Variables in MySQL

In MySQL, variables are used to store temporary values that can be used throughout a query or stored procedure. Variables can be assigned a value using the SET statement, and their values can be retrieved using the SELECT statement. In this tutorial, we'll discuss how to define and use variables in MySQL.

Syntax

The syntax for defining a variable in MySQL is as follows:

SET @variable = value;

Here, "@" is used to declare a variable, "variable" is the name of the variable, and "value" is the value that we want to assign to the variable.

Example

Let's say we want to store a value of 10 in a variable called "num". Here's how we can do it:

SET @num = 10;

Now, we can use this variable in our SQL queries:

SELECT @num; -- Output: 10

Output

When we run the SELECT statement above, the output will be:

+------+
| @num |
+------+
|  10  |
+------+

This is because we assigned the value 10 to the "num" variable using the SET statement, and then retrieved its value using the SELECT statement.

Explanation

In the example above, we declared a variable called "num" and assigned a value of 10 to it using the SET statement. We then retrieved its value using the SELECT statement.

Use

Variables are useful for storing temporary values that can be used throughout a query or stored procedure. They can be used to store data that is used repeatedly in the query, or to perform calculations on data that is retrieved from the database.

Important Points

• Variables in MySQL start with the "@" symbol.
• Variables can be assigned a value using the SET statement.
• Variables can be used in SQL statements using the "@" symbol.

Summary

In this tutorial, we discussed how to define and use variables in MySQL. We covered the syntax, example, output, explanation, use, and important points of variables in MySQL. With this knowledge, you can now use variables in your MySQL queries to store temporary values and perform calculations on data that is retrieved from the database.