - https://sqlblog.org/2009/10/08/bad-habits-to-kick-using-old-style-joins