MongoDB query with $all in array

In MongoDB, $all is used to select the documents where the value of a field is an array that contains all the specified elements

Let us create a collection with documents −

> db.demo163.insertOne(
...    {
...       "ClientDetails": [{
...          "ClientName": "Chris"
...
...       }, {
...          "ClientName": "David"
...
...       }
...    ]
...
... }
... );
{
   "acknowledged" : true,
   "insertedId" : ObjectId("5e3686d49e4f06af551997c5")
}
> db.demo163.insertOne(
...    {
...       "ClientDetails": [{
...          "ClientName": "Mike"
...
...    }, {
...    "ClientName": "Sam"
...
...    }
... ]
...
... }
... );
{
   "acknowledged" : true,
   "insertedId" : ObjectId("5e3686d59e4f06af551997c6")
}
>
db.demo163.insertOne(
...    {
...       "ClientDetails": [{
...          "ClientName": "Robert"
...
...       }, {
...          "ClientName": "Sam"
...
...       }
...    ]
... }
... );
{
   "acknowledged" : true,
   "insertedId" : ObjectId("5e3686d59e4f06af551997c7")
}

Display all documents from a collection with the help of find() method −

> db.demo163.find();

This will produce the following output −

{ "_id" : ObjectId("5e3686d49e4f06af551997c5"), "ClientDetails" : [ { "ClientName" : "Chris" }, { "ClientName" : "David" } ] }
{ "_id" : ObjectId("5e3686d59e4f06af551997c6"), "ClientDetails" : [ { "ClientName" : "Mike" }, { "ClientName" : "Sam" } ] }
{ "_id" : ObjectId("5e3686d59e4f06af551997c7"), "ClientDetails" : [ { "ClientName" : "Robert" }, { "ClientName" : "Sam" } ] }

Following is the query for $all in MongoDB −

> db.demo163.find({"ClientDetails": {$all: [{"ClientName": "Mike"}, {"ClientName": "Sam"}]}});

This will produce the following output −

{ "_id" : ObjectId("5e3686d59e4f06af551997c6"), "ClientDetails" : [ { "ClientName" : "Mike" }, { "ClientName" : "Sam" } ] }