Mongoose 方法 findOne 耗时太长，有时返回 undefined

Question

Im calling findOne to find a user and then Im saving his commands into my variable commands, which I return and it is sometimes undefined.

const findAllCommands = async (user) => {
const commands = [];
const cache = await checkCache(user);
if (cache) {
  logger.info('Existing CACHE found!');
  return cache;
}
await User.findOne({ username: user }, (err, res) => {
if (err) {
  logger.error('ERROR: ' + err);
  throw new Error(err);
}
res.commands.forEach((v) => {
  commands.push(v);})
});

await addToCache(user, JSON.stringify(commands));
return commands;
};

Answer 1

I use a try catch block whenever I use async await syntax. Also if you need only one field you can query only for that field.

const findAllCommands = async (user) => {
  try {
    const cache = await checkCache(user);
    if (cache) {
      logger.info('Existing CACHE found!');
      return cache;
    }
    const commands = await User.findOne({ username: user }, "commands");
    await addToCache(user, JSON.stringify(commands));
    return commands;
  } catch(error) {
    console.log(error)
  }
};