MongoDB查询以从集合中删除重复的文档 [英] MongoDB query to remove duplicate documents from a collection

问题描述

我从搜索框中获取数据，然后使用常规插入查询将MongoDB作为文档插入到MongoDB中.数据以以下格式存储在单词"cancer"的集合中，格式为唯一的"_id".

I take data from a search box and then insert into MongoDB as a document using the regular insert query. The data is stored in a collection for the word "cancer" in the following format with unique "_id".

{
  "_id": {
    "$oid": "553862fa49aa20a608ee2b7b"
  },
  "0": "c",
  "1": "a",
  "2": "n",
  "3": "c",
  "4": "e",
  "5": "r"
}

每个文档都有一个单词，其存储方式与上述相同.我有很多这样的文件.现在，我想从集合中删除重复的文档.我无法找到一种方法来做到这一点.救救我.

Each document has a single word stored in the same format as above. I have many documents as such. Now, I want to remove the duplicate documents from the collection. I am unable to figure out a way to do that. Help me.

推荐答案

在mongo shell中的简单解决方案:`

an easy solution in mongo shell: `

use your_db
db.your_collection.createIndex({'1': 1, '2': 1, '3': 1, etc until you reach maximum expected letter count}, {unique: true, dropDups: true, sparse:true, name: 'dropdups'})
db.your_collection.dropIndex('dropdups')

注释:

• 如果您有许多文档，则希望此过程花费很长时间 时间
• 注意，这将删除现有文档，最好先克隆您的收藏集，然后在此处尝试.

• if you have many documents expect this procedure to take very long time
• be careful this will remove documents in place, better clone your collection first and try it there.

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