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How to work with variables in MongoDB query
To use variables, work with var in MongoDB. Let us create a collection with documents −
> db.demo107.insertOne({"Name":"Chris"});
{
"acknowledged" : true,
"insertedId" : ObjectId("5e2ee1b19fd5fd66da214471")
}
> db.demo107.insertOne({"Name":"Bob"});
{
"acknowledged" : true,
"insertedId" : ObjectId("5e2ee1b49fd5fd66da214472")
}
> db.demo107.insertOne({"Name":"David"});
{
"acknowledged" : true,
"insertedId" : ObjectId("5e2ee1b89fd5fd66da214473")
}Display all documents from a collection with the help of find() method −
> db.demo107.find();
This will produce the following output −
{ "_id" : ObjectId("5e2ee1b19fd5fd66da214471"), "Name" : "Chris" }
{ "_id" : ObjectId("5e2ee1b49fd5fd66da214472"), "Name" : "Bob" }
{ "_id" : ObjectId("5e2ee1b89fd5fd66da214473"), "Name" : "David" }Following is the query to use variable in MongoDB −
> var firstName="Bob";
> db.demo107.find({"Name":firstName});This will produce the following output −
{ "_id" : ObjectId("5e2ee1b49fd5fd66da214472"), "Name" : "Bob" }
Updated on: 30-Mar-2020
3K+ Views
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