MongoDB: Match multiple array elements

Question

I have a collection with next data:

db.MyCollection.insert({ 
        id: 1, 
        Location: [ 1, 1 ],
        Properties: [ { Type: 1, Value: "a" }, { Type: 2, Value: "b" }, { Type: 3, Value: "c" } ]
    });

db.MyCollection.insert({ 
        id: 2, 
        Location: [ 1, 2 ],
        Properties: [ { Type: 1, Value: "a" }, { Type: 2, Value: "a" }, { Type: 3, Value: "c" } ]
    });

db.MyCollection.insert({ 
        id: 3, 
        Location: [ 2, 1 ],
        Properties: [ { Type: 1, Value: "a" }, { Type: 3, Value: "b" }, { Type: 3, Value: "a" } ]
    });

db.MyCollection.insert({ 
        id: 4, 
        Location: [ 2, 2 ],
        Properties: [ { Type: 2, Value: "b" }, { Type: 2, Value: "a" }, { Type: 3, Value: "c" } ]
    });

db.MyCollection.ensureIndex({ Location: "2d"});
db.MyCollection.ensureIndex({ "Properties.Type": 1, "Properties.Value": 1});
db.MyCollection.ensureIndex({ Location: "2d", "Properties.Type": 1, "Properties.Value": 1});

What I want is to find all items (using any of above indexes) that:

1. match the Location
2. contain properties with (Type=1 and Value="a") and (Type=2 and Value="b")

Here is my query (it doesn't work, but looks close to the right one):

db.MyCollection.find(
{ 
    Location: { "$within": { "$center": [ [1, 1], 5 ] } },
    Properties: {
        $elemMatch: {
            $and: [
                { Type: 1, Value: "a" },
                { Type: 2, Value: "b" }
            ]
        }
    }
})

---

Update:

The $all query works better as there is a problem with the $and one (see my comment in the JohnnyHK answer). Thanks for help.

Answer 1

In a case like this where you want the docs that include a specific set of array elements, you can use the $all operator:

db.MyCollection.find(
{ 
    Location: { "$within": { "$center": [ [1, 1], 5 ] } },
    Properties: {
        $all: [
            {$elemMatch: { Type: 1, Value: "a" }},
            {$elemMatch: { Type: 2, Value: "b" }}
        ]
    }
})

To do it without the $all operator you could use:

db.MyCollection.find(
{ 
    Location: { "$within": { "$center": [ [1, 1], 5 ] } },
    $and: [
        { Properties: {
            $elemMatch: { Type: 1, Value: "a" }
        }},
        { Properties: {
            $elemMatch: { Type: 2, Value: "b" }
        }}
    ]
})