How to use With Clause to Declare Variable in SQL In SQL
The WITH clause in SQL that allows defining temporary result sets within a query. Variables can be declared and assigned values within the WITH clause.
Query:
WITH Customers AS (
SELECT "GFG" AS name
)
SELECT * FROM Customers;
Output:
Explanation: The output shows a virtual table named “Customers” created using a Common Table Expression (CTE). It consists of a single column labeled “name”, containing the value “GFG“. The SELECT statement retrieves all rows from this “Customers” table, displaying the single row with “GFG” as the name.
How to Declare a Variable in SQL?
Variables in SQL are a fundamental step towards building efficient and powerful database applications. It enhances the flexibility and efficiency of our database queries.
Understanding how to declare variables in SQL is very important for writing scalable code. Variables act as placeholders for data, which enable us to manipulate and store information within our SQL programs.
Here, we’ll explore the various methods and best practices for declaring variables in SQL, along with the syntax and examples, that help us write more dynamic and effective queries.