MongoDB批量运算符，如果不存在则插入 [英] MongoDB bulk operator, insert if not exists

问题描述

我正在使用MongoDB批量操作来插入文档.

I'm using the MongoDB bulk operation to insert documents.

我想做的就是插入，仅在找不到文档的情况下-如果找到文档(即upsert)，我不想更新.

What I'd like to do is insert, only if no document is found - I don't want to update if it is found (i.e., upsert).

任何想法如何做到这一点?

Any ideas how to do this?

但是，即使在这种情况下:

However, even in this case:

var obj = {
 item: 'test'
}

bulk.find({ item: {$ne : obj.item}}).upsert().updateOne(obj);
bulk.execute();

这似乎并没有实际插入任何东西(如果找不到的话).

This doesn't seem to actually insert anything if not found.

我想对此进行更新以澄清更多信息.

I wanted to update this to clarify a bit more.

我正在尝试使用批量api执行两项操作，一项是更新，一项是插入.

There are two operations I'm trying to perform, using bulk api, one is to update and one is to insert.

文档如下:

{
  item: 'test',
  categories: [{
     name: 'one',
     attr: 'two'
  }]
}

我想做的是，如果找不到项目值，则插入obj.但是，如果找到它，则如果没有找到categories.name，则将$push类别对象作为categories数组.如果找到该文档且该类别存在，则什么也不做.

What I'd like to do is if the item value is not found, then insert the obj. However, if it is found, then if categories.name is not found, $push the category object to the categories array. If the document is found and the category exists, do nothing.

推荐答案

您想要保持相同的更新操作，但要更改查询.从文档:

What you'd want is to maintain the same update operation but change the query. From the documentation:

Bulk.find(<query>).upsert().update(<update>); Bulk.find(<query>).upsert().updateOne(<update>); Bulk.find(<query>).upsert().replaceOne(<replacement>);

将upsert选项设置为true，如果

With the upsert option set to true, if no matching documents exist for the Bulk.find() condition, then the update or the replacement operation performs an insert. If a matching document does exist, then the update or replacement operation performs the specified update or replacement.

更改查询以查找满足以下条件的文档:

Change the query to look for documents that satisfy the condition:

var obj = { item: 'test' };

bulk.find(obj).upsert().updateOne({ $setOnInsert: obj });
bulk.execute();

在上面，如果确实存在匹配的文档，则使用

In the above, if the a matching document does exist, then the update with $setOnInsert does nothing as the update operation does not result in an insert, having found a document that matches the query.

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