7. Further SQL

The syllabus is mainly concerned with the fundamental sql queries of CREATE, INSERT, UPDATE, SELECT and DELETE

And the examples demonstrate their use with a single table.

But a full relational database is usually comprised of several related tables. SQL supports the extraction of records based on the values across more than one table.

A key command is the JOIN. This allows records selection, insertion and updates to occur based on criteria across a number of tables. If you wish to find out more about sql then we recommend you explore the uses of this command as well