Read this SQL tutorial to learn when to use SELECT, JOIN, subselects and UNION to access multiple ... when many tables are involved. There are several types of JOIN — LEFT, RIGHT, and FULL ...

When you execute a query using the LEFT JOIN syntax, SQL does two things: It returns all of the records from both tables that contain matching values, as defined by the ON clause. It also returns ...

This means that SQL combines each row from the first table with ... joins can be performed on up to 16 tables at a time, whereas outer joins (left, right, full) work on only two tables at a time. If ...

The left join updates all rows in table A. Inner join only updates rows in table A where there is a matching ID in table B. You're working with different row sets. Now if you said something like: ...