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You can use aggregate function count along with if() for this. To understand the concept, let us create a table. The query to create a table is as followsmysql> create table CountOccurrencesDemo -> ( -> Id int NOT NULL AUTO_INCREMENT PRIMARY KEY, -> TechnicalSubject varchar(100) -> ); Query OK, 0 rows affected (0.68 sec)Now you can insert some records in the table using insert command. The query is as followsmysql> insert into CountOccurrencesDemo(TechnicalSubject) values('Java'); Query OK, 1 row affected (0.14 sec) mysql> insert into CountOccurrencesDemo(TechnicalSubject) values('MongoDB'); Query OK, 1 row affected (0.13 sec) mysql> insert into ... Read More
The hash code value of the LocalDate can be obtained using the hashCode() method in the LocalDate class in Java. This method requires no parameters and it returns the hash code value of the LocalDate.A program that demonstrates this is given as follows −Example Live Demoimport java.time.*; public class Main { public static void main(String[] args) { LocalDate ld = LocalDate.parse("2019-02-15"); System.out.println("The LocalDate is: " + ld); System.out.println("The hash code is: " + ld.hashCode()); } }OutputThe LocalDate ... Read More
The toArray() method is used to return an array containing all the elements in this list in proper sequence.The syntax is as follows −Object[] toArray()To work with CopyOnWriteArrayList class, you need to import the following package −import java.util.concurrent.CopyOnWriteArrayList;The following is an example to implement CopyOnWriteArrayList class toArray() method in Java−Example Live Demoimport java.util.Arrays; import java.util.concurrent.CopyOnWriteArrayList; public class Demo { public static void main(String[] args) { CopyOnWriteArrayList arrList = new CopyOnWriteArrayList(); arrList.add(220); arrList.add(250); arrList.add(400); ... Read More
You can use the aggregate framework to get a particular element from the MongoDB array. To understand the concept, let us create a collection with the document. The query to create a collection with the document is as follows −> db.getParticularElement.insertOne({"InstructorName":"Larry", "InstructorTechnicalSubject":["Java", "C", "C++", "MongoDB", "MySQL", "SQL Server"]}); { "acknowledged" : true, "insertedId" : ObjectId("5c7ee027559dd2396bcfbfb1") }Display all documents from a collection with the help of find() method. The query is as follows −> db.getParticularElement.find().pretty();The following is the output −{ "_id" : ObjectId("5c7ee027559dd2396bcfbfb1"), "InstructorName" : "Larry", "InstructorTechnicalSubject" : [ "Java", ... Read More
Let us first create a tablemysql> create table orderByAFunctionDemo -> ( -> Id int NOT NULL AUTO_INCREMENT PRIMARY KEY, -> FirstNumber int, -> SecodNumber int -> ); Query OK, 0 rows affected (0.44 sec)Insert some records in the table using insert command. The query is as follows −mysql> insert into orderByAFunctionDemo(FirstNumber, SecodNumber) values(10, 4); Query OK, 1 row affected (0.11 sec) mysql> insert into orderByAFunctionDemo(FirstNumber, SecodNumber) values(45, 78); Query OK, 1 row affected (0.17 sec) mysql> insert into orderByAFunctionDemo(FirstNumber, SecodNumber) values(23, 10); Query OK, 1 row affected (0.12 sec) mysql> insert into orderByAFunctionDemo(FirstNumber, SecodNumber) values(67, ... Read More
This is a C++ Program to Find Size of the Largest Independent Set (LIS) in a Given a Binary Tree.AlgorithmBegin. Create a structure n to declare data d, a left child pointer l and a right child pointer r. Call a function max() to return maximum between two integers. Create a function LIS() to return the size of the largest independent set in a given binary tree. Calculate size excluding the current node int size_excl = LIS(root->l) + LIS(root->r) Calculate size including the current node int size_incl = 1; if (root->l) ... Read More
This is a C++ Program to implement Network_Flow problem using Ford Fulkerson algorithm.Algorithms:Begin function bfs() returns true if there is path from source s to sink t in the residual graph which indicates additional possible flow in the graph. End Begin function fordfulkarson() return maximum flow in given graph: A) initiate flow as 0. B) If there is an augmenting path from source to sink, add the path to flow. C) Return flow. EndExample Code#include #include #include #include #define n 7 using namespace std; bool bfs(int g[n][n], int s, int ... Read More
Following is the syntax to retrieve the documents whose values end with a particular character in MongoDBdb.yourCollectionName.find({yourFieldName: {$regex: "yourEndingCharacter$"}}).pretty();Let us first create a collection with documents>db.retrieveDocumentsWithEndsWithParticularCharacterDemo.insertOne({"StudentName":"Adam", "StudentAge":25, "StudentCountryName":"LAOS"}); { "acknowledged" : true, "insertedId" : ObjectId("5c9c45b32d66697741252456") } >db.retrieveDocumentsWithEndsWithParticularCharacterDemo.insertOne({"StudentName":"Sam", "StudentAge":24, "StudentCountryName":"ANGOLA"}); { "acknowledged" : true, "insertedId" : ObjectId("5c9c45c02d66697741252457") } >db.retrieveDocumentsWithEndsWithParticularCharacterDemo.insertOne({"StudentName":"Robert", "StudentAge":21, "StudentCountryName":"AUS"}); { "acknowledged" : true, "insertedId" : ObjectId("5c9c45cb2d66697741252458") } >db.retrieveDocumentsWithEndsWithParticularCharacterDemo.insertOne({"StudentName":"Chris", "StudentAge":20, "StudentCountryName":"UK"}); { "acknowledged" : true, "insertedId" : ObjectId("5c9c45d92d66697741252459") } >db.retrieveDocumentsWithEndsWithParticularCharacterDemo.insertOne({"StudentName":"Larry", "StudentAge":23, "StudentCountryName":"US"}); { "acknowledged" : true, "insertedId" : ObjectId("5c9c45eb2d6669774125245a") }Following is the query to display all documents from a collection ... Read More
Let us first create a string array −String[] strArr = new String[] { "r", "p", "v", "y", "s", "q" };Now, use Arrays.sort() to get the subset. Use the following to sort only from the index range 2 to 6.Arrays.sort(strArr, 2, 6);Example Live Demoimport java.util.Arrays; public class Demo { public static void main(String[] args) { String[] strArr = new String[] { "r", "p", "v", "y", "s", "q" }; Arrays.sort(strArr, 2, 6); System.out.println("Sorted subset of array elements from index 2 to 6..."); for (int a = 0; a < strArr.length; ... Read More
In this section we will see what is the compound literals in C. The compound literals are introduced in C99 standard in C. Using this feature, it can create unnamed objects. In the following example we will see how to use compound literal to generate object without any name.Example#include struct point { int x; int y; }; void display_point(struct point pt) { printf("(%d,%d)", pt.x, pt.y); } main() { display_point((struct point) {10, 20}); }Output(10,20)