To get connected clients in MongoDB, use currentOp() with the set value to true and you need to iterate array result set with the help of field client. Let us first implement currentOp> db.currentOp(true)Following is the output. Here the client is 127.0.0.1 since we are using localhost. The output displays ... Read More

This example describes how to use the HttpSession object to find out the creation time and the last-accessed time for a session. We would associate a new session with the request if one does not already exist.           Session Tracking       ... Read More

The C++ function std::unordered_multimap::operator=() assigns new contents to the unordered_multimap by replacing old ones and modifies size if necessary.Following is the declaration for std::unordered_multimap::operator=() function form std::unordered_map() header.C++11 (Syntax)unordered_multimap& operator=(const unordered_multimap& umm);Parametersumm - Another unordered_multimap object of same type.Return ValueReturns this pointer.Example Code#include #include using namespace std; int ... Read More

To check if field is a number in MongoDB, use the $type operator. Following is the syntaxdb.yourCollectionName.find({youtFieldName: {$type:"number"}}).pretty();Let us first create a collection with documents> db.checkIfFieldIsNumberDemo.insertOne({"StudentName":"John", "StudentAge":23}); {    "acknowledged" : true,    "insertedId" : ObjectId("5c9ec75dd628fa4220163b83") } >db.checkIfFieldIsNumberDemo.insertOne({"StudentName":"Chris", "StudentMathScore":98, "StudentCountryName":"US"}); {    "acknowledged" : true,    "insertedId" : ObjectId("5c9ec77cd628fa4220163b84") } ... Read More

The application object is direct wrapper around the ServletContext object for the generated Servlet and in reality an instance of a javax.servlet.ServletContext object.This object is a representation of the JSP page through its entire lifecycle. This object is created when the JSP page is initialized and will be removed when ... Read More

To reset the primary key to 1 after deleting the data, use the following syntaxalter table yourTableName AUTO_INCREMENT=1; truncate table yourTableName;After doing the above two steps, you will get the primary key beginning from 1.To understand the above concept, let us create a table. The query to create a table ... Read More

To rename column name in a collection, you can use $rename operator. Following is the syntaxdb.yourCollectionName.update({}, {$rename: {'yourOldColumName': 'yourNewColumnName'}}, false, true);Let us first create a collection with documents:> db.renamingColumnNameDemo.insertOne({"StudentName":"Larry", "Age":23}); {    "acknowledged" : true,    "insertedId" : ObjectId("5c9ee2c6d628fa4220163b9a") } > db.renamingColumnNameDemo.insertOne({"StudentName":"Sam", "Age":26}); {    "acknowledged" : true,    "insertedId" ... Read More

In this article we will see how to fill the whole memory by writing a simple C++ program. Here the logic is very simple. We shall create new integer variables by using the dynamic memory allocation. If we create some variables again and again, it will fill the entire primary ... Read More

You can use update command along with forEach() for large collection. Let us first create a collection with documents>db.addingNewPropertyDemo.insertOne({"StudentName":"John", "StudentAge":23, "CountryName":"US"}); {    "acknowledged" : true,    "insertedId" : ObjectId("5ca1e61866324ffac2a7dc56") } >db.addingNewPropertyDemo.insertOne({"StudentName":"David", "StudentAge":21, "CountryName":"AUS"}); {    "acknowledged" : true,    "insertedId" : ObjectId("5ca1e62366324ffac2a7dc57") } >db.addingNewPropertyDemo.insertOne({"StudentName":"Bob", "StudentAge":21, "CountryName":"UK"}); {    "acknowledged" ... Read More

To search a value in Java Decade Tuple, use the contains() method. It returns a booleans value i.e. TRUE if the element exist, else FALSE.Let us first see what we need to work with JavaTuples. To work with Decade class in JavaTuples, you need to import the following packageimport org.javatuples.Decade;Note ... Read More