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Single row subqueries

Single-row subqueries in SQL return only one row as the result and are typically used within a WHERE clause or as a column expression.

 

Consider a table named Employees with columns EmployeeID, EmployeeName, and Salary. We want to retrieve the name of the employee whose salary is the highest.

SELECT EmployeeName FROM Employees WHERE Salary = (SELECT MAX(Salary) FROM Employees);

 

In this example, the subquery (SELECT MAX(Salary) FROM Employees) returns the highest salary from the Employees table. The outer query then retrieves the EmployeeName where the Salary matches the highest salary found by the subquery. This query will return the name of the employee with the highest salary.


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