Question

It’s a question I got this afternoon:

There a table contains ID, Name, and Salary of Employees, get names of the second-highest salary employees, in SQL Server

Here’s my answer, I just wrote it in paper and not sure that it’s perfectly valid, but it seems to work:

SELECT Name FROM Employees WHERE Salary = 
( SELECT DISTINCT TOP (1) Salary FROM Employees WHERE Salary NOT IN
 (SELECT DISTINCT TOP (1) Salary FROM Employees ORDER BY Salary DESCENDING)
ORDER BY Salary DESCENDING)

I think it’s ugly, but it’s the only solution come to my mind.

Can you suggest me a better query?

Thank you very much.

Answer 1

To get the names of the employees with the 2nd highest distinct salary amount you can use.

;WITH T AS
(
SELECT *,
       DENSE_RANK() OVER (ORDER BY Salary Desc) AS Rnk
FROM Employees
)
SELECT Name
FROM T
WHERE Rnk=2;

If Salary is indexed the following may well be more efficient though especially if there are many employees.

SELECT Name
FROM   Employees
WHERE  Salary = (SELECT MIN(Salary)
                 FROM   (SELECT DISTINCT TOP (2) Salary
                         FROM   Employees
                         ORDER  BY Salary DESC) T);

Test Script

CREATE TABLE Employees
  (
     Name   VARCHAR(50),
     Salary FLOAT
  )

INSERT INTO Employees
SELECT TOP 1000000 s1.name,
                   abs(checksum(newid()))
FROM   sysobjects s1,
       sysobjects s2

CREATE NONCLUSTERED INDEX ix
  ON Employees(Salary)

SELECT Name
FROM   Employees
WHERE  Salary = (SELECT MIN(Salary)
                 FROM   (SELECT DISTINCT TOP (2) Salary
                         FROM   Employees
                         ORDER  BY Salary DESC) T);

WITH T
     AS (SELECT *,
                DENSE_RANK() OVER (ORDER BY Salary DESC) AS Rnk
         FROM   Employees)
SELECT Name
FROM   T
WHERE  Rnk = 2;

SELECT Name
FROM   Employees
WHERE  Salary = (SELECT DISTINCT TOP (1) Salary
                 FROM   Employees
                 WHERE  Salary NOT IN (SELECT DISTINCT TOP (1) Salary
                                       FROM   Employees
                                       ORDER  BY Salary DESC)
                 ORDER  BY Salary DESC)

SELECT Name
FROM   Employees
WHERE  Salary = (SELECT TOP 1 Salary
                 FROM   (SELECT TOP 2 Salary
                         FROM   Employees
                         ORDER  BY Salary DESC) sel
                 ORDER  BY Salary ASC)