To extract the subarray value in MongoDB, you can use $elemMatch projection operator.
Let us first create a collection with documents −
> db.extractSubArrayDemo.insertOne(
... {
... _id: 101,
... "clientName":"Larry",
... "ClientDetails":
... [
... {
... "ClientProjectName":"Online Game",
... "DeveloperTeamSize": 10
... },
... {
... "ClientProjectName":"Pig Dice Game",
... "DeveloperTeamSize": 12
... },
... {
... "ClientProjectName":"Web Student Tracker",
... "DeveloperTeamSize": 11
... }
...
... ]
... }
... );
{ "acknowledged" : true, "insertedId" : 101 }Following is the query to display all documents from the collection with the help of find() method −
> db.extractSubArrayDemo.find().pretty();
This will produce the following output −
{
"_id" : 101,
"clientName" : "Larry",
"ClientDetails" : [
{
"ClientProjectName" : "Online Game",
"DeveloperTeamSize" : 10
},
{
"ClientProjectName" : "Pig Dice Game",
"DeveloperTeamSize" : 12
},
{
"ClientProjectName" : "Web Student Tracker",
"DeveloperTeamSize" : 11
}
]
}Following is the query to extract subarray value in MongoDB −
> db.extractSubArrayDemo.find({ '_id': 101 },{ _id: 0, ClientDetails:
{ $elemMatch: {ClientProjectName: 'Pig Dice Game' } }}).pretty();This will produce the following output −
{
"ClientDetails" : [
{
"ClientProjectName" : "Pig Dice Game",
"DeveloperTeamSize" : 12
}
]
}
