MongoDB-查找元素，其中字段至少等于数组中的一个值

Question

I have "reverse" problem to classic "find value(s) in array".

I get array of ids and I want to find elements, which has field with value in this array.

Example :

I have this in MyCollection

{a: 10}
{a: 7}
{a: 6}
{a: 15}

And I want to do query like this

MyCollection.find({a: [6,15])

Which would return me

[
    {a: 6},
    {a: 15}
]

Answer 1

Please try to use $in

> db.testdata.find({a: {$in: [6, 15]}})

With data

> db.testdata.find()
{ "_id" : ObjectId("56e800e2abc8519548297bc3"), "a" : 10 }
{ "_id" : ObjectId("56e800e5abc8519548297bc4"), "a" : 6 }
{ "_id" : ObjectId("56e800eaabc8519548297bc5"), "a" : 15 }

And test code

> db.testdata.find({a: {$in: [6, 15]}})
{ "_id" : ObjectId("56e800e5abc8519548297bc4"), "a" : 6 }
{ "_id" : ObjectId("56e800eaabc8519548297bc5"), "a" : 15 }

Answer 2

您可以$gte -更大， lt -小于

db.collection.find({ "a" : { $gte: 6, $lte: 15} } );