You can use distinct() method in MongoDB to get distinct record values. The syntax is as follows −db.yourCollectionName.distinct(“yourFieldName”);To understand the above syntax, let us create a collection with document. The query to create a collection with document is as follows −> db.distinctRecordDemo.insertOne({"StudentId":1, "StudentName":"John", "StudentAge":21}); {    "acknowledged" : true,   ... Read More

To sort in MongoDB, you can use the sort() method.Case 1 − Sort in ascending order. The syntax is as follows −db.yourCollectionName.find().sort({yourField:1});Case 2 − Sort in descending order. The syntax is as follows −db.yourCollectionName.find().sort({yourField:-1});To understand the concept, let us create a collection with the document. The query to create a ... Read More

A reference variable is an alias, that is, another name for an already existing variable. Once a reference is initialized with a variable, either the variable name or the reference name may be used to refer to the variable.References vs PointersReferences are often confused with pointers but three major differences ... Read More

To get the list of all values of certain fields in MongoDB, you can use distinct(). The syntax is as follows −db.yourCollectionName.distinct( "yourFieldName");To understand the above syntax, let us create a collection with the document. The query to create a collection with a document is as follows −> db.listAllValuesOfCeratinFieldsDemo.insertOne({"ListOfValues":[10, 20, ... Read More

To get the highest value of a column in MongoDB, you can use sort() along with limit(1). The syntax is as follows −db.yourCollectionName.find().sort({"yourFieldName":-1}).limit(1);To understand the above syntax, let us create a collection with the document. The query to create a collection with a document is as follows −> db.gettingHighestValueDemo.insertOne({"Value":1029}); { ... Read More

The B-tree is a generalization of a binary search tree in that a node can have more than two children. It is basically a self-balancing tree data structure that maintains sorted data and allows sequential access, searches, insertions, and deletions in logarithmic time.Here is a C++ program to implement B ... Read More

A Hamiltonian cycle is a Hamiltonian Path such that there is an edge (in graph) from the last vertex to the first vertex of the Hamiltonian Path. It is in an undirected graph is a path that visits each vertex of the graph exactly once.Functions and purposesBegin    1. function ... Read More

The peek() method of the LongStream class returns a stream with the elements of this stream, additionally performing the provided action on each element as elements are consumed from the resulting stream.The syntax is as follows −LongStream peek(LongConsumer action)Here, LongConsumer represents an operation that accepts a single long-valued argument and ... Read More

Here is a C++ Program to Implement Cartesian Tree.AlgorithmBegin    class CarTree to declare the functions:       min() = To find index of the minimum element in array:    if (arr[i] < min)       min = arr[i]       minind = i       ... Read More

If you want to list all collections from a particular database then you need to switch the database first. The query is as follows −> use sample; switched to db sample > db.getCollectionNames();The following is the output −[    "copyThisCollectionToSampleDatabaseDemo",    "deleteDocuments",    "deleteDocumentsDemo",    "deleteInformation",    "employee",    "internalArraySizeDemo", ... Read More