You can use $lt operator for this. Let us create a collection with documents − , Display all documents from a collection with the help of find() method. The query is as follows − , This will produce the following output − , Following is the query to find all objects created before specified date − , This will produce the following output − ,

To remove item from array, you can use $pull operator. Let us create a collection with documents − , Display all documents from a collection with the help of find() method. The query is as follows − , This will produce the following output − , Following is the query to remove item from an array − , In the above query, we have removed “Java”. Let us now di.....

To save new Date() in MongoDB, you can use new ISODate(). Let us create a collection with documents − , Display all documents from a collection with the help of find() method − , This will produce the following output − ,

Use the concept of length to count distinct value. Following is the syntax − , Let us create a collection with documents − , Display all documents from a collection with the help of find() method − , This will produce the following output − , Following is the query to count distinct value − , This will produce the following output − ,

You can use $indexOfArray operator for this. Let us create a collection with documents − , Display all documents from a collection with the help of find() method − , This will produce the following output − , Following is the query to get index of given element in an array field in MongoDB − , This will produce the following output − , Following is the query to.....

Use $unset operator to unset an attribute. Let us first create a collection with documents − , Following is the query to display all documents from the collection with the help of find() method − , This will produce the following output − , Following is the query to unset an attribute from a single array element. The attribute “StudentCountryName” with value &l.....

You can use $not operator along with $type for this. Let us first create a collection with documents − , Following is the query to display all documents from the collection with the help of find() method − , This will produce the following output − , Following is the query to find the highest numeric value of a column − , This will produce the following output &minus.....

You can use dot(.) notation to read a specific key-value pair from MongoDB collection. Let us first create a collection with documents − , Following is the query to display all documents from the collection with the help of find() method − , This will produce the following output − , Following is the query to read a specific key-value pair from a MongoDB collection −.....

You can use aggregate framework along with $setUnion operator. Let us first create a collection with documents − , Following is the query to display all documents from the collection with the help of find() method − , This will produce the following output − , Following is the query to remove duplicate values inside a list in MongoDB − , This will produce the followi.....

To extract the subarray value in MongoDB, you can use $elemMatch projection operator. Let us first create a collection with documents − , Following is the query to display all documents from the collection with the help of find() method − , This will produce the following output − , Following is the query to extract subarray value in MongoDB − , This will produce the.....