Delete 刪除紀錄

1. 先列出資料表中的紀錄。

   MariaDB root@(none):dyw> select * from tbl;
   +----+---------+--------+-----------------+
   | id | title   | author | submission_date |
   +----+---------+--------+-----------------+
   | 1  | C++     | peter  | 2025-11-10      |
   | 2  | Linux   | linux  | 2025-11-10      |
   | 3  | Mariadb | dywang | 2025-11-11      |
   +----+---------+--------+-----------------+
   
   3 rows in set
   Time: 0.012s
   

2. 如果 DELETE 命令不配合 WHERE 條件使用，會刪除資料表中的所有資料。只刪除 id=2 的紀錄。

   MariaDB root@(none):dyw> delete from tbl where id=3;
   You're about to run a destructive command.
   Do you want to proceed? (y/n): y
   Your call!
   Query OK, 1 row affected
   Time: 0.022s
   

3. 再查詢資料表 tbl，只剩下兩筆紀錄。

   MariaDB root@(none):dyw> select * from tbl;
   +----+-------+--------+-----------------+
   | id | title | author | submission_date |
   +----+-------+--------+-----------------+
   | 1  | C++   | peter  | 2025-11-10      |
   | 2  | Linux | linux  | 2025-11-10      |
   +----+-------+--------+-----------------+
   
   2 rows in set
   Time: 0.016s