使用PreparedStatement在where子句中传递字符串

import java.sql.*;

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

        try (Connection conn = DriverManager.getConnection(url, user, password)) {
            String sql = "SELECT * FROM users WHERE username = ?";
            try (PreparedStatement pstmt = conn.prepareStatement(sql)) {
                // 设置参数
                pstmt.setString(1, "john_doe");

                // 执行查询
                try (ResultSet rs = pstmt.executeQuery()) {
                    while (rs.next()) {
                        System.out.println("User ID: " + rs.getInt("id"));
                        System.out.println("Username: " + rs.getString("username"));
                        System.out.println("Email: " + rs.getString("email"));
                    }
                }
            }
        } catch (SQLException e) {
            e.printStackTrace();
        }
    }
}