$all (original) (raw)

$all

The $all operator selects the documents where the value of a field matches all specified values. The matched documents can either contain a field with a value that is an array containing all the specified elements, or a field with a single value matching the specified element.

You can use $all for deployments hosted in the following environments:

• MongoDB Atlas: The fully managed service for MongoDB deployments in the cloud
• MongoDB Enterprise: The subscription-based, self-managed version of MongoDB
• MongoDB Community: The source-available, free-to-use, and self-managed version of MongoDB

To specify an $all expression, use the following prototype:

{ <field>: { $all: [ <value1> , <value2> ... ] } }

The $all is equivalent to an $and operation of the specified values; i.e. the following statement:

{ tags: { $all: [ "ssl" , "security" ] } }

is equivalent to:

{ $and: [ { tags: "ssl" }, { tags: "security" } ] }

When passed an array of a nested array (e.g. [ [ "A" ] ] ),$all matches documents where the field contains the nested array as an element (e.g. field: [ [ "A" ], ... ]), or the field equals the nested array (e.g. field: [ "A" ]).

For example, consider the following query:

db.articles.find( { tags: { $all: [ [ "ssl", "security" ] ] } } )

The query is equivalent to:

db.articles.find( { $and: [ { tags: [ "ssl", "security" ] } ] } )

which is equivalent to:

db.articles.find( { tags: [ "ssl", "security" ] } )

As such, the $all expression matches documents where thetags field is an array that contains the nested array [ "ssl", "security" ] or is an array that equals the nested array:

tags: [ [ "ssl", "security" ], ... ]

tags: [ "ssl", "security" ]

When passed an empty array, $all matches no documents.

The following examples use the inventory collection that contains the documents:

{

   _id: ObjectId("5234cc89687ea597eabee675"),

   code: "xyz",

   tags: [ "school", "book", "bag", "headphone", "appliance" ],

   qty: [

          { size: "S", num: 10, color: "blue" },

          { size: "M", num: 45, color: "blue" },

          { size: "L", num: 100, color: "green" }

        ]

}

{

   _id: ObjectId("5234cc8a687ea597eabee676"),

   code: "abc",

   tags: [ "appliance", "school", "book" ],

   qty: [

          { size: "6", num: 100, color: "green" },

          { size: "6", num: 50, color: "blue" },

          { size: "8", num: 100, color: "brown" }

        ]

}

{

   _id: ObjectId("5234ccb7687ea597eabee677"),

   code: "efg",

   tags: [ "school", "book" ],

   qty: [

          { size: "S", num: 10, color: "blue" },

          { size: "M", num: 100, color: "blue" },

          { size: "L", num: 100, color: "green" }

        ]

}

{

   _id: ObjectId("52350353b2eff1353b349de9"),

   code: "ijk",

   tags: [ "electronics", "school" ],

   qty: [

          { size: "M", num: 100, color: "green" }

        ]

}

The following operation uses the $all operator to query theinventory collection for documents where the value of the tagsfield is an array whose elements include appliance, school, andbook:

db.inventory.find( { tags: { $all: [ "appliance", "school", "book" ] } } )

The above query returns the following documents:

{

   _id: ObjectId("5234cc89687ea597eabee675"),

   code: "xyz",

   tags: [ "school", "book", "bag", "headphone", "appliance" ],

   qty: [

          { size: "S", num: 10, color: "blue" },

          { size: "M", num: 45, color: "blue" },

          { size: "L", num: 100, color: "green" }

        ]

}

{

   _id: ObjectId("5234cc8a687ea597eabee676"),

   code: "abc",

   tags: [ "appliance", "school", "book" ],

   qty: [

          { size: "6", num: 100, color: "green" },

          { size: "6", num: 50, color: "blue" },

          { size: "8", num: 100, color: "brown" }

        ]

}

If the field contains an array of documents, you can use the$all with the $elemMatch operator.

The following operation queries the inventory collection for documents where the value of the qty field is an array whose elements match the $elemMatch criteria:

db.inventory.find( {

                     qty: { $all: [

                                    { "$elemMatch" : { size: "M", num: { $gt: 50} } },

                                    { "$elemMatch" : { num : 100, color: "green" } }

                                  ] }

                   } )

The query returns the following documents:

{

   "_id" : ObjectId("5234ccb7687ea597eabee677"),

   "code" : "efg",

   "tags" : [ "school", "book"],

   "qty" : [

             { "size" : "S", "num" : 10, "color" : "blue" },

             { "size" : "M", "num" : 100, "color" : "blue" },

             { "size" : "L", "num" : 100, "color" : "green" }

           ]

}

{

   "_id" : ObjectId("52350353b2eff1353b349de9"),

   "code" : "ijk",

   "tags" : [ "electronics", "school" ],

   "qty" : [

             { "size" : "M", "num" : 100, "color" : "green" }

           ]

}

The $all operator exists to support queries on arrays. But you may use the $all operator to select against a non-arrayfield, as in the following example:

db.inventory.find( { "qty.num": { $all: [ 50 ] } } )

However, use the following form to express the same query:

db.inventory.find( { "qty.num" : 50 } )

Both queries will select all documents in the inventorycollection where the value of the num field equals 50.

Note

In most cases, MongoDB does not treat arrays as sets. This operator provides a notable exception to this approach.

For additional examples on querying arrays, see:

• Query an Array
• Query an Array of Embedded Documents

For additional examples on querying, seeQuery Documents.

See also: