SQL delete 语句,删除表数据
SQL DELETE 语句
DELETE 语句用于删除表中的行。
SQL DELETE 语法
DELETE FROM table_name WHERE some_column=some_value;
请注意 SQL DELETE 语句中的 WHERE 子句! WHERE 子句规定哪条记录或者哪些记录需要删除。如果您省略了 WHERE 子句,所有的记录都将被删除!
实例
实例表
+----+--------------+---------------------------+-------+---------+
| id | name | url | alexa | country |
+----+--------------+---------------------------+-------+---------+
| 1 | Google | https://www.google.cm/ | 1 | USA |
| 2 | 淘宝 | https://www.taobao.com/ | 13 | CN |
| 3 | Facebook | https://www.facebook.com/ | 3 | USA |
| 4 | 百度 | https://www.baidu.com/ | 4 | CN |
+----+--------------+---------------------------+-------+---------+
删除facebook
DELETE FROM Websites
WHERE name='Facebook' AND country='USA';
结果:
+----+--------------+---------------------------+-------+---------+
| id | name | url | alexa | country |
+----+--------------+---------------------------+-------+---------+
| 1 | Google | https://www.google.cm/ | 1 | USA |
| 2 | 淘宝 | https://www.taobao.com/ | 13 | CN |
| 4 | 百度 | https://www.baidu.com/ | 4 | CN |
+----+--------------+---------------------------+-------+---------+
删除所有数据
您可以在不删除表的情况下,删除表中所有的行。这意味着表结构、属性、索引将保持不变:
DELETE FROM table_name;
注释:在删除记录时要格外小心!因为您不能重来!