Now, let’s interpret the above syntax. Firstly, if we want to use a variable in SQL Server, we have to declare it. The DECLARE statement is used to declare a variable in SQL Server. In the second step, we have to specify the name of the variable. Local variable names have to start with an at (@) sign because this rule is a syntax necessity. Finally, we defined the data type of the variable. The value argument which is indicated in the syntax is an optional parameter that helps to assign an initial value to a variable during the declaration. On the other hand, we can assign or replace the value of the variable on the next steps of the batch. If we don’t make any initial value assigned to a variable, it is initialized as NULL. The following example will declare a variable whose name will be @VarValue and the data type will be varchar. At the same time, we will assign an initial value which is ‘Save Our Planet’:
DECLARE @ TestVariable AS VARCHAR ( 100 ) = 'Save Our Planet'
