mysql 拼接的sql语句

String sql = "SELECT * FROM users WHERE username = ? AND password = ?";
try (PreparedStatement pstmt = connection.prepareStatement(sql)) {
    pstmt.setString(1, username);
    pstmt.setString(2, password);
    ResultSet rs = pstmt.executeQuery();
    // 处理结果集
} catch (SQLException e) {
    e.printStackTrace();
}

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

public class MySQLExample {
    public static void main(String[] args) {
        String url = "jdbc:mysql://localhost:3306/mydatabase";
        String username = "myuser";
        String password = "mypassword";

        String sql = "SELECT * FROM users WHERE username = ? AND password = ?";
        try (Connection connection = DriverManager.getConnection(url, username, password);
             PreparedStatement pstmt = connection.prepareStatement(sql)) {
            pstmt.setString(1, "admin");
            pstmt.setString(2, "password123");
            ResultSet rs = pstmt.executeQuery();
            while (rs.next()) {
                System.out.println("User ID: " + rs.getInt("id"));
                System.out.println("Username: " + rs.getString("username"));
            }
        } catch (SQLException e) {
            e.printStackTrace();
        }
    }
}