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Articles on Trending Technologies
Technical articles with clear explanations and examples
Check how many rows are in a MySQL database table?
To know how many rows are in a ySQL database table, you need to use aggregate function COUNT(*).The syntax is as followsSELECT COUNT(*) FROM yourTableName;To understand the above syntax, let us create a table. The query to create a table is as followsmysql> create table CountRowsDemo - > ( - > Id int NOT NULL AUTO_INCREMENT PRIMARY KEY, - > Name varchar(20) - > ); Query OK, 0 rows affected (0.78 sec)Insert some records in the table using insert command.The query is as followsmysql> insert into CountRowsDemo(Name) values(NULL); Query OK, 1 row affected (0.15 sec) mysql> ...
Read MoreHow to use length () in Android textview?
This example demonstrate about How to use length () in Android textview.Step 1 − Create a new project in Android Studio, go to File ⇒ New Project and fill all required details to create a new project.Step 2 − Add the following code to res/layout/activity_main.xml. In the above code, we have taken the name as Edit text, when user click on button it will take data and check length of entered value is 0 or more than zero than returns last index of “sai”.Step 3 − Add the following code to src/MainActivity.javapackage com.example.myapplication; ...
Read MoreIn a MySQL schema, what is the meaning of "AUTO_INCREMENT=3
In MySQL, AUTO_INCREMENT=3 tells that the inserted record will start from 3 not the default 1. Let us first create a sample table and set auto increment to 3:mysql> create table Auto_incrementDemo -> ( -> Id int NOT NULL AUTO_INCREMENT PRIMARY KEY, -> Name varchar(20) -> )AUTO_INCREMENT=3; Query OK, 0 rows affected (0.52 sec)Following is the query to insert some records in the table using insert command:mysql> INSERT INTO Auto_incrementDemo(Name) values('John'); Query OK, 1 row affected (0.12 sec) mysql> INSERT INTO Auto_incrementDemo(Name) values('Larry'); Query OK, 1 row affected (0.15 sec) mysql> INSERT INTO Auto_incrementDemo(Name) ...
Read MoreJava Program to convert java.util.Date to any local date in certain timezone
First, set the Date and ZoneId −Date date = new Date(); ZoneId zone = ZoneId.systemDefault();Now convert the java.util.date to localdate −date.toInstant().atZone(zone).toLocalDate() date.toInstant().atZone(zone).toLocalTime() date.toInstant().atZone(zone).getHour() date.toInstant().atZone(zone).getMinute() date.toInstant().atZone(zone).getSecond()Exampleimport java.time.ZoneId; import java.util.Date; public class Demo { public static void main(String[] args) { Date date = new Date(); ZoneId zone = ZoneId.systemDefault(); System.out.println("LocalDate = "+date.toInstant().atZone(zone).toLocalDate()); System.out.println("LocalTime= "+date.toInstant().atZone(zone).toLocalTime()); System.out.println("Hour = "+date.toInstant().atZone(zone).getHour()); System.out.println("Minute = "+date.toInstant().atZone(zone).getMinute()); System.out.println("Seconds = "+date.toInstant().atZone(zone).getSecond()); } }OutputLocalDate = 2019-04-18 LocalTime= 23:25:09.708 Hour = 23 Minute = 25 Seconds = 9
Read MoreRename all tables and columns to lower case in MySQL?
You can achieve this with the help of INFORMATION_SCHEMA.COLUMNS. The syntax is as follows −SELECT CONCAT('ALTER TABLE ', TABLE_NAME, ' CHANGE `', COLUMN_NAME, '` `', LOWER(COLUMN_NAME), '` ', COLUMN_TYPE, ';') AS anyAliasName FROM INFORMATION_SCHEMA.COLUMNS WHERE TABLE_SCHEMA = ‘yourDatabaseName’;Now use the database which has two tables. The database name is as follows “bothinnodbandmyisam”. This database is having the following tables −employeestudentThe description of the employee table is as follows −mysql> desc employee;The following is the output. Let’s say we have the following columns in the employee table which are not in lowercase −+--------------+-------------+------+-----+---------+-------+ | Field | Type ...
Read MoreCan MySQL concatenate strings with ||?
Yes, you can concatenate strings with || in MySQL with the help of sql_mode. Set the sql_mode to PIPES_AS_CONCAT.The syntax is as followsset sql_mode=PIPES_AS_CONCAT;The following is the syntax to concat with the help of ||.SELECT ‘yourValue' || yourColumName AS anyAliasName FROM yourTableName;To understand the above syntax, let us create a table. The query to create a table is as followsmysql> create table PipeConcatDemo - > ( - > Name varchar(20) - > ); Query OK, 0 rows affected (0.93 sec)Insert some records in the table using insert command.The query is as followsmysql> insert into PipeConcatDemo values('Larry'); Query ...
Read MoreHow to use replace () in Android textview?
This example demonstrate about How to use replace () in Android textview.Step 1 − Create a new project in Android Studio, go to File ⇒ New Project and fill all required details to create a new project.Step 2 − Add the following code to res/layout/activity_main.xml. In the above code, we have taken name as Edit text, when user click on button it will take data and replace all a values withStep 3 − Add the following code to src/MainActivity.javapackage com.example.myapplication; import android.os.Bundle; import android.support.v7.app.AppCompatActivity; import android.view.View; import android.widget.Button; import android.widget.EditText; import android.widget.TextView; ...
Read MoreMySQL query to select one specific row and another random row?
To select one specific row and another random row, you can use ORDER BY and RAND(). Let us first create a sample table:mysql> create table oneSpecificRowAndOtherRandom -> ( -> Id int NOT NULL AUTO_INCREMENT PRIMARY KEY, -> Name varchar(20) -> ); Query OK, 0 rows affected (0.72 sec)Following is the query to insert some records in the table using insert command:mysql> insert into oneSpecificRowAndOtherRandom(Name) values('Larry'); Query OK, 1 row affected (0.56 sec) mysql> insert into oneSpecificRowAndOtherRandom(Name) values('Sam'); Query OK, 1 row affected (0.13 sec) mysql> insert into oneSpecificRowAndOtherRandom(Name) values('Mike'); Query OK, 1 row affected ...
Read MoreC++ Program to Implement Modular Exponentiation Algorithm
This is a C++ program to implement Modular Exponentiation Algorithm.AlgorithmBegin function modular(): // Arguments: base, exp, mod. // Body of the function: initialize res = 1 while (exp > 0) if (exp mod 2 == 1) res= (res * base) % mod exp = exp left shift 1 base = (base * base) % mod return res. EndExample#include using namespace std; long long modular(long long base, long long exp, int mod) { long long res = 1; while (exp > 0) { if (exp % 2 == 1) res= (res * base) % mod; exp = exp >> 1; base = (base * base) % mod; } return res; } int main() { long long b, e; int mod; coutb; coute; coutmod; cout
Read MoreHow to know whether your training is effective or not?
The first day of employment for any employee: be a fresher, experienced person, or managerial, will always start off with a training session. The day-long training completes with numerous amount of information, but does so much effort made by the Organization is worth the money invested in the training sessions. We all agree that training is the key to a well-motivated, knowledgeable, and efficient staff.Here we are going to discuss the top reasons on why the training sessions do not help your employees, and why this whole expenditure on training is not fruitful. We will check out the conditions because of ...
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