Why do you DECLARE a variable in SQL?

What is the use of DECLARE in SQL?

The DECLARE statement initializes a variable by assigning it a name and a data type. The variable name must start with the @ sign. In this example, the data type of the @model_year variable is SMALLINT . By default, when a variable is declared, its value is set to NULL .

How do you DECLARE a variable number in SQL?

For example: DECLARE @site_value INT = 10; This variable declaration example would declare a variable called @site_value that is an INT datatype. It would then set the value of the @techonthenet variable to the integer value fo 10.

Why do we use table variables?

The table variable is a special type of the local variable that helps to store data temporarily, similar to the temp table in SQL Server. In fact, the table variable provides all the properties of the local variable, but the local variables have some limitations, unlike temp or regular tables.

How do you write a variable in SQL query?

The syntax for assigning a value to a SQL variable within a SELECT query is @ var_name := value , where var_name is the variable name and value is a value that you're retrieving. The variable may be used in subsequent queries wherever an expression is allowed, such as in a WHERE clause or in an INSERT statement.