What is the method for defining variables in MySQL?

In MySQL, you can define variables using the SET statement. The syntax is as follows:

SET @变量名 = 值;

For example, to define a variable named count and set it to 10, you can use the following statement:

SET @count = 10;

Variable names must begin with the @ symbol and can be any valid identifier. The value of a variable can be any valid MySQL expression, such as constants, column names, or function calls.