MySQL DELETE 语句
MySQL DELETE 语句
MySQL DELETE 语句用于删除表中的现有记录。
DELETE 语法
DELETE FROM table_name WHERE condition;注意: 删除表中的记录时要小心！请注意 DELETE 语句中的 WHERE 子句。 WHERE 子句指定要删除的记录。如果省略 WHERE 子句，则将删除表中的所有记录！
演示数据库
以下是 Northwind 示例数据库中 "Customers" 表中的部分数据
| CustomerID | CustomerName | ContactName | Address | City | PostalCode | Country |
|---|---|---|---|---|---|---|
| 1 |
Alfreds Futterkiste | Maria Anders | Obere Str. 57 | Berlin | 12209 | Germany |
| 2 | Ana Trujillo Emparedados y helados | Ana Trujillo | Avda. de la Constitución 2222 | México D.F. | 05021 | Mexico |
| 3 | Antonio Moreno Taquería | Antonio Moreno | Mataderos 2312 | México D.F. | 05023 | Mexico |
| 4 |
Around the Horn | Thomas Hardy | 120 Hanover Sq. | London | WA1 1DP | UK |
| 5 | Berglunds snabbköp | Christina Berglund | Berguvsvägen 8 | Luleå | S-958 22 | Sweden |
SQL DELETE 例子
以下 SQL 语句会从 "Customers" 表中删除客户 "Alfreds Futterkiste"
示例
DELETE FROM Customers WHERE CustomerName='Alfreds Futterkiste';
"Customers" 表现在将看起来像这样
| CustomerID | CustomerName | ContactName | Address | City | PostalCode | Country |
|---|---|---|---|---|---|---|
| 2 | Ana Trujillo Emparedados y helados | Ana Trujillo | Avda. de la Constitución 2222 | México D.F. | 05021 | Mexico |
| 3 | Antonio Moreno Taquería | Antonio Moreno | Mataderos 2312 | México D.F. | 05023 | Mexico |
| 4 |
Around the Horn | Thomas Hardy | 120 Hanover Sq. | London | WA1 1DP | UK |
| 5 | Berglunds snabbköp | Christina Berglund | Berguvsvägen 8 | Luleå | S-958 22 | Sweden |
删除所有记录
可以在不删除表的情况下删除表中的所有行。这意味着表结构、属性和索引将保持完整
DELETE FROM table_name;以下 SQL 语句将删除 "Customers" 表中的所有行，但不删除表本身
示例
DELETE FROM Customers;
