mysql - 在 MYSQL 中重新映射行

Question

我有这样的表：

uid | 确定 | 价值
1 | 1 | nameOf1
1 | 2 | 姓氏Of1
1 | 3 | 国家/地区
2 | 1 | nameOf2
2 | 2 | 姓Of2

并且需要像这样转换/选择它：

uid | 姓名 | 姓氏 | 国家
1 | nameOf1 | 姓氏Of1 | 国家/地区
2 | nameOf2 | 姓Of2 | ..

Answer 1

尝试类似：

SELECT t1.uid, t2.value AS name, t3.value AS surname, t4.value AS country FROM table t1
  LEFT JOIN table t2 on t2.uid = t1.uid AND t2.fid = 1
  LEFT JOIN table t3 on t3.uid = t1.uid AND t3.fid = 2
  LEFT JOIN table t4 on t4.uid = t1.uid AND t4.fid = 3
  GROUP BY t1.uid;

或者：

SELECT DISTINCT t1.uid, t2.value AS name, t3.value AS surname, t4.value AS country FROM table t1
  LEFT JOIN table t2 on t2.uid = t1.uid AND t2.fid = 1
  LEFT JOIN table t3 on t3.uid = t1.uid AND t3.fid = 2
  LEFT JOIN table t4 on t4.uid = t1.uid AND t4.fid = 3;

Answer 2

It's a little complex, but you could do something like:

select distinct uid as uid,
   (select value from dataTable as table1 
           where table1.uid=dataTable.uid and fid = 1) as name,
   (select value from dataTable as table2 
           where table2.uid=dataTable.uid and fid = 2) as surname,
   (select value from dataTable as table3 
           where table3.uid=dataTable.uid and fid = 3) as country
from dataTable group by uid

SQLFiddle