I’ve merely checked to make sure the relevant column from table1 exists in table3.
Not all database manufacturers follow this standard, and many have made enhancements that can yield unexpected results.
If you’re uncertain about support for these concepts in your database, please refer to your manufacturer’s documentation.
The WHERE clause tells the database which fields to correlate, and it returns results as if the tables listed were combined into a single table based on the provided conditions.
It’s worth noting that your conditions for comparison don’t have to be the same columns you return as your result set.
A simple SELECT statement is the most basic way to query multiple tables.