mysql - 将行与列 mysql 连接

Question

我有两个表，我需要从中选择数据

用户

id   email
----------
1   email1
2   email2

设置

usrid name    value
--------------------
1    set1     value1
1    set2     value2
2    set1     value1
2    set2     value2

我使用的sql是

SELECT u.email, s . * 
FROM `sers` u
INNER JOIN `settings` s ON u.id = s.usrid
LIMIT 0 , 30

但我明白了

email  name value
------------------
email1  set1  value1
email1  set1  value1
email2  set2  value2
email2  set2  value1

有什么办法可以得到

email1  set1 value1 set1 value1 etc
email2  set2 value2 set2 value2 etc

从 group_concat 我试过这个

SELECT u.email, GROUP_CONCAT(s.name,s.value) as vals FROM `users` u INNER JOIN `settings` s ON u.id = s.usrid GROUP BY u.email

这给了

email1  set1value1,set1value1 etc

我怎样才能在逗号之间的每个值之间放置一个分隔符

喜欢

email1  set1=value1,set1=value1 etc

Answer 1

使用GROUP_CONCAT()和GROUP BY。

Answer 2

SELECT u.email,
GROUP_CONCAT(s.name,'='  ,s.value SEPARATOR ',')
FROM `user` u
INNER JOIN `settings` s ON u.id = s.usrid
GROUP BY u.email;

Answer 3

试试这个小提琴：

http://sqlfiddle.com/#!2/782e3/6

SELECT u.email, CONCAT_WS(',', GROUP_CONCAT( s.name),
                 GROUP_CONCAT( s.value)) AS allValues
FROM `user` u
INNER JOIN `settings` s ON u.id = s.usrid GROUP BY email
LIMIT 0 , 30