java中对数据库进行增删改查的代码
时间: 2024-02-27 15:57:58 浏览: 25
以下是使用Java进行数据库增删改查的示例代码:
1. 建立数据库连接
```java
String url = "jdbc:mysql://localhost:3306/dbname";
String username = "root";
String password = "password";
Connection connection = DriverManager.getConnection(url, username, password);
```
2. 数据库查询
```java
String sql = "SELECT * FROM tablename WHERE column = ?";
PreparedStatement statement = connection.prepareStatement(sql);
statement.setString(1, "value");
ResultSet result = statement.executeQuery();
while (result.next()) {
// 处理查询结果
}
result.close();
statement.close();
```
3. 数据库插入
```java
String sql = "INSERT INTO tablename (column1, column2) VALUES (?, ?)";
PreparedStatement statement = connection.prepareStatement(sql);
statement.setString(1, "value1");
statement.setString(2, "value2");
statement.executeUpdate();
statement.close();
```
4. 数据库更新
```java
String sql = "UPDATE tablename SET column1 = ? WHERE column2 = ?";
PreparedStatement statement = connection.prepareStatement(sql);
statement.setString(1, "new value");
statement.setString(2, "condition");
statement.executeUpdate();
statement.close();
```
5. 数据库删除
```java
String sql = "DELETE FROM tablename WHERE column = ?";
PreparedStatement statement = connection.prepareStatement(sql);
statement.setString(1, "value");
statement.executeUpdate();
statement.close();
```
注:以上示例代码仅供参考,实际应用中需要根据具体情况进行调整和优化。