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Select special fields rather than all in MongoDB
For this, simply use find(). Set the fields you don’t want to select to 0. Let us create a collection with documents −
> db.demo269.insertOne({StudentId:101,StudentSubject:"MySQL"});
{
"acknowledged" : true,
"insertedId" : ObjectId("5e481caa1627c0c63e7dbab4")
}
> db.demo269.insertOne({StudentId:102,StudentSubject:"Java"});
{
"acknowledged" : true,
"insertedId" : ObjectId("5e481cb11627c0c63e7dbab5")
}
> db.demo269.insertOne({StudentId:103,StudentSubject:"MongoDB"});
{
"acknowledged" : true,
"insertedId" : ObjectId("5e481cb21627c0c63e7dbab6")
}
> db.demo269.insertOne({StudentId:104,StudentSubject:"C"});
{
"acknowledged" : true,
"insertedId" : ObjectId("5e481cb21627c0c63e7dbab7")
}Display all documents from a collection with the help of find() method −
> db.demo269.find();
This will produce the following output −
{ "_id" : ObjectId("5e481caa1627c0c63e7dbab4"), "StudentId" : 101, "StudentSubject" : "MySQL" }
{ "_id" : ObjectId("5e481cb11627c0c63e7dbab5"), "StudentId" : 102, "StudentSubject" : "Java" }
{ "_id" : ObjectId("5e481cb21627c0c63e7dbab6"), "StudentId" : 103, "StudentSubject" : "MongoDB" }
{ "_id" : ObjectId("5e481cb21627c0c63e7dbab7"), "StudentId" : 104, "StudentSubject" : "C" }Following is the query to select only specific fields rather than all −
> db.demo269.find({},{"StudentId":0,_id:0});This will produce the following output −
{ "StudentSubject" : "MySQL" }
{ "StudentSubject" : "Java" }
{ "StudentSubject" : "MongoDB" }
{ "StudentSubject" : "C" }
Updated on: 31-Mar-2020
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