Adapter Pattern in C++

sudhir sharma
Updated on 04-Oct-2019 06:51:58

304 Views

An adapter pattern is used to convert the interface of a class into an interface that is expected by the client. An adapter helps the programmer to make its classes work together and make sure the user requirement is fulfilled by making incompatible interfaces completable.let's understand a bit more about the adapter pattern. The concept of adapter is taken from the real world. as in the real world We use adapters to connect things that are incompatible with each other. let's take an example, in modern day smartphones the 3.5 mm jack for earphones is missing, so the brands have ... Read More

Delete Rows Older Than 14 Days in MySQL

AmitDiwan
Updated on 04-Oct-2019 06:51:08

1K+ Views

To delete, use MySQL DELETE. However, to get records older than 14 days, subtract the current date with date interval of 14 days. The syntax for the same is shown below −delete from yourTableName where yourColumnName< (curdate() - interval 14 day);Let us first create a table −mysql> create table DemoTable (    Id int NOT NULL AUTO_INCREMENT PRIMARY KEY,    DueDate date ); Query OK, 0 rows affected (0.50 sec)Insert some records in the table using insert command −mysql> insert into DemoTable(DueDate) values('2019-08-20'); Query OK, 1 row affected (0.15 sec) mysql> insert into DemoTable(DueDate) values('2019-08-19'); Query OK, 1 row affected ... Read More

3-Digit Osiris Number in C

sudhir sharma
Updated on 04-Oct-2019 06:50:08

168 Views

Osiris Number is a number whose value is equal to the sum of values of all number formed by adding all the permutations of its own digits.In this problem, we are given a 3-Digit number N, and we will check weather the number N is an Osiris number.Let’s take an example, Input : N = 132 Output : 132ExplanationAll sub-samples of N : 13 , 12, 21, 23 ,32 31.Sum = 13+12+21+23+32+31 = 132To do this, we have a formula to check whether the given number is Osiris number or not.Example Live Demo#include int main() {    int n = ... Read More

Create Table Inside MySQL Stored Procedure and Insert Record

AmitDiwan
Updated on 04-Oct-2019 06:49:06

603 Views

Create a table inside the stored procedure and use INSERT as well −mysql> DELIMITER // mysql> CREATE PROCEDURE create_TableDemo(id int,name varchar(100),age int)    BEGIN    CREATE TABLE DemoTable    (       ClientId int NOT NULL,       ClientName varchar(30),       ClientAge int,       PRIMARY KEY(ClientId)    );    INSERT INTO DemoTable VALUES(id,name,age);    SELECT *FROM DemoTable;    END // Query OK, 0 rows affected (0.17 sec) mysql> DELIMITER ;Call the stored procedure using CALL command −mysql> CALL create_TableDemo(100,'Robert',28);This will produce the following output −+----------+------------+-----------+ | ClientId | ClientName | ClientAge | +----------+------------+-----------+ |      100 | Robert     |        28 | +----------+------------+-----------+ 1 row in set (0.76 sec) Query OK, 0 rows affected (0.78 sec)

Angular Sweep Algorithm in C++

sudhir sharma
Updated on 04-Oct-2019 06:48:06

574 Views

The algorithm to find the maximum number of points that can be enclosed in a circle of a given radius. This means that for a circle of radius r and a given set of 2-D points, we need to find the maximum number of points that are enclosed (lying inside the circle not on its edges) by the circle.For, this is the most effective method is the angular sweep algorithm.AlgorithmThere are nC2 points given in the problem, we need to find the distance between each of these points.Take an arbitrary point and get the maximum number of points lying in ... Read More

Find Last Date from Records with Date Values in MySQL

AmitDiwan
Updated on 04-Oct-2019 06:47:01

290 Views

To get the last date i.e. the latest, use aggregate function MAX() with a subquery. Let us first create a table −mysql> create table DemoTable (    Id int NOT NULL AUTO_INCREMENT PRIMARY KEY,    ExpiryDate date ); Query OK, 0 rows affected (1.40 sec)Insert some records in the table using insert command −mysql> insert into DemoTable(ExpiryDate) values('2018-12-31'); Query OK, 1 row affected (0.15 sec) mysql> insert into DemoTable(ExpiryDate) values('2019-09-01'); Query OK, 1 row affected (0.14 sec) mysql> insert into DemoTable(ExpiryDate) values('2019-09-01'); Query OK, 1 row affected (0.07 sec) mysql> insert into DemoTable(ExpiryDate) values('2016-08-30'); Query OK, 1 row affected (0.13 ... Read More

Is it Compulsory to Set Primary Key for Auto Increment Value?

AmitDiwan
Updated on 04-Oct-2019 06:45:40

199 Views

Yes, use AUTO_INCREMENT with PRIMARY KEY. Let us first create a table −mysql> create table DemoTable (    EmployeeId int NOT NULL AUTO_INCREMENT,    EmployeeName varchar(40),    EmployeeAge int,    PRIMARY KEY(EmployeeId),    UNIQUE KEY(EmployeeName, EmployeeAge) ); Query OK, 0 rows affected (0.96 sec)Let us check the table description of the table −mysql> desc DemoTable;This will produce the following output −+--------------+-------------+------+-----+---------+----------------+ | Field        | Type        | Null | Key | Default | Extra          | +--------------+-------------+------+-----+---------+----------------+ | EmployeeId   | int(11)     | NO   | PRI | NULL   ... Read More

Find Average of First Three Values in MySQL

AmitDiwan
Updated on 04-Oct-2019 06:42:16

249 Views

For this, you can use a subquery. Let us first create a table −mysql> create table DemoTable (    Score int ); Query OK, 0 rows affected (0.62 sec)Insert some records in the table using insert command −mysql> insert into DemoTable values(80); Query OK, 1 row affected (0.13 sec) mysql> insert into DemoTable values(45); Query OK, 1 row affected (0.13 sec) mysql> insert into DemoTable values(55); Query OK, 1 row affected (0.33 sec) mysql> insert into DemoTable values(78); Query OK, 1 row affected (0.20 sec) mysql> insert into DemoTable values(88); Query OK, 1 row affected (0.13 sec)Display all records from ... Read More

MySQL Query to Display Record with Maximum Count Values in a Group

AmitDiwan
Updated on 04-Oct-2019 06:40:23

406 Views

For this, use the GROUP BY HAVING clause. Let us first create a table −mysql> create table DemoTable (    Value int ); Query OK, 0 rows affected (0.54 sec)Insert some records in the table using insert command −mysql> insert into DemoTable values(88); Query OK, 1 row affected (0.22 sec) mysql> insert into DemoTable values(88); Query OK, 1 row affected (0.10 sec) mysql> insert into DemoTable values(88); Query OK, 1 row affected (0.09 sec) mysql> insert into DemoTable values(99); Query OK, 1 row affected (0.09 sec) mysql> insert into DemoTable values(99); Query OK, 1 row affected (0.09 sec) mysql> insert ... Read More

Basic String C-Style String Function in C++ STL

sudhir sharma
Updated on 04-Oct-2019 06:39:11

142 Views

The basic_string c_str function that returns a pointer to an array of characters that is terminated using null character. It is an inbuilt method that has the value of a string that has null character termination.Syntax to define a c_str function in C++ −const Char ptr* c_str() constAbout the functionIt is an inbuilt method for the c++ STL library. No parameters can be passed to the method. It returns a char pointer. This pointer points to NULL terminated character array.Example Live Demo#include #include using namespace std; int main() {    string s = "I Love Tutorials Point";    int ... Read More

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