Display the undefined and exact MongoDB document records

For this, use the forEach(). To display the values, use printjson(). Let us create a collection with documents −

> db.demo496.insertOne({"Name":"David","CountryName":"US"});{
   "acknowledged" : true,
   "insertedId" : ObjectId("5e84b04ab0f3fa88e22790ce")
}
> db.demo496.insertOne({"Name":"John","CountryName":"AUS"});{
   "acknowledged" : true,
   "insertedId" : ObjectId("5e84b054b0f3fa88e22790cf")
}
> db.demo496.insertOne({"Name":"Robert","CountryName":"UK"});{
   "acknowledged" : true,
   "insertedId" : ObjectId("5e84b05db0f3fa88e22790d0")
}

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

> db.demo496.find();

This will produce the following output −

{ "_id" : ObjectId("5e84b04ab0f3fa88e22790ce"), "Name" : "David", "CountryName" : "US" }
{ "_id" : ObjectId("5e84b054b0f3fa88e22790cf"), "Name" : "John", "CountryName" : "AUS" }
{ "_id" : ObjectId("5e84b05db0f3fa88e22790d0"), "Name" : "Robert", "CountryName" : "UK" }

Following is the query to display undefined for documents −

> db.demo496.find({}).forEach( (done, notDone) => { printjson(notDone); });

This will produce the following output −

undefined
undefined
undefined

Following is the query to display the documents with.forEach() −

> db.demo496.find({}).forEach( (done, notDone) => { printjson(done); });

This will produce the following output −

{
   "_id" : ObjectId("5e84b04ab0f3fa88e22790ce"),
   "Name" : "David",
   "CountryName" : "US"
}
{
   "_id" : ObjectId("5e84b054b0f3fa88e22790cf"),
   "Name" : "John",
   "CountryName" : "AUS"
}
{
   "_id" : ObjectId("5e84b05db0f3fa88e22790d0"),
   "Name" : "Robert",
   "CountryName" : "UK"
}

AmitDiwan

Updated on: 2020-05-13T05:38:59+05:30

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