java连接mysql数据库实现增删改查功能

以下是Java连接MySQL数据库实现增删改查功能的示例代码：

1. 连接数据库：

import java.sql.Connection;
import java.sql.DriverManager;
import java.sql.SQLException;

public class Connect {
    private static final String URL = "jdbc:mysql://localhost:3306/database_name";
    private static final String USERNAME = "username";
    private static final String PASSWORD = "password";

    public Connection getConnection() throws SQLException {
        return DriverManager.getConnection(URL, USERNAME, PASSWORD);
    }
}

2. 添加数据：

public void tianjia(String id, String name, String score) {
    try {
        Connect ct = new Connect();
        Connection conn = ct.getConnection();
        String sql = "INSERT INTO student(id, name, score) VALUES(" + id + ", '" + name + "', " + score + ")";
        conn.createStatement().executeUpdate(sql);
        conn.close();
    } catch (Exception e) {
        System.err.println(e.getMessage());
    }
}

3. 修改数据：

public void xiugai(String id, String name, String score) {
    try {
        Connect ct = new Connect();
        Connection conn = ct.getConnection();
        String sql = "UPDATE student SET name = '" + name + "', score = " + score + " WHERE id = " + id;
        conn.createStatement().executeUpdate(sql);
        conn.close();
    } catch (Exception e) {
        System.err.println(e.getMessage());
    }
}

4. 查询数据：

public void chaxun() {
    try {
        Connect ct = new Connect();
        Connection conn = ct.getConnection();
        String sql = "SELECT * FROM student";
        ResultSet rs = conn.createStatement().executeQuery(sql);
        while (rs.next()) {
            String id = rs.getString("id");
            String name = rs.getString("name");
            String score = rs.getString("score");
            System.out.println("ID: " + id + ", Name: " + name + ", Score: " + score);
        }
        conn.close();
    } catch (Exception e) {
        System.err.println(e.getMessage());
    }
}