java mysql数据库判断是否存在

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

public class DatabaseExistenceCheck {

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

        try (Connection conn = DriverManager.getConnection(url, username, password)) {
            String sql = "SELECT 1 FROM users WHERE username = ?";
            try (PreparedStatement ps = conn.prepareStatement(sql)) {
                ps.setString(1, targetUsername);
                try (ResultSet rs = ps.executeQuery()) {
                    if (rs.next()) {
                        System.out.println("用户存在");
                    } else {
                        System.out.println("用户不存在");
                    }
                }
            }
        } catch (SQLException e) {
            e.printStackTrace();
        }
    }
}