表字段值与另一表字段名相同问题。
现有表A:
A1 A2 A3
1 2 工资
2 3 分红
3 1 奖金
表B:
工资 奖金 加班工资 分红 ….（还有很多其他字段）
1 3 1 2
2 2 3 2
3 1 3 3
怎样根据表A的A3字段值将表B里对应字段名（表A的A3字段值为表B的全部字段名的一部分）的内容取出来？求高手指点一二！感激不尽！！
猜 lz 要的是这个？
-
SQL code
mysql> select * from config;
+----+----------+
| id | name |
+----+----------+
| 1 | salary |
| 2 | bonus |
| 3 | overtime |
+----+----------+
3 rows in set (0.00 sec)
mysql> select * from data;
+--------+-------+----------+
| salary | bonus | overtime |
+--------+-------+----------+
| 1 | 2 | 4 |
| 3 | 3 | 3 |
+--------+-------+----------+
2 rows in set (0.00 sec)
mysql> select @sql := concat("select ", group_concat(name), " from data;")
-> from config
-> where id in (1, 2);
+--------------------------+
| @sql := concat("select ", group_concat(name), " from data;") |
+--------------------------+
| select salary,bonus from data; |
+--------------------------+
1 row in set (0.00 sec)
mysql>
mysql> prepare sp from @sql;
Query OK, 0 rows affected (0.00 sec)
Statement prepared
mysql> execute sp;
+--------+-------+
| salary | bonus |
+--------+-------+
| 1 | 2 |
| 3 | 3 |
+--------+-------+
2 rows in set (0.00 sec)
mysql> drop prepare sp;
Query OK, 0 rows affected (0.00 sec)
http://blog.csdn.net/acmain_chm/article/details/4283943
MySQL交叉表
在某些数据库中有交叉表，但在MySQL中却没有这个功能，但网上看到有不少朋友想找出一个解决方法，特发贴集思广义。http://topic.csdn.net/u/20090530/23/0b782674-4b0b-4cf5-bc1a-e8914aaee5ab.html?96198现整理解法如下：数据样本： create table tx( id int primary key, c1 c...
