jdbc增删改查代码
时间: 2023-11-21 14:50:09 浏览: 81
以下是Java中使用JDBC进行增删改查操作的示例代码:
1. 导入必要的包:
```java
import java.sql.Connection;
import java.sql.DriverManager;
import java.sql.PreparedStatement;
import java.sql.ResultSet;
import java.sql.SQLException;
```
2. 建立数据库连接:
```java
String url = "jdbc:mysql://localhost:3306/mydb";
String user = "username";
String password = "password";
Connection conn = DriverManager.getConnection(url, user, password);
```
3. 插入数据:
```java
String insertQuery = "INSERT INTO mytable (column1, column2) VALUES (?, ?)";
PreparedStatement insertStmt = conn.prepareStatement(insertQuery);
insertStmt.setString(1, value1);
insertStmt.setString(2, value2);
insertStmt.executeUpdate();
```
4. 更新数据:
```java
String updateQuery = "UPDATE mytable SET column1 = ? WHERE column2 = ?";
PreparedStatement updateStmt = conn.prepareStatement(updateQuery);
updateStmt.setString(1, newValue);
updateStmt.setString(2, conditionValue);
updateStmt.executeUpdate();
```
5. 删除数据:
```java
String deleteQuery = "DELETE FROM mytable WHERE column1 = ?";
PreparedStatement deleteStmt = conn.prepareStatement(deleteQuery);
deleteStmt.setString(1, conditionValue);
deleteStmt.executeUpdate();
```
6. 查询数据:
```java
String selectQuery = "SELECT * FROM mytable WHERE column1 = ?";
PreparedStatement selectStmt = conn.prepareStatement(selectQuery);
selectStmt.setString(1, conditionValue);
ResultSet resultSet = selectStmt.executeQuery();
while(resultSet.next()) {
String value1 = resultSet.getString("column1");
String value2 = resultSet.getString("column2");
// 处理查询结果
}
```
7. 关闭连接:
```java
resultSet.close();
selectStmt.close();
conn.close();
```
请确保替换代码中的数据库连接信息、SQL查询语句和参数值,并根据实际情况进行修改。