TechHeap

To query like JOINS between 2 collections in mongodb, we need to use $aggregate. Lets see the example:   I have 2 collections, one is Emp...

To compare 2 fields of a document while querying in mongodb, we need to use $where. Lets see the example to compare 2 fields of a documen...

To update specific records of an array field in MongoDB, we can achieve that by using JavaScript with Mongo query. Below are the two ways t...

We cannot directly use update method to update the field with same document's another field. We need to first iterate the data and then...

To connect MongoDB through JAVA, we will use MongoClient and to fetch and iterate data we will use MongoCollection and FindIterable classe...

$exists is an element query operator that can be use to check the existense of any field in a document. Syntax: { field: { $exists: } }...

MongoDB is a no-sql database, which can contain huge data in collections. Due to non relational /un-structered data, it takes load of time ...

Like SQL statements we can use LIKE keywords in Mongo as well. We can query mongdb with LIKE search. We can restrict LIKE search as we do i...

Execute MongoDB queries from command prompt we can run mongodb queries from command prompt as well. Run command prompt in administrator m...

How to print specific data from Collection or document using Javascript in MongoDB Mongo supports javascript queries to handle the data a...

Mongo Allows to have bulk updates using following operation: db.collection.initializeOrderedBulkOp() Initializes and returns a new B...