查询多表

Question

我有四个表：

• 字符
• arena_team
• arena_table_member
• arena_team_stats。

字符表有GUID，名称

arena_team表有arenateamid，name，type

arena_table_member表有guid（这与字符表中的相同），arenateamid

arena_team_stats表有arenateamid，评级，wins，wins2，播放

如何获取角色的竞技场团队列表？我尝试了：

$result=mysql_query("SELECT 
          characters.guid
           , characters.name
           , arena_team.arenateamid
           , arena_team.name
           , arena_team_stats.rating
           , arena_team_stats.wins
           , arena_team_stats.wins2
           , arena_team_stats.played
           , arena_team.type 
   FROM characters
           , arena_team_stats
           , arena_team 
    WHERE characters.name LIKE '%$q%' 
    AND arena_team.arenateamid = arena_team_stats.arenateamid 
    ORDER BY arena_team_stats.rating DESC") 
or die(mysql_error());

.

但它返回了arena_team表中的所有竞技场团队。

Answer 1

看起来你错过了一个加入。使用表别名和格式化更容易阅读：

    SELECT c.guid
         , c.name
         , at.arenateamid
         , at.name
         , at.type
         , ats.rating
         , ats.wins
         , ats.wins2 
         , ats.played
      FROM characters c
INNER JOIN arena_team_member atm ON atm.guid = c.guid
INNER JOIN arena_team at ON at.arenateamid = atm.arenateamid
INNER JOIN arena_team_stats ats ON ats.arenateamid = at.arenateamid
     WHERE c.name LIKE '%$q%'
  ORDER BY ats.rating DESC

.

Answer 2

你应该使用连接。在从部分中使用逗号分隔表时，您可以获得结果。

尝试此查询（使用加入）：

SELECT c.guid,c.name,a.arenateamid,a.name,
  ts.rating,ts.wins,ts.wins2,
  ts.played,a.type 
 FROM characters c
         JOIN arena_table_member ON arena_table_member.guid=character.guid
  JOIN arena_team a ON arena_table_member.arenateamid = a.arenateamid
  JOIN arena_team_stats ts ON ts.arenateamid = a.arenateamid
 WHERE c.name LIKE '%$q%' 
  AND a.arenateamid = ts.arenateamid 
 ORDER BY ts.rating DESC

.

两件事：

1. 您应该在此处使用别名。（上面的c，a，ts而不是完整表名称称为aliases）

2. 如果您想完全匹配字符'？'，请使用c.name=''。c.name喜欢'％？％'将返回所有的c.names？在他们之中。

Answer 3

SELECT Char.guid, Chars.name, Teams.arenateamid, Teams.name, Stats.rating,
       Stats.wins, Stats.wins2, Stats.played, Teams.type
FROM characters AS Chars,arena_team_stats AS Stats, arena_team AS Teams,
     arena_table_member AS Members
WHERE Chars.name LIKE '%$q%' AND Teams.arenateamid = Stats.arenateamid AND
      Members.guid = Chars.guid AND Members.arenateamid = Teams.arenateamid
ORDER BY Stats.rating DESC

.

你缺少一些桌子加入。