Question

我有一个功能，基本上是verify if one can update the entry in the database > update the entry

的简单格式

使用ORM航行时（吃水线）。

当前端在api端点一次发送多个请求（或一次到达多个请求）时，会发生问题。那时，对这些条目的验证失败，更新条目意味着其他验证也会更改。

我尝试通过使用事务来解决此问题：据我所知，事务意味着数据存储更新阻止在另一个事务仍很忙时进行更新吗？

代码：

const new_entry = await sails.getDatastore().transaction(async (db) => {
  console.log(`${entry_id}: transaction started`);
  if (section_name) {
    const event_id: number = typeof entry.event === 'number' ? entry.event : entry.event.id;
    section = await Section.findOne({
      where: {
        name: section_name,
        event: event_id,
      }
    }).usingConnection(db);
    if (!section) {
      throw new BadParamsError('section not found');
    }
    console.log(`${entry_id}: before full check`);
    const existing = await Entry.find({
      event: event_id,
      section: section.id,
    }).usingConnection(db);
    console.log(`${entry_id}: before updating items: ${existing.length}`);
    //if existing is larger than free spots do something....
    section_id = section.id;
    console.log(`${entry_id}: start update`);
    const new_entry = await Entry.update({id: entry_id}).set({
      section: section_id
    }).usingConnection(db).fetch();
    const existing_after = await Entry.find({
      event: event_id,
      section: section.id,
    }).usingConnection(db);
    console.log(`${entry_id}: after updating items: ${existing_after.length}`);
    console.log(`${entry_id}: transaction ended`);
    return new_entry;
  }
  console.log(`${entry_id}: transaction ended`);
  return {};
});

但是我在日志中注意到的是：

48: transaction started
48: before full check
47: transaction started
48: before updating items: 0
48: start update
47: before full check
47: before updating items: 0
47: start update
48: after updating items: 1
48: transaction ended
47: after updating items: 1
47: transaction ended

所以这意味着它们都同时被更新，更糟糕的是，他们看不到彼此的更新。

在更新时如何在数据库上放置锁？ -或者以其他方式防止出现这种情况？

交易繁忙时，交易是否能够顺利进行，不会阻止请求？

0 个答案: