mysql |那些关于第二大的事

SELECT
    (SELECT DISTINCT
            Salary
        FROM
            Employee
        ORDER BY Salary DESC
        LIMIT 1 OFFSET 1) AS SecondHighestSalary
;

SELECT
    IFNULL(
      (SELECT DISTINCT Salary
       FROM Employee
       ORDER BY Salary DESC
        LIMIT 1 OFFSET 1),
    NULL) AS SecondHighestSalary

SELECT MAX(Salary) AS SecondHighestSalary
     FROM Employee 
         WHERE Salary < (SELECT MAX(Salary) FROM Employee)

SELECT MAX(vcid) FROM msdtb1701 
     WHERE vcid < (SELECT MAX(vcid) FROM msdtb1701)

SELECT  MAX(vcid) FROM msdtb1701 
     WHERE vcid NOT IN (SELECT MAX(vcid) FROM msdtb1701)

SELECT vcuser ,vcid FROM msdtb1701 
     WHERE vcid=
            (SELECT MAX(vcid) FROM msdtb1701 WHERE vcid    
                 NOT IN (SELECT MAX(vcid) FROM msdtb1701))

SELECT MAX(vcid) FROM  msdtb1701 
     WHERE vcid < (SELECT  MAX(vcid) FROM msdtb1701 WHERE vcid 
              NOT IN (SELECT MAX(vcid) FROM msdtb1701))

SELECT vcid,vcuser FROM msdtb1701  ORDER BY vcid DESC LIMIT 3

CREATE FUNCTION getNthHighestSalary(N INT) RETURNS INT
BEGIN
DECLARE M INT;
SET M=N-1;
  RETURN (
      # Write your MySQL query statement below.
      SELECT DISTINCT Salary FROM Employee ORDER BY Salary DESC LIMIT M, 1
  );
END

select TOP N * from tablename where

SELECT * FROM TABLE1 WHERE ROWNUM<=N