使用JDBC连接数据库
时间: 2024-01-18 09:40:26 浏览: 23
好的,以下是使用JDBC连接数据库的基本步骤:
1. 导入JDBC驱动包,例如MySQL的驱动包:`mysql-connector-java.jar`。
2. 加载JDBC驱动程序:`Class.forName("com.mysql.jdbc.Driver");`
3. 建立数据库连接:`Connection conn = DriverManager.getConnection(url, user, password);`
其中,url为连接数据库的URL,例如`jdbc:mysql://localhost:3306/test`;user和password为数据库的用户名和密码。
4. 创建一个Statement对象,用于执行SQL语句:`Statement stmt = conn.createStatement();`
5. 执行SQL语句并处理结果:
```
String sql = "SELECT * FROM users";
ResultSet rs = stmt.executeQuery(sql);
while(rs.next()) {
int id = rs.getInt("id");
String name = rs.getString("name");
int age = rs.getInt("age");
System.out.println("id: " + id + ", name: " + name + ", age: " + age);
}
```
6. 关闭连接和Statement对象:`rs.close(); stmt.close(); conn.close();`
完整示例代码如下:
```java
import java.sql.*;
public class JdbcDemo {
public static void main(String[] args) {
String url = "jdbc:mysql://localhost:3306/test";
String user = "root";
String password = "123456";
try {
Class.forName("com.mysql.jdbc.Driver");
Connection conn = DriverManager.getConnection(url, user, password);
Statement stmt = conn.createStatement();
String sql = "SELECT * FROM users";
ResultSet rs = stmt.executeQuery(sql);
while(rs.next()) {
int id = rs.getInt("id");
String name = rs.getString("name");
int age = rs.getInt("age");
System.out.println("id: " + id + ", name: " + name + ", age: " + age);
}
rs.close();
stmt.close();
conn.close();
} catch (ClassNotFoundException e) {
e.printStackTrace();
} catch (SQLException e) {
e.printStackTrace();
}
}
}
```