Data Structure
Networking
RDBMS
Operating System
Java
MS Excel
iOS
HTML
CSS
Android
Python
C Programming
C++
C#
MongoDB
MySQL
Javascript
PHP
Economics & Finance
Yes, it is possible to enforce data checking in MySQL using regular expression. First, you need to create a table. After that you need to create a trigger before insert in table. Here, we will be checking the Phone Number format.The query to create a table is as followsmysql> create table enforceDataUsingRegularExpression - > ( - > yourPhoneNumber varchar(60) - > ); Query OK, 0 rows affected (0.59 sec)The query to create a trigger is as followsmysql> DELIMITER // mysql> CREATE TRIGGER enforce_phone_check BEFORE INSERT ON enforceDataUsingRegularExpression - ... Read More
The mapToDouble() method returns a DoubleStream consisting of the results of applying the given function to the elements of this stream.The syntax is as follows:DoubleStream mapToDouble(LongToDoubleFunction mapper)The parameter mapper is a stateless function to apply to each element.To use the LongStream class in Java, import the following package:import java.util.stream.LongStream;The following is an example to implement LongStream mapToDouble() method in JavaExampleimport java.util.stream.LongStream; import java.util.stream.DoubleStream; public class Demo { public static void main(String[] args) { LongStream longStream = LongStream.of(5000L, 12000L, 15000L, 20000L, 25000L); DoubleStream s = longStream.mapToDouble(a → (double)a); System.out.println("Elements of DoubleStream..."); ... Read More
To resize an image in iOS using swift we’ll make use of frame.Let’s see this with help of an example.Create an empty project and add an empty Image view.Create its outlet.Add an image to your project and assign the image to image view.Initially when we run the application, it looks something like this.Now, let’s add code to resize the image.override func viewWillLayoutSubviews() { let frame = CGRect(x: 10, y: 10, width: self.view.frame.width - 20, height: 300) self.imgView.frame = frame }We will run this code in our viewWillLayoutSubviews method. This is how it looks on the device when we ... Read More
Weakly or Strongly Connected for a given a directed graph can be find out using DFS. This is a C++ program of this problem.Functions usedBegin Function fillorder() = fill stack with all the vertices. a) Mark the current node as visited and print it b) Recur for all the vertices adjacent to this vertex c) All vertices reachable from v are processed by now, push v to Stack End Begin Function DFS() : a) Mark the current node as visited and print it b) Recur for all the vertices adjacent to this vertex ... Read More
To hide a keyboard on screen we need to make use of some internal functions that are predefined in the iOS SDK. The keyboard appears on screen when we are typing in a text Field or textView. We need to make use of internal function according to the text field.For example if the current text field is tfOne, we can hide the text field using the code below:tfOne.resignFirstResponder()This code will hide the keyboard when ever called, we may call this on an action for a button or for gesture recognizer.This method is good for limited textFields, but we need to ... Read More
You need to use tinyint(1) unsigned NULL to store the value 0, 1 and null values. The syntax is as follows −yourColumnName TINYINT(1) UNSIGNED NULL;To understand the above syntax, let us create a table. The query to create a table is as follows −mysql> create table StoreValue0and1orNULLDemo -> ( -> isDigit TINYINT(1) UNSIGNED NULL -> ); Query OK, 0 rows affected (0.63 sec)Now you can insert records 0, 1, and NULL in the table using insert command. The query is as follows −mysql> insert into StoreValue0and1orNULLDemo values(0); Query OK, 1 row ... Read More
JDBC API is available in two packages java.sql, core API and javax.sql JDBC optional packages. Following are the important classes and interfaces of JDBC.Class/interfaceDescriptionDriverManagerThis class manages the JDBC drivers. You need to register your drivers to this.It provides methods such as registerDriver() and getConnection().DriverThis interface is the Base interface for every driver class i.e. If you want to create a JDBC Driver of your own you need to implement this interface. If you load a Driver class (implementation of this interface), it will create an instance of itself and register with the driver manager.StatementThis interface represents a static SQL statement. ... Read More
This example demonstrate about How to get default phone IMEI 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 a text view to show phone IMEI.Step 3 − Add the following code to java/MainActivity.xmlpackage com.example.myapplication; import android.Manifest; import android.content.Context; import android.content.pm.PackageManager; import android.os.Build; import android.os.Bundle; import android.support.annotation.NonNull; import android.support.annotation.RequiresApi; import android.support.v4.app.ActivityCompat; import android.support.v7.app.AppCompatActivity; import android.telephony.TelephonyManager; import android.widget.TextView; import static android.Manifest.permission.READ_PHONE_NUMBERS; import static ... Read More
You can use SET command, but SET OPTIOn deprecated. Therefore, use SET SQL_SELECT_LIMIT.The syntax is as follows −SET SQL_SELECT_LIMIT=yourIntegerValue;To understand the above syntax, let us create a table. The query to create a table is as follows −mysql> create table MySQLSelectDemo -> ( -> Id int NOT NULL AUTO_INCREMENT PRIMARY KEY -> ); Query OK, 0 rows affected (0.99 sec)Insert some records in the table using insert command. The query is as follows −mysql> INSERT INTO MySQLSelectDemo VALUES(), (), (), (), (), (), (), (), (), (), (), (), (), (), (), (), (), (), (), (), ... Read More
ReferencesWhen a variable is declared as reference, it becomes an alternative name for an existing variable.SyntaxType &newname = existing name;InitializatioType &pointer; pointer = variable name;PointersPointers are used to store the address of variable.SyntaxType *pointer;InitializationType *pointer; pointer = variable name;The main differences between references and pointers are -References are used to refer an existing variable in another name whereas pointers are used to store address of variable.References cannot have a null value assigned but pointer can.A reference variable can be referenced by pass by value whereas a pointer can be referenced but pass by reference.A reference must be initialized on declaration ... Read More