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Ignore NULL and UNDEFINED values while running a MongoDB query
To ignore NULL and UNDEFINED values, use $ne in MongoDB. Let us create a collection with documents −
> db.demo35.insertOne({"Name":"Chris"});
{
"acknowledged" : true,
"insertedId" : ObjectId("5e175e42cfb11e5c34d898d0")
}
> db.demo35.insertOne({"Name":null});
{
"acknowledged" : true,9
"insertedId" : ObjectId("5e175e46cfb11e5c34d898d1")
}
> db.demo35.insertOne({"Name":"Bob"});
{
"acknowledged" : true,
"insertedId" : ObjectId("5e175e4bcfb11e5c34d898d2")
}
> db.demo35.insertOne({"Name":undefined});
{
"acknowledged" : true,
"insertedId" : ObjectId("5e175e54cfb11e5c34d898d3")
}Display all documents from a collection with the help of find() method −
> db.demo35.find();
This will produce the following output −
{ "_id" : ObjectId("5e175e42cfb11e5c34d898d0"), "Name" : "Chris" }
{ "_id" : ObjectId("5e175e46cfb11e5c34d898d1"), "Name" : null }
{ "_id" : ObjectId("5e175e4bcfb11e5c34d898d2"), "Name" : "Bob" }
{ "_id" : ObjectId("5e175e54cfb11e5c34d898d3"), "Name" : undefined }Following is the query to use $new to ignore NULL values −
> db.demo35.find({"Name": {$ne: null}});This will produce the following output −
{ "_id" : ObjectId("5e175e42cfb11e5c34d898d0"), "Name" : "Chris" }
{ "_id" : ObjectId("5e175e4bcfb11e5c34d898d2"), "Name" : "Bob" }
Updated on: 02-Apr-2020
868 Views
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