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How to find only a single document satisfying the criteria in MongoDB?
To find only a single document, use findOne() in MongoDB. Let us create a collection with documents −
> db.demo116.insertOne({"EmployeeId":101,"EmployeeName":"John"});
{
"acknowledged" : true,
"insertedId" : ObjectId("5e2eff98d8f64a552dae635b")
}
> db.demo116.insertOne({"EmployeeId":102,"EmployeeName":"Bob"});
{
"acknowledged" : true,
"insertedId" : ObjectId("5e2eff9fd8f64a552dae635c")
}
> db.demo116.insertOne({"EmployeeId":103,"EmployeeName":"David"});
{
"acknowledged" : true,
"insertedId" : ObjectId("5e2effa5d8f64a552dae635d")
}
> db.demo116.insertOne({"EmployeeId":102,"EmployeeName":"Mike"});
{
"acknowledged" : true,
"insertedId" : ObjectId("5e2effb7d8f64a552dae635e")
}Display all documents from a collection with the help of find() method −
> db.demo116.find();
This will produce the following output −
{ "_id" : ObjectId("5e2eff98d8f64a552dae635b"), "EmployeeId" : 101, "EmployeeName" : "John" }
{ "_id" : ObjectId("5e2eff9fd8f64a552dae635c"), "EmployeeId" : 102, "EmployeeName" : "Bob" }
{ "_id" : ObjectId("5e2effa5d8f64a552dae635d"), "EmployeeId" : 103, "EmployeeName" : "David" }
{ "_id" : ObjectId("5e2effb7d8f64a552dae635e"), "EmployeeId" : 102, "EmployeeName" : "Mike" }Following is the query to find only a single document in MongoDB −
> db.demo116.findOne({"EmployeeId":102});This will produce the following output −
{
"_id" : ObjectId("5e2eff9fd8f64a552dae635c"),
"EmployeeId" : 102,
"EmployeeName" : "Bob"
}
Updated on: 30-Mar-2020
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