Question

到目前为止，我已经写了一份精选陈述，以获取球队名称，主场比赛的平均得分以及他们对另一支球队的平均得分。

当他们离开时，我还有另一支球队，我在这里选择了离开的球队，他们离开时的平均得分和他们承认的平均值。

如何从选择查询中加入这两个表，以便获得一个包含团队名称，平均得分主场，平均失球主场，平均失球率和平均得分的表？

这是我的代码：

select home_team, avg(home_score_half + home_score_full) as avg_scored_home, 
       avg(away_score_half + away_score_full) as avg_conceded_home 
from matches 
group by home_team;

select away_team, avg(away_score_half + away_score_full) as avg_scored_away, 
       avg(home_score_half + home_score_full) as avg_conceded_away 
from matches 
group by away_team;

任何帮助将不胜感激。谢谢！

Answer 1

如果您希望结果加入（每个团队在同一行上），则可以将两个查询用作加入的子查询

select  t1.home_team
      , t1.avg_scored_home
      , t1.avg_conceded_home
      , t2.away_team
      , t2.avg_scored_away
      , t2.avg_conceded_away
from (
  select home_team
      , avg(home_score_half + home_score_full) as avg_scored_home
      , avg(away_score_half + away_score_full) as avg_conceded_home 
  from matches 
  group by home_team
) t1 
INNER JOIN (
  select away_team
    , avg(away_score_half + away_score_full) as avg_scored_away
    , avg(home_score_half + home_score_full) as avg_conceded_away 
  from matches group by away_team
) t2 ON t1.home_team = t2.away_team

无法从选择语句联接两个表

1 个答案: