如何通过使用嵌入式文档的值有效地从JSON文档数组中访问JSON文档？

Question

I need a method/strategy in JavaScript to access documents from a JSON array. I need something that works kind of like $elemMatch in MongoDB Shell.

The data is in the following format:

[
    { 
      a : '1',
      b : '2',
      c : '3'
    },
    { 
      a : '4',
      b : '5',
      c : '6'
    },
    {...},
    {...}
]

So all the documents have the same keys and I need to access the 'c' value when I have the 'a' value.

Is any way to do this efficiently in JavaScript, ie without having to loop through the entire array? This will form part of a much larger query function and performance is extremely important.

Answer 1

You can use the find command with nested data. Check this link for javascript syntax and the accepted answer in this link for a general idea on what you're trying to do.

Edit: For javascript, you could try to use the match command with the aggregation pipeline framework ( more info here ).