MYSQL有多個選擇相應的條件不同的地方

Question

我想執行一個mysql語句，我有一個選擇不是where條件的一部分。 這是我的代碼：

SELECT oil.empid 
    , oil.mileage 
    , oil.`date` 
    , max(oil.mileage) AS expr1 

FROM 
    oil 
WHERE 
    oil.mileage < (SELECT max(oil.mileage) AS expr1 
       FROM 
        oil) 

GROUP BY 
    oil.empid 
ORDER BY 
    oil.mileage 

現在這個選擇的第二大里程，但我想要的是第二和最大行駛里程。我相信我只需要選擇WHERE以外的最大（里程），但我不知道該怎麼做。感謝您的幫助

編輯： 如果這些1497輸入的數據是

里程：100，100000，和200000

和EMPID 2000

里程：100，1500，5000

我想這樣的：

empid|2nd max | max 
1497 | 100000 | 200000 
2000 | 1500 | 5000 

Answer 1

您可以使用LIMIT與OFFSET在MySQL的ORDER BY子句中查找第二里程。通過這種方式，您可以不使用昂貴的GROUP BY。

（更新）由OP的澄清後：

SELECT oil.empid 
    , oil.mileage 
    , oil.date 
FROM 
     oil 
    JOIN 
     (SELECT DISTINCT empid 
      FROM oil 
     ) AS emp 
      ON oil.empid = emp.empid 
      AND oil.mileage >= 
       (SELECT mileage 
        FROM oil AS o 
        WHERE o.empid = emp.empid 
        ORDER BY mileage DESC 
        LIMIT 1 OFFSET 1 
       ) 
ORDER BY 
    oil.empid 
    , oil.mileage    --- ASC or DESC here, your choice 
; 

Answer 2

這可能是一個天真的反應，但爲什麼不只是這樣做：

SELECT oil.empid 
     , oil.mileage 
     , oil.`date` 
     , max(oil.mileage) as expr1 
FROM oil 
GROUP BY oil.empid, oil.`date` 
ORDER BY oil.mileage DESC 
LIMIT 2 

UPDATE
鑑於OP的更新很顯然，我們需要的那種完全不同的查詢，像這樣：

SELECT outer.empid 
     , (SELECT first.mileage 
      FROM oil as first 
      WHERE first.empid = outer.empid 
      ORDER BY first.mileage DESC 
      LIMIT 1) AS max 
     , (SELECT second.mileage 
      FROM oil as second 
      WHERE second.empid = outer.empid 
      ORDER BY second.mileage DESC 
      LIMIT 1 
      OFFSET 1) as 2nd_max 
FROM oil as outer