Add a New Column

So far, we’ve become familiar with different queries like insert, delete, update, and select. We’ve also used several operators for our different requirements. Now, we’ll learn to add a new column to an existing table. Let’s suppose that we want to introduce a column with the name identity. We assume that each customer has a unique identity number, and we want to introduce this concept to our data model.

The alter table command

We execute the following alter table command to add the column:

alter table customers add column(identity varchar(32) not null);

Before we actually execute that command, let’s explore the elements that are used to compose the command.

Parts of the alter table command