我的google和stockoverflow搜索失败了，所以我需要你的帮助。我有一张table

+------+------+------+------------+
| id   | Loc  | MEL  | COUNT(MEL) |
+------+------+------+------------+
|    1 | AAA  | A    |          1 |
|    2 | BBB  | B    |          1 |
|    3 | CCC  | C    |          1 |
|    4 | AAA  | D    |          1 |
|    5 | AAA  | A    |          1 |
|    6 | BBB  | B    |          1 |
|    7 | BBB  | C    |          1 |
|    8 | AAA  | D    |          1 |
+------+------+------+------------+

我想将其转换为下表：

+------+------+------+------+
| MEL  | AAA  | BBB  | CCC  |
+------+------+------+------+
| A    |  2   |      |      |
| B    |      |   2  |      |
| C    |      |   1  |   1  |
| D    |  2   |      |   1  |
+------+------+------+------+

计数和大小写的所有组合何时不起作用？
获取下表的代码：

CREATE TABLE Orders
(
id INT,
Loc char(255),
MEL char (10))

insert into Orders values 
(1,   "AAA", "A"),
(2,   "BBB", "B"),
(3,   "CCC", "C"),
(4,   "AAA", "D"),
(5,   "AAA", "A"),
(6,   "BBB", "B"),
(7,   "BBB", "C"),
(8,   "AAA", "D");