摘要:重複資料查詢
這篇有兩個狀況
- 列出重複的項目，一種列一筆
- 列出重複的項目，有幾項列幾項
| ID | Content |
| 1 | AAA |
| 2 | AAA |
| 3 | BBB |
| 4 | CCC |
| 5 | CCC |
在1的情況下會出現
| ID | Content |
| 1 | AAA |
| 4 | CCC |
語法:
SELECT * FROM Table Group by Content Having Count(*) > 1
在2的情況下會出現
| ID | Content |
| 1 | AAA |
| 2 | AAA |
| 4 | CCC |
| 5 | CCC |
語法:
SELECT *
FROM Table
WHERE Content IN (SELECT Content FROM Table Group by Contnet HAVING COUNT(*) > 1)
