Question

我使用lahman sabermetrics数据库学习MySQL

我试图查看哪些投手在整个数据中拥有最高的总体运行次数。击球表包含Home Runs（HR）列，而fielding表包含Position列（POS）

我已尝试过以下

SELECT playerID, SUM(HR) AS HR_SUM_TOTAL
FROM batting
GROUP BY playerID
WHERE (SELECT POS
       FROM fielding
       WHERE POS = "P")
ORDER BY HR_SUM_TOTAL DESC

有什么办法可以用嵌套选择做到这一点，还是更容易将POS列添加到击球表然后运行查询？

提前致谢

Answer 1

如果我正确理解你的问题，一种方法就是

SELECT b.playerID, SUM(b.HR) HR_SUM_TOTAL
  FROM batting b JOIN 
  (
      SELECT DISTINCT playerID
        FROM fielding
       WHERE POS = 'P'
  ) f ON b.playerID = f.playerID
 GROUP BY b.playerID
 ORDER BY HR_SUM_TOTAL DESC

或

SELECT playerID, SUM(HR) HR_SUM_TOTAL
  FROM batting 
 WHERE playerID IN
 (
     SELECT DISTINCT playerID
       FROM fielding
      WHERE POS = 'P'
 )
 GROUP BY playerID
 ORDER BY HR_SUM_TOTAL DESC

使用来自不同表的嵌套选择来形成条件

1 个答案: