const mysql = require('mysql2/promise');
(async () => {
  const c = await mysql.createConnection({
    host: 'localhost', user: 'root', password: '74191221', database: 'competition_db'
  });
  try {
    await c.query("ALTER TABLE exam_submissions ADD COLUMN word_file_path VARCHAR(500) NULL DEFAULT NULL COMMENT 'Word答案文件路径' AFTER answers");
    console.log('Added word_file_path');
  } catch (e) {
    if (e.code === 'ER_DUP_FIELDNAME') console.log('word_file_path exists');
    else throw e;
  }
  try {
    await c.query("ALTER TABLE exam_submissions ADD COLUMN word_file_name VARCHAR(255) NULL DEFAULT NULL COMMENT 'Word答案文件名' AFTER word_file_path");
    console.log('Added word_file_name');
  } catch (e) {
    if (e.code === 'ER_DUP_FIELDNAME') console.log('word_file_name exists');
    else throw e;
  }
  const [cols] = await c.query('SHOW COLUMNS FROM exam_submissions');
  cols.forEach(x => console.log(x.Field, x.Type, x.Null));
  await c.end();
})();