SQL DELETE 语句

SQL DELETE 语句用于从表中删除现有记录。

可以在 DELETE 语句中使用 WHERE 子句来删除选定的行，否则所有记录都将被删除。

语法

带有 WHERE 子句的 DELETE 语句的基本语法如下

DELETE FROM table_name
WHERE [condition];

我们可以使用 AND 或 OR 运算符组合 N 个条件。

示例

使用 CUSTOMERS 表

+----+----------+-----+-----------+----------+
| ID | NAME     | AGE | ADDRESS   | SALARY   |
+----+----------+-----+-----------+----------+
|  1 | Ramesh   |  32 | Ahmedabad |  2000.00 |
|  2 | Khilan   |  25 | Delhi     |  1500.00 |
|  3 | kaushik  |  23 | Kota      |  2000.00 |
|  4 | Chaitali |  25 | Mumbai    |  6500.00 |
|  5 | Hardik   |  27 | Bhopal    |  8500.00 |
|  6 | Komal    |  22 | MP        |  4500.00 |
|  7 | Muffy    |  24 | Indore    | 10000.00 |
+----+----------+-----+-----------+----------+

下面的代码删除一个ID为6的客户。

SQL> DELETE FROM CUSTOMERS
WHERE ID = 6;

CUSTOMERS 表将具有以下记录。

+----+----------+-----+-----------+----------+
| ID | NAME     | AGE | ADDRESS   | SALARY   |
+----+----------+-----+-----------+----------+
|  1 | Ramesh   |  32 | Ahmedabad |  2000.00 |
|  2 | Khilan   |  25 | Delhi     |  1500.00 |
|  3 | kaushik  |  23 | Kota      |  2000.00 |
|  4 | Chaitali |  25 | Mumbai    |  6500.00 |
|  5 | Hardik   |  27 | Bhopal    |  8500.00 |
|  7 | Muffy    |  24 | Indore    | 10000.00 |
+----+----------+-----+-----------+----------+

如果你想从 CUSTOMERS 表中删除所有记录，则不需要使用 WHERE 子句，DELETE 语句如下

SQL> DELETE FROM CUSTOMERS;

现在，CUSTOMERS 表没有任何记录。