查询Mongodb中的子文档数组

Question

I have a collection of documents that goes like this:

{
  name: "Whatever 1".
  distances: [
    {name: "first distance", distance: 3000},   
    {name: "another distance", distance: 8000},
  ]
},
{
  name: "Whatever 2".
  distances: []
},
{
  name: "Whatever 3".
  distances: [
    {name: null, distance: 6000},   
  ]
},
{
  name: "Whatever 4".
  distances: [
    {name: "hello", distance: 100000},   
  ]
},

I need to get all the documents that contains a distance in a given range.

Example: If I query for distance greater than 5000 and smaller than 9000 , I want to get documents "Whatever 1" and "Whatever 3"

How can I do this?

Answer 1

您可以使用$elemMatch为distances数组的单个子文档指定范围条件：

db.col.find({ distances: { $elemMatch: { distance: { $gt: 5000, $lt: 9000 } } } })