It's time to talk about the Data Manipulation Language (DML). Don't worry; it's not a new programming language—just a fancy name to a subset of SQL instructions. I'll start with the SELECT statement.
Written by Rafael Victória-Pereira
Instead of starting by explaining how to build an SQL database from the ground up, let's start by discussing the things that you can use to query and change data in your DDS-defined physical files: a set of SQL instructions used to manipulate data, commonly referred to as the Data Manipulation Language, or DML. Entire books have been written about the DML; my objective here is to provide a helicopter view of the main DML instructions, accompanied by examples whenever possible.
Let's visit (or for some readers, re-visit) one of the most-used SQL instructions: the SELECT.