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How can I search a collection to find a nested value in one of its documents in MongoDB?
For this, use double underscore( __) in find(). Let us first create a collection with documents −
> db.nestedDemo.insertOne({"Information":{"__StudentName":"John Smith"}}); { "acknowledged" : true, "insertedId" : ObjectId("5e06f39125ddae1f53b621f0") } > db.nestedDemo.insertOne({"Information":{"__StudentName":"John Doe"}}); { "acknowledged" : true, "insertedId" : ObjectId("5e06f39e25ddae1f53b621f1") } > db.nestedDemo.insertOne({"Information":{"__StudentName":"Chris Brown"}}); { "acknowledged" : true, "insertedId" : ObjectId("5e06f3a625ddae1f53b621f2") }
Following is the query to display all documents from a collection with the help of find() method −
> db.nestedDemo.find().pretty();
This will produce the following output −
{ "_id" : ObjectId("5e06f39125ddae1f53b621f0"), "Information" : { "__StudentName" : "John Smith" } } { "_id" : ObjectId("5e06f39e25ddae1f53b621f1"), "Information" : { "__StudentName" : "John Doe" } } { "_id" : ObjectId("5e06f3a625ddae1f53b621f2"), "Information" : { "__StudentName" : "Chris Brown" } }
Here is the query to search a collection to find a nested value in one of its documents in MongoDB −
> db.nestedDemo.find({"Information.__StudentName":"John Doe"});
This will produce the following output −
{ "_id" : ObjectId("5e06f39e25ddae1f53b621f1"), "Information" : { "__StudentName" : "John Doe" } }
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