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Articles on Trending Technologies
Technical articles with clear explanations and examples
MySQL query to alphabetize records and count the duplicates?
For this, use both GROUP BY and ORDER BY clause. Let us first create a table −mysql> create table DemoTable ( StudentId int NOT NULL AUTO_INCREMENT PRIMARY KEY, StudentGrade char(1) ); Query OK, 0 rows affected (0.87 sec)Insert some records in the table using insert command −mysql> insert into DemoTable(StudentGrade) values('A'); Query OK, 1 row affected (0.13 sec) mysql> insert into DemoTable(StudentGrade) values('F'); Query OK, 1 row affected (0.14 sec) mysql> insert into DemoTable(StudentGrade) values('C'); Query OK, 1 row affected (0.28 sec) mysql> insert into DemoTable(StudentGrade) values('A'); Query OK, 1 row affected (0.23 sec) mysql> insert ...
Read MoreHow many bits are used to represent Unicode, ASCII, UTF-16, and UTF-8 characters in java?
In general, data is stored in a computer in the form of bits (1 or, 0). There are various coding schemes available specifying the set of bytes represented by each character.ASCII − Stands for American Standards Code for Information Interchange. It is developed by American standards association and is the mostly used coding system. It represents characters using 7 bits and has includes 128 characters: upper and lowercase Latin alphabet, the numbers 0-9, and some extra characters).Unicode (UTF) − Stands for Unicode Translation Format. It is developed by The Unicode Consortium. if you want to create documents that use characters ...
Read MoreImplementation of a Falling Matrix in C++
We have seen falling matrix scene in different films etc. Here we will see how to write a C++ program to do like that.To solve this problem, we have to care about these steps.Define width of the matrixTwo successive characters may or may not have same amount of gap between themA certain amount of delay between printing each line to visualize the falling effect.Example#include #include #include #include #include #include const int wd = 70; //set the width of the matrix window const int flipsPerLine =5; //five flips for the boolean array 'alternate' const int sleepTime = 50; //it will take ...
Read MoreHow to resize an array in Java?
An array cannot be resized dynamically in Java. One approach is to use java.util.ArrayList(or java.util.Vector) instead of a native array.Another approach is to re-allocate an array with a different size and copy the contents of the old array to the new array.Example:class ResizableArray { public static void main (String[] args) { int[] a = {1, 2, 3}; a = (int[])resizeArray(a, 5); a[3] = 4; a[4] = 5; for (int i=0; i 0) System.arraycopy(oldArray, 0, newArray, 0, preserveLength); return newArray; } } Output:1 2 3 4 5
Read MoreResolve Syntax error near "ORDER BY order DESC" in MySQL?
The word order is a reserved order in MySQL and you have used it in the query. To get rid of the syntax error, you need to use backticks(` `) around the order.The correct syntax is as follows −select *from yourTableName ORDER BY `order` DESC;Let us first create a table −mysql> create table DemoTable ( `order` int ); Query OK, 0 rows affected (0.58 sec)Insert some records in the table using insert command −mysql> insert into DemoTable values(89); Query OK, 1 row affected (0.19 sec) mysql> insert into DemoTable values(67); Query OK, 1 row affected (0.13 sec) ...
Read MoreHow to create a GridLayout with rows and columns in Java?
While creating a GridLayout, you need to set the rows and columns as parenthesis. A GridLayout is used to create a layout the specified number of rows and columns.Let’s say we have a GridLayout, with 1 row and 4 columns −GridLayout layout = new GridLayout(1, 4);The following is an example to create a GridLayout with rows and columns −Examplepackage my; import java.awt.Color; import java.awt.Dimension; import java.awt.FlowLayout; import java.awt.Font; import java.awt.GridLayout; import javax.swing.JButton; import javax.swing.JFrame; import javax.swing.JLabel; import javax.swing.JPanel; import javax.swing.JTextArea; import javax.swing.WindowConstants; public class SwingDemo { public static void main(String[] args) { JFrame frame = new ...
Read Moreregex_error in C++
The regex library has different methods and features related to regular expressions. Here we will see some regex_errors. These are also present at regex library. During executing some regular expressions, we get some errors. That errors are mentioned here.FlagsErrorserror_collateIn the Regex, the names having invalid collation.error_ctypeIn the Regex, there is an invalid character class name.error_stackNot enough memory to determine regex can be matched or not.error_spaceConvert into Finite State Machine, when memory is insufficienterror_badrepeatThe string has repeat specifier ( *?+{) that was not preceded by a valid regular expression.error_complexityThe complexity of an attempted match against a regex exceeded a pre-set levelerror_rangeContaining ...
Read MoreCan we update a row with the highest ID in a single MySQL query?
Yes, we can do that. Let us first create a table −mysql> create table DemoTable ( ID int, GameScore int ); Query OK, 0 rows affected (0.55 sec)Insert some records in the table using insert command −mysql> insert into DemoTable values(15, 848747); Query OK, 1 row affected (0.12 sec) mysql> insert into DemoTable values(13, 909049); Query OK, 1 row affected (0.13 sec) mysql> insert into DemoTable values(34, 98474646); Query OK, 1 row affected (0.15 sec) mysql> insert into DemoTable values(31, 948474); Query OK, 1 row affected (0.27 sec)Display all records from the table using select statement ...
Read MoreC++ tricks for competitive programming (for C++ 11)?
Here we will see some good tricks of C++ programming language that can help us in different area. Like if we want to participate in some competitive programming events, then these tricks will help us to reduce the time for writing codes. Let us see some of these examples one by one.Checking whether a number is odd or even without using % operator. This trick is simple. We can perform bitwise AND operation with the number and 1. If the result is non-zero then this is odd, otherwise this is even. The logic is too simple. All odd numbers have ...
Read MoreWhat does buffer flush means in C++ ?
The buffer flush is used to transfer of computer data from one temporary storage area to computers permanent memory. If we change anything in some file, the changes we see on the screen are stored temporarily in a buffer.In C++, we can explicitly have flushed to force the buffer to be written. If we use std::endl, it adds one new line character, and also flush it. If this is not used, we can explicitly use flush. In the following program at first no flush is used. Here we are trying to print the numbers, and wait for one seconds. For ...
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