我该如何转变
SELECT
FieldA
FieldB
FieldC
FROM mydata
ORDER BY FieldA;
+------------------------------------------+-------------------+-----------------+
| FieldA | FieldB | FieldC |
+------------------------------------------+-------------------+-----------------+
| 123 | cca | 23 |
| 123 | dde | 12 |
| 234 | cca | 44 |
| 234 | dde | 32 |
| 456 | dde | 11 |
| 456 | cca | 45 |
+------------------------------------------+-------------------+-----------------+
对此：
+------------------------------------------+-------------------+-----------------+
| FieldA | cca | dde |
+------------------------------------------+-------------------+-----------------+
| 123 | 23 | 12 |
| 234 | 44 | 32 |
| 456 | 32 | 11 |
+------------------------------------------+-------------------+-----------------+
最佳答案
尝试这样的事情：
SELECT
FieldA AS FieldA,
SUM(IF(FieldB='cca', FieldC, 0)) AS cca,
SUM(IF(FieldB='dde', FieldC, 0)) AS dde
FROM mydata
GROUP BY FieldA
ORDER BY FieldA;
关于mysql - mysql-转换返回的数据，将字段值设置为新列，我们在Stack Overflow上找到一个类似的问题：https://stackoverflow.com/questions/6552412/