如何删除重复的SQL结果？

Question

我从名为 guildmembers

的表中提取访问权限，guildid名称

...来自另一个名为玩家

的表格中的id，level，playerclass

这是我的SQL语句：

SELECT guildmembers.access, guildmembers.guildid, guildmembers.name, players.id, players.level, players.playerclass
FROM guildmembers, players
ORDER BY guildmembers.name, players.playerclass

这就是回报。

这就是我需要的。

任何想法如何做到这一点？

Answer 1

您需要做的是加入声明。目前你告诉sql只显示两个表中的所有resutls。您希望仅在匹配时显示结果，为此您使用连接语句。

SELECT guildmembers.access, guildmembers.guildid, guildmembers.name, players.id, players.level, players.playerclass
FROM guildmembers join players on guildmembers.pid=players.id
ORDER BY guildmembers.name, players.playerclass

guildmembers.pid和players.id是两个表中的公共字段，因此您可以加入这些表格。

http://www.w3schools.com/sql/sql_join.asp

使这更容易理解和理解在两个表中都有一个共同的字段名称。然后你可以使用它来加入它，这更有意义。

希望能帮到你。

Answer 2

您的SQL语句不正确，请尝试

SELECT guildmembers.access, guildmembers.guildid, guildmembers.name, players.id, 
players.level, players.playerclass from guildmembers left join players on guildmembers.pid = players.id order by guildmembers.name, players.playerclass

Answer 3

SELECT gm.access as access, gm.guildid as guildid, gm.name as name, 
p.id as id, p.level as level, p.playerclass as playerclass
FROM guildmembers gm LEFT JOIN players p on gm.pid=p.id
ORDER BY gm.name, p.playerclass