Learn SQL using MySQL in One Day and Learn It Well

Chapter 10: Variables and Stored Routines

 

Congratulations on making it this far! We’ve covered most of the fundamental concepts in SQL.

 

In this chapter, we’ll cover something more advanced. Specifically, we’ll talk about stored routines.

 

However, before we do that, let’s first discuss variables. We need to understand variables before we can fully appreciate stored routines.

 

Variables

 

So what is a variable?

 

A variable is a name given to data that we need to store and use in our SQL statements.

 

For instance, suppose we want to get all information related to employee 1 from the employees and mentorships tables. We can do that as follows:

 

SELECT * FROM employees WHERE id = 1;

SELECT * FROM mentorships WHERE mentor_id = 1;

SELECT ...