查询Mongodb中的子文档数组

Question

我有一个像这样的文档集合：

{
  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},   
  ]
},

我需要获取包含给定范围内距离的所有文档。

示例：如果我查询大于5000且小于9000距离，我想获得文档"Whatever 1"和"Whatever 3"

我怎样才能做到这一点？

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 } } } })