Question

我有一个很多板球碗的数据库。架构是：

Player(PlayerID, Initials, Surname)
 - Stores all the players
Bowl(BowlID, Striker, Non-Striker, Bowler, Runs)
 - Stores info for every ball
Team(TeamID, name)
 - Stores all the teams
SquadPlayer(TeamID, PlayerID, MatchID)
 - Stores a record of who was playing at each match and for which team

我试图找到英格兰队每位球员得分的数量。（我使用的是openoffice风格的HSQL）

SELECT "Player"."Initials", "Player"."Surname", COUNT ("Bowl"."Striker") AS "No. Sixes"
FROM "Bowl", "Player", "Player" AS "Bowler"
WHERE "Bowl"."Striker" = "Player"."PlayerID"
AND "Bowl"."Bowler" = "Bowler"."PlayerID"
AND "Bowl"."Striker" IN (
    SELECT DISTINCT "Player"."PlayerID" 
    FROM "Player", "Team", "SquadPlayer"
    WHERE "Player"."PlayerID" = "SquadPlayer"."PlayerID" 
    AND "Team"."TeamID" = "SquadPlayer"."TeamID" 
    AND "Team"."Name" = 'England' )
AND "Bowl"."Runs" = '6'
GROUP BY "Bowl"."Striker"

这是我正在尝试运行的SQL，但它不起作用。如果我省略SELECT部分中的前两列（Player.Initials和Player.Surname），它可以正常工作，但它不是很有用，因为我无法计算出所有六个人的WHO分数。

我通过java运行它，我得到了例外：

java.sql.SQLException: Not in aggregate function or group by clause

那么为什么这不起作用？如何在旁边显示名称？

Answer 1

如果select子句中有count（或任何聚合函数），则select-clause中的所有未聚合列也必须出现在group-by子句中。

让你的组子句看起来像这样：

GROUP BY "Bowl"."Striker", "Player"."Initials", "Player"."Surname"

它应该有用..

Answer 2

SELECT子句中的任何字段都需要使用聚合函数或包含在GROUP BY子句中，这就是为什么会出现此错误。因此，您必须在"Player"."Initials", "Player"."Surname"子句中包含GROUP BY或使用聚合函数。类似的东西：

SELECT "Player"."Initials", "Player"."Surname", 
      COUNT ("Bowl"."Striker") AS "No. Sixes"
FROM "Bowl", "Player", "Player" AS "Bowler"
WHERE "Bowl"."Striker" = "Player"."PlayerID"
AND "Bowl"."Bowler" = "Bowler"."PlayerID"
AND "Bowl"."Striker" IN (
    SELECT DISTINCT "Player"."PlayerID" 
    FROM "Player", "Team", "SquadPlayer"
    WHERE "Player"."PlayerID" = "SquadPlayer"."PlayerID" 
    AND "Team"."TeamID" = "SquadPlayer"."TeamID" 
    AND "Team"."Name" = 'England' )
AND "Bowl"."Runs" = '6'
GROUP BY "Bowl"."Striker", "Player"."Initials", "Player"."Surname"

Answer 3

您的论坛应该是您未汇总的列。

SELECT "Player"."Initials", "Player"."Surname", COUNT ("Bowl"."Striker") AS "No. Sixes"
FROM "Bowl", "Player", "Player" AS "Bowler"
WHERE "Bowl"."Striker" = "Player"."PlayerID"
AND "Bowl"."Bowler" = "Bowler"."PlayerID"
AND "Bowl"."Striker" IN (
    SELECT DISTINCT "Player"."PlayerID" 
    FROM "Player", "Team", "SquadPlayer"
    WHERE "Player"."PlayerID" = "SquadPlayer"."PlayerID" 
    AND "Team"."TeamID" = "SquadPlayer"."TeamID" 
    AND "Team"."Name" = 'England' )
AND "Bowl"."Runs" = '6'
GROUP BY "Player"."Initials", "Player"."Surname"

Answer 4

如果在查询中使用count，sum等（聚合函数），则检索到的不在聚合中的所有列都必须在group by子句中。

将您的group by子句更改为

GROUP BY  "Player"."Initials", "Player"."Surname"

SQL COUNT显示的不仅仅是计数？

4 个答案: