Question

我正在尝试创建一个用于标准化“运动器材”的视图，但是我在灯具表中同时具有主队和客队的ID。在尝试对它们进行标准化时，如何获得相关团队的团队名称？

select cast(`f`.`datetime` as date) AS `date`
     , cast(`f`.`datetime` as time) AS `time`
     , (select `t`.`name` 
        from (`fixturef_testing`.`teams` `t` 
        join `fixturef_testing`.`fixtures` `f` 
          on((`f`.`hometeamid` = `t`.`id`))) 
        where (`t`.`id` = `f`.`hometeamid`)) AS `hometeam`
     , (select `t`.`name` 
        from (`fixturef_testing`.`teams` `t` 
        join `fixturef_testing`.`fixtures` `f` 
          on((`f`.`awayteamid` = `t`.`id`))) 
        where (`t`.`id` = `f`.`awayteamid`)) AS `awayteam`
     , `u`.`name` AS `referee`,`c`.`name` AS `competition` 
from ((`fixturef_testing`.`fixtures` `f` 
left join `fixturef_testing`.`users` `u` 
  on((`u`.`id` = `f`.`refereeid`))) 
left join `fixturef_testing`.`competition` `c` 
  on((`c`.`id` = `f`.`competitionid`))) 
where (`f`.`active` = 1)

固定装置有hometeamid和awayteamid 团队有ID和名称

我尝试了一个子查询，但是它返回了多个结果。

任何帮助/建议都值得赞赏。

Teams Fixtures

Answer 1

您需要两次加入团队，一次加入主队，一次离开。

这样想：对于同一张表，每个外键都需要另一个联接。

尽管我不确定为什么您要对fixff_test进行多次联接，然后为用户一次进行联接，然后为完成进行一次联接...

此外，我也不喜欢把所有东西都放在后面。我宁愿仅在有保留/关键字以使其更具可读性时使用它。

SELECT cast(f.`datetime` as date) AS `date`
     , cast(f.`datetime` as time) AS `time`
     , HT.Name hometeam
     , AT.Name awayteam
     , u.name AS referee
     , c.name AS competition
FROM fixturef_testing.fixtures f
--Are the next 2 joins really needed?--
LEFT JOIN  fixturef_testing.users u 
  on u.id = f.refereeid
LEFT JOIN  fixturef_testing.competition c 
  on c.id = f.competitionid
--Not sure what the above joins are for...
--Get the table Teams record for the home team
LEFT JOIN Teams HT  
 on HT.ID = f.hometeamID 
--Get the table Teams record for the away team
LEFT JOIN Teams AT
 on AT.ID = f.awayTeamID
WHERE f.active = 1

在行

1 个答案: