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我正在計算下表中每個id的匹配行數。雖然有一種選擇是創建另一個表來跟蹤每個類別的計數,但我寧願在不創建第二個表(最好沒有臨時表)的情況下解決此問題。選擇MySQL中特定列的匹配行數
我的表:
+---------+----------------+
| id | category |
+---------+----------------+
| 3611383 | AAAAAAAAAAAAAA |
| 3611382 | AAAAAAAAAAAAAA |
| 3611381 | AAAAAAAAAAAAAA |
| 3611378 | AAAAAAAAAAAAAA |
| 3611377 | AAAAAAAAAAAAAA |
| 3611376 | AAAAAAAAAAAAAA |
| 3611374 | AAAAAAAAAAAAAA |
| 3611373 | AAAAAAAAAAAAAA |
| 3611372 | BBBBBBBBBBBBBB |
| 3611371 | BBBBBBBBBBBBBB |
| 3611370 | BBBBBBBBBBBBBB |
| 3611369 | BBBBBBBBBBBBBB |
| 3611366 | CCCCCCCCCCCCCC |
| 3611365 | CCCCCCCCCCCCCC |
| 3611364 | CCCCCCCCCCCCCC |
+---------+----------------+
所需的輸出:
+---------+----------------+---------+
| id | category | count |
+---------+----------------+---------+
| 3611383 | AAAAAAAAAAAAAA | 8 |
| 3611382 | AAAAAAAAAAAAAA | 8 |
| 3611381 | AAAAAAAAAAAAAA | 8 |
| 3611378 | AAAAAAAAAAAAAA | 8 |
| 3611377 | AAAAAAAAAAAAAA | 8 |
| 3611376 | AAAAAAAAAAAAAA | 8 |
| 3611374 | AAAAAAAAAAAAAA | 8 |
| 3611373 | AAAAAAAAAAAAAA | 8 |
| 3611372 | BBBBBBBBBBBBBB | 4 |
| 3611371 | BBBBBBBBBBBBBB | 4 |
| 3611370 | BBBBBBBBBBBBBB | 4 |
| 3611369 | BBBBBBBBBBBBBB | 4 |
| 3611366 | CCCCCCCCCCCCCC | 3 |
| 3611365 | CCCCCCCCCCCCCC | 3 |
| 3611364 | CCCCCCCCCCCCCC | 3 |
+---------+----------------+---------+
我已經得到的最接近的是
SELECT id, category, count(category) AS c FROM mytable ORDER BY id DESC;
,但將產品只有一行:
+---------+----------------+---------+
| id | category | c |
+---------+----------------+---------+
| 3611383 | AAAAAAAAAAAAAA | 8 |
+---------+----------------+---------+
謝謝,那就是我一直在尋找的! –