Specifies a subquery to test for the existence of rows.
- Is a restricted SELECT statement.
Returns TRUE if a subquery contains any rows.
The following example finds, from the Orders table, all the orders with Washington as the Shipping Region for Employees who are listed in the Employees table in the Northwind database.
SELECT * FROM Orders WHERE ShipRegion = 'WA' AND EXISTS (SELECT EmployeeID FROM Employees AS Emp WHERE Emp.EmployeeID = Orders.EmployeeID)