MongoDB $all

Summary: in this tutorial, you’ll learn how to use the MongoDB $all operator to select documents.

Introduction to the MongoDB $all operator

The $all is an array query operator that allows you to find the documents where the value of a field is an array that contains all the specified elements.

The $all operator has the following syntax:

{ <arrayField>: { $all: [element1, element2, ...]} }

If the array followed the $all operator is empty, then the $all operator matches no documents.

When the array followed the $all operator contains a single element, you should use the contain expression instead:

{ <arrayField>: element1 }

$all and $and

The following expression that uses the $all operator:

{ arrayField: {$all: [element1, element2]} }

is equivalent to the following expression that use the $and operator:

{ $and: [{ arrayField: element1}, {arrayField: element2} ]}

MongoDB $all operator examples

We’ll use the following products collection:

db.products.insertMany([
	{ "_id" : 1, "name" : "xPhone", "price" : 799, "releaseDate" : ISODate("2011-05-14T00:00:00Z"), "spec" : { "ram" : 4, "screen" : 6.5, "cpu" : 2.66 }, "color" : [ "white", "black" ], "storage" : [ 64, 128, 256 ] },
	{ "_id" : 2, "name" : "xTablet", "price" : 899, "releaseDate" : ISODate("2011-09-01T00:00:00Z"), "spec" : { "ram" : 16, "screen" : 9.5, "cpu" : 3.66 }, "color" : [ "white", "black", "purple" ], "storage" : [ 128, 256, 512 ] },
	{ "_id" : 3, "name" : "SmartTablet", "price" : 899, "releaseDate" : ISODate("2015-01-14T00:00:00Z"), "spec" : { "ram" : 12, "screen" : 9.7, "cpu" : 3.66 }, "color" : [ "blue" ], "storage" : [ 16, 64, 128 ] },
	{ "_id" : 4, "name" : "SmartPad", "price" : 699, "releaseDate" : ISODate("2020-05-14T00:00:00Z"), "spec" : { "ram" : 8, "screen" : 9.7, "cpu" : 1.66 }, "color" : [ "white", "orange", "gold", "gray" ], "storage" : [ 128, 256, 1024 ] },
	{ "_id" : 5, "name" : "SmartPhone", "price" : 599, "releaseDate" : ISODate("2022-09-14T00:00:00Z"), "spec" : { "ram" : 4, "screen" : 9.7, "cpu" : 1.66 }, "color" : [ "white", "orange", "gold", "gray" ], "storage" : [ 128, 256 ] }
])

1) Using MongoDB $all operator to match values

The following example uses the $all operator to query the products collection for documents where the value of the color field is an array that includes "black" and "white":

db.products.find({
    color: {
        $all: ["black", "white"]
    }
}, {
    name: 1,
    color: 1
})

It returned the following documents. Notice that the order of elements in the array is not important.

{ "_id" : 1, "name" : "xPhone", "color" : [ "white", "black" ] }
{ "_id" : 2, "name" : "xTablet", "color" : [ "white", "black", "purple" ] }

Functionally speaking, the above query is equivalent to the following query that uses the $and operator:

db.products.find({
    $and: [
        {color: "black"},
        {color: "white"}
    ]
}, {
    name: 1,
    color: 1
})

Summary

• Use the $all operator to select the documents where the value of a field is an array that contains all the specified elements.