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Articles on Trending Technologies
Technical articles with clear explanations and examples
Python Program to find the sum of a Series 1/1! + 2/2! + 3/3! + 4/4! +…….+ n/n!
In this article, we will learn about the solution and approach to solve the given problem statement.Problem statement −Given an integer input n, we need to find the sum of a Series 1/1! + 2/2! + 3/3! + 4/4! +…….+ n/n!Here we are implementing for loop, therefore, we get O(n) as the time complexity.Here to reach the efficiency we calculate factorial within the same loop.Here we frame a sumofseries function as described below −Example Live Demodef sumOfSeries(num): res = 0 fact = 1 for i in range(1, num+1): fact *= i res ...
Read MorePopulate null columns in a MySQL table and set values
For this, you can use IS NULL property. Let us first create a table −mysql> create table DemoTable ( ProductPrice int, ProductQuantity int, TotalAmount int ); Query OK, 0 rows affected (1.22 sec)Insert some records in the table using insert command −mysql> insert into DemoTable(ProductPrice, ProductQuantity) values(100, 2); Query OK, 1 row affected (0.17 sec) mysql> insert into DemoTable(ProductPrice, ProductQuantity) values(500, 4); Query OK, 1 row affected (0.23 sec) mysql> insert into DemoTable(ProductPrice, ProductQuantity) values(1000, 10); Query OK, 1 row affected (0.21 sec)Display all records from the table using select statement −mysql> select *from DemoTable;This will produce ...
Read MoreHow to make a pair of columns unique in MySQL?
To make a pair of columns unique, use UNIQUE with ALTER TABLE command. Following is the syntax −alter table yourTableName add unique yourUniqueName(yourColumnName1, yourColumnName2, ...N);Let us first create a table −mysql> create table DemoTable ( StudentId int NOT NULL AUTO_INCREMENT PRIMARY KEY, StudentFirstName varchar(100), StudentLastName varchar(100), StudentAge int, StudentPhoneNumber varchar(20) ); Query OK, 0 rows affected (0.81 sec)Following is the query to make a pair of unique columns in MySQL −mysql> alter table DemoTable add unique DemoTable_unique_StudentFirstName_StudentPhoneNumber(StudentFirstName, StudentPhoneNumber); Query OK, 0 rows affected (0.40 sec) Records: 0 Duplicates: 0 Warnings: 0Insert some records in the ...
Read MorePython Program to find the area of a circle
In this article, we will learn about the solution and approach to solve the given problem statement.Problem statement −Given the radius of a circle, we need to find a circle.The area of a circle can simply be evaluated using the following formula.Area = Pi*r*rLet’s see the implementation below −Example Live Demodef findArea(r): PI = 3.142 return PI * (r*r); # Driver method print("Area is %.6f" % findArea(5));OutputArea is 78.550000All variables and functions are declared in the global scope as shown in the figure below.ConclusionIn this article, we learned about the approach to find whether it is possible to make ...
Read MoreTribonacci Word in C++
The Tribonacci Word is a sequence of digits. This is similar to the Fibonacci Words. Tribonacci Word is constructed by repeated concatenation of three previous stringsT(n) = T(n - 1) + T(n - 2) + T(n - 3)The first few strings to start, are {1, 12, 1213} So the next one will be 1213 + 12 + 1 = 1213121Algorithmtribonacci_word(n): Begin first := 1, second := 12, third := 1213 print first, second, third for i in range 3 to n, do temp := third third := third + second + ...
Read MoreResolve ERROR 1064 (42000) that occurred after using varchar (without providing the size)
Let us first see when this situation can arise. Create a table and set column name with datatype but without the size −mysql> create table DemoTable ( Id int NOT NULL AUTO_INCREMENT PRIMARY KEY, FirstName varchar, LastName varchar ); ERROR 1064 (42000): You have an error in your SQL syntax; check the manual that corresponds to your MySQL server version for the right syntax to use near ', LastName varchar )' at line 4You can correct the above error by providing the size for varchar data type like varchar(100). The same will fix the issue.Let’s fix it ...
Read MoreWhile creating a MySQL table use the reserved keyword ‘Key’
To use the reserved keyword ‘Key’, use the concept of the backtick symbol. Here, for our example, I am using the column name key which needs a backtick symbol around the column name.Let us first create a table −mysql> create table DemoTable ( `Key` int ); Query OK, 0 rows affected (0.67 sec)Insert some records in the table using insert command −mysql> insert into DemoTable values(100); Query OK, 1 row affected (0.16 sec) mysql> insert into DemoTable values(101); Query OK, 1 row affected (0.55 sec) mysql> insert into DemoTable values(110); Query OK, 1 row affected (0.28 sec) mysql> insert ...
Read MoreMySQL SUM function to add decimal values
Let us first create a table −mysql> create table DemoTable ( Money DECIMAL(7, 2) ); Query OK, 0 rows affected (0.58 sec)Insert some records in the table using insert command −mysql> insert into DemoTable values(100.67); Query OK, 1 row affected (0.16 sec) mysql> insert into DemoTable values(199.33); Query OK, 1 row affected (0.12 sec) mysql> insert into DemoTable values(500); Query OK, 1 row affected (0.19 sec) mysql> insert into DemoTable values(400); Query OK, 1 row affected (0.14 sec) mysql> insert into DemoTable values(800); Query OK, 1 row affected (0.14 sec)Display all records from the table using select statement −mysql> ...
Read MoreTetranacci Numbers in C++
Here we will see how to generate the Tetranacci numbers using C++. The Tetranacci numbers are similar to the Fibonacci numbers, but here we are generating a term by adding four previous terms. Suppose we want to generate T(n), then the formula will be like below −T(n) = T(n - 1) + T(n - 2) + T(n - 3) + T(n - 4)The first few numbers to start, are {0, 1, 1, 2}Algorithmtetranacci(n): Begin first := 0, second := 1, third := 1, fourth := 2 print first, second, third, fourth for i in range n – ...
Read MoreMySQL query to select a record with two exact values?
For this, you can use GROUP BY HAVING clause. Let us first create a table −mysql> create table DemoTable ( Id int NOT NULL AUTO_INCREMENT PRIMARY KEY, Value int ); Query OK, 0 rows affected (0.52 sec)Insert some records in the table using insert command −mysql> insert into DemoTable(Value) values(600); Query OK, 1 row affected (0.14 sec) mysql> insert into DemoTable(Value) values(600); Query OK, 1 row affected (0.14 sec) mysql> insert into DemoTable(Value) values(800); Query OK, 1 row affected (0.12 sec) mysql> insert into DemoTable(Value) values(800); Query OK, 1 row affected (0.09 sec)Display all records from the table ...
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