You can use $all operator. Let us first create a collection with documents −> db.subsetOfAnArrayDemo.insertOne({"StudentProgrammingSkills":    ["Java", "MongoDB", "MySQL", "C++", "Data Structure", "Algorithm", "Python", "Oracle", "SQL Server"]}); {    "acknowledged" : true,    "insertedId" : ObjectId("5cb9d1e1895c4fd159f80804") }Following is the query to display all documents from the collection with the help ... Read More

You need to use date type to work with date before 1970 because date stores value from 1000 to 9999. A date type can be used when you need to work with date part only not for time purpose.MySQL gives the data in the following format. The format is as ... Read More

An immutable copy of a duration where the duration is negated can be obtained using the negated() method in the Duration class in Java. This method requires no parameters and it returns the negated duration. Also, if a numeric overflow occurs the ArithmeticException is thrown.A program that demonstrates this is ... Read More

Let us first see what we need to work with JavaTuples. To work with Quartet class in JavaTuples, you need to import the following package −import org.javatuples.Quartet;Note − Steps to download and run JavaTuples program If you are using Eclipse IDE to run Quartet Class in JavaTuples, then Right Click ... Read More

When you restart your application, i.e., web server, this will reset your application variable and your hit counter will reset to zero. To avoid this loss, consider the following points −Define a database table with a single count, let us say hitcount. Assign a zero value to it.With every hit, ... Read More

The MonthDay object can be queried as required using the query method in the MonthDay class in Java. This method requires a single parameter i.e. the query to be invoked and it returns the result of the query.A program that demonstrates this is given as follows −Example Live Demoimport java.time.*; import ... Read More

To delete a MongoDB field and value, you can use $unset operator. Let us first create a collection with documents −> db.deleteFieldDemo.insertOne({"FirstName":"John", "LastName":"Smith"}); {    "acknowledged" : true,    "insertedId" : ObjectId("5cb9fb767219729fde21ddad") } > db.deleteFieldDemo.insertOne({"FirstName":"David", "LastName":"Miller"}); {    "acknowledged" : true,    "insertedId" : ObjectId("5cb9fb837219729fde21ddae") } > db.deleteFieldDemo.insertOne({"FirstName":"Carol", "LastName":"Taylor"}); { ... Read More

The iteration through Pair in JavaTuples is the same as you may have seen in Java Arrays collection.Let us first see what we need to work with JavaTuples. To work with Pair class in JavaTuples, you need to import the following package −import org.javatuples.Pair;Note − Steps to download and run ... Read More

JSP makes this job easy by providing you a mechanism where you can make a webpage in such a way that it would refresh automatically after a given interval.The simplest way of refreshing a Webpage is by using the setIntHeader() method of the response object. Following is the signature of ... Read More

The duration can be obtained in a 24 hour format using the ofDays() method in the Duration class in Java. This method requires a single parameter i.e. the number of days and it returns the duration in a 24 hour format. If the capacity of the duration is exceeded, then ... Read More