package study.u45;

import java.sql.Connection;
import java.sql.DriverManager;
import java.sql.ResultSet;
import java.sql.Statement;

/** 应急清理：仅删除程序参数指名的 study_u45_* schema，删除成功以进程退出码 0 表达。 */
public class U45Cleanup {

    public static void main(String[] args) throws Exception {
        if (args.length != 1 || !args[0].startsWith("study_u45_")) {
            System.err.println("用法: U45Cleanup study_u45_<id>");
            System.exit(2);
        }
        try (Connection connection = DriverManager.getConnection("jdbc:mysql://127.0.0.1:3306/", "root", "");
             Statement statement = connection.createStatement()) {
            statement.execute("DROP DATABASE IF EXISTS " + args[0]);
            try (ResultSet rs = statement.executeQuery("SHOW DATABASES LIKE '" + args[0] + "'")) {
                if (rs.next()) {
                    System.err.println("schema 仍存在: " + args[0]);
                    System.exit(1);
                }
            }
        }
        System.out.println("U45 emergency-cleanup=PASS own-schema=removed");
    }
}