Article Categories
- All Categories
-
Data Structure
-
Networking
-
RDBMS
-
Operating System
-
Java
-
MS Excel
-
iOS
-
HTML
-
CSS
-
Android
-
Python
-
C Programming
-
C++
-
C#
-
MongoDB
-
MySQL
-
Javascript
-
PHP
-
Economics & Finance
Articles by Chandu yadav
Page 76 of 81
Biggest value from two or more fields in MySQL?
To know the biggest value from two or more fields, use the function GREATEST() from MySQL.The syntax is as follows −SELECT GREATEST(MAX(yourColumnName1), MAX(yourColumnName2), ...............MAX(yourColumnName2) ) from yourTableName;Let us understand the above concept by creating a table with more than two columns −mysql> create table GreatestOfTwoOrMore -> ( -> Marks1 int, -> Marks2 int, -> Marks3 int -> ); Query OK, 0 rows affected (0.57 sec)Here is the query to insert records in a table −mysql> insert into GreatestOfTwoOrMore values(23, 78, 89); Query OK, 1 row ...
Read MoreIs there a way to know your current username in MySQL?
Yes, you can use the method CURRENT_USER() to know the current username in MySQL.The above method returns the username that can be used to authenticate the client connection.The query is as follows −mysql> select CURRENT_USER();The following is the output −+----------------+ | CURRENT_USER() | +----------------+ | root@% | +----------------+ 1 row in set (0.00 sec)Or you can use USER() method from MySQL. The query is as follows −mysql> select user();Here is the output −+----------------+ | user() | +----------------+ | root@localhost | +----------------+ 1 row in set (0.00 sec)
Read MoreHow to change the default charset of a MySQL table?
To change the default charset of a MySQL table, you can use the below syntax. The syntax is as follows −alter table yourTableName convert to character set yourCharsetName;Let us create a table and apply the above syntax to change the default charset. The query to create a table −mysql> create table CharsetDemo -> ( -> Id int, -> Name varchar(200), -> Age int -> ); Query OK, 0 rows affected (0.73 sec)Now you can change the charset of a table. The following is the query ...
Read MoreWhere does MySQL store database files?
To know where MySQL store database files, you can use the variable @@datadir. The query is as follows −mysql> select @@datadir;The following is the output that displays the path −+---------------------------------------------+ | @@datadir | +---------------------------------------------+ | C:\ProgramData\MySQL\MySQL Server 8.0\Data\ | +---------------------------------------------+ 1 row in set (0.00 sec)Here is the snapshot where MySQL store database files i.e. the same path we got above −Now, let us verify whether ...
Read MoreAdd 30 days to a value in a MySQL table?
To add 30 days to a value in the table, you can use ADDDATE() function with UPDATE command. The syntax is as follows:UPDATE yourTableName SET yourDateColumnName=ADDDATE(yourDateColumnName, INTERVAL 30 DAY);To understand the above syntax, let us create a table. The query to create a table is as follows:mysql> create table Add30DayDemo -> ( -> Id int NOT NULL AUTO_INCREMENT, -> ShippingDate date, -> PRIMARY KEY(ID) -> ); Query OK, 0 rows affected (0.76 sec)Insert some records in the table using insert command. The query is as follows:mysql> insert into Add30DayDemo(ShippingDate) values('2019-02-04'); Query OK, 1 row affected ...
Read MoreCan MySQL INT type be non-zero NULL?
You can set the INT column to value NULL.The column INT type a nullable column. The syntax is as follows:INSERT INTO yourTableName(yourIntColumnName) values(NULL);To understand the above syntax, let us create a table. The query to create a table is as follows:mysql> create table nullableIntDemo -> ( -> Id int NOT NULL AUTO_INCREMENT, -> Price int, -> PRIMARY KEY(Id) -> ); Query OK, 0 rows affected (0.80 sec)Insert the record as NULL for a int column ‘Price’. The query is as follows:mysql> insert into nullableIntDemo(Price) values(NULL); Query OK, 1 row affected (0.11 sec) mysql> insert into ...
Read MoreAre quotes around tables and columns in a MySQL query really necessary?
If your table name or column name are any reserved words then you need to use quotes around table name and column name in a MySQL query. You need to use backticks around table name and column name. The syntax is as follows:SELECT *FROM `table` where `where`=condition;Here is the query to create a table without quotes with reserved words. You will get an error since they are predefined reserved words. The error is as follows:mysql> create table table -> ( -> where int -> ); ERROR 1064 (42000): You have an error in your SQL syntax; check ...
Read MoreHow to verify enter number is phone number or not using regex in android?
This example demonstrates how to verify enter number is phone number or not, using regex in android.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 Edit text and text view. when the user clicks on text view, it will take data from edit text and valid the data.Step 3 - Add the following code to src/MainActivity.javapackage com.example.andy.myapplication; import android.os.Build; import android.os.Bundle; import android.support.annotation.RequiresApi; ...
Read MoreArithmetic of Number Systems
A number system is a set of symbols used to represent values derived from a common base or radix. In a number, the value of each digit can be determined using digit, position of the digit in the number, and the base of the number system. The base is defined as the total number of digits are available in the number system. This is known as positional number system.Number SystemBaseDigit UsedBinary20, 1Octal80, 1, 2, 3, 4, 5, 6, 7Decimal100, 1, 2, 3, 4, 5, 6, 7, 8, 9Hexadecimal160, 1, 2, 3, 4, 5, 6, 7, 8, 9, A, B, C, D, ...
Read MoreHow to create NSIndexPath for TableView in iOS?
Index path is generally a set of two values representing row and section of a table view. Index path can be created in objective C as well as Swift as both are native language of iOS Development.IndexPathForRow is a class method in iOS. To create a index path we need to be sure about the section and row we need to create. Below are the methods of creating an Indexpath.To create an IndexPath in objective C we can use.NSIndexPath *myIP = [NSIndexPath indexPathForRow: Int inSection:Int] ;ExampleNSIndexPath *myIP = [NSIndexPath indexPathForRow: 5 inSection: 2] ;To create an IndexPath in Swift we ...
Read More