SQL Exists Keyword
Table Of Contents:
- What Is SQL Exists Keyword?
- Syntax Of SQL Exists.
- Examples Of SQL Exists.
(1) What Is SQL Exists Keyword?
- The EXISTS operator is used to look for the existence of a row in a given table that satisfies a set of criteria.
- It is a Boolean operator that compares the result of the subquery to an existing record and returns true or false.
- The returned value is true, if the subquery fetches single or multiple records and false if no record is matched.
- It is used in the combination of the subquery and checks whether a row is returned through this subquery or not.
(2) Syntax Of SQL Exists Keyword.
SELECT column_name(s)
FROM table_name
WHERE EXISTS
(SELECT column_name FROM table_name WHERE condition);(3) Examples Of SQL Exists Keyword.
Products Table:
Suppliers Table:
Example-1:
SELECT SupplierName
FROM Suppliers
WHERE EXISTS (SELECT ProductName FROM Products WHERE Products.SupplierID = Suppliers.supplierID AND Price < 20);
Example-2:
SELECT SupplierName
FROM Suppliers
WHERE EXISTS (SELECT ProductName FROM Products WHERE Products.SupplierID = Suppliers.supplierID AND Price = 22);
