字段列表

Question

我正在学习MYSQL并且我得到了错误

  

字段列表中的未知列event_id

但是我在两个表中都有这个列

SELECT 
event_id.events,
tournament.events, 
team1.events,
team2.events,event_date.events,
venue.events, picks.pick,tournament.picks
FROM  events 
INNER JOIN picks 
ON  `event_id`.events = `event_id`.picks
 WHERE tournament = 'SUPER15'

我已经检查过并进行了调整并尝试过，但我无法弄清楚出了什么问题......

表事件

表格选择

Answer 1

首先应该是表名或别名，而不是列名，如下所示

 SELECT
    events.event_id,
    events.tournament, 
    events.team1, 
    events.team2,
    events.event_date,
    events.venue, 
    picks.pick,
    picks.tournament
FROM  events 
    INNER JOIN picks ON  
           events.`event_id` = picks.`event_id`
    WHERE 
        events.tournament = 'SUPER15'

您还必须为条件WHERE tournament = 'SUPER15'添加列名。我将其更改为WHERE events.tournament = 'SUPER15'。我还建议你使用如下的别名

  SELECT 
       E.event_id,
       E.tournament, 
       E.team1, 
       E.team2,
       E.event_date,
       E.venue, 
       P.pick,
       P.tournament
 FROM  events E
    INNER JOIN picks P ON  
              E.`event_id` = P.`event_id`
    WHERE 
        E.tournament = 'SUPER15'

它更具可读性，不是吗？

Answer 2

您以相反的顺序指定您的选择。它应该是onPostExecute：

table.column