User-Defined Variables

What is an example of a user variable?

A user variable is a variable that you define and use in your SQL session to store temporary values. For example, if you want to store the number 10 in a variable, you can do it like this:

SET @myVar = 10;

Now, @myVar holds the value 10, and you can use it in your queries:

SELECT @myVar;

— This will return 10

What is a user-defined variable in SQL?

A user-defined variable in SQL is a variable that you, the user, create and use within a session. These variables are used to store temporary values that can be reused in subsequent SQL statements within the same session. They are not stored permanently in the database.

For example:

SET @totalSales = 1000;

Here, @totalSales is a user-defined variable that stores the value 1000.

User-Defined Variables in are a way to store temporary values that can be used within a session. These variables are unique to a session and are not persistent across multiple sessions. They can be very useful for storing intermediate results or values that you want to reuse within a single session.

MySQL also supports the concept of User-defined variables, which allows passing of a value from one statement to another. A user-defined variable in MySQL is written as @var_name where, var_name is the name of the variable and can consist of alphanumeric characters, ., _, and $.