Tutorial by Examples: ed

This section describes some basic DDL (="Data Definition Language") commands to create a database, a table within a database, a view and finally a stored procedure. Create Database The following SQL command creates a new database Northwind on the current server, using pathC:\Program Fi...

You can list all files ignored by git in current directory with command: git status --ignored So if we have repository structure like this: .git .gitignore ./example_1 ./dir/example_2 ./example_2 ...and .gitignore file containing: example_2 ...than result of the command will be: $ g...

a='I am a simple string with digits 1234' pat='(.*) ([0-9]+)' [[ "$a" =~ $pat ]] echo "${BASH_REMATCH[0]}" echo "${BASH_REMATCH[1]}" echo "${BASH_REMATCH[2]}" Output: I am a simple string with digits 1234 I am a simple string with digits 1234

Class Car ... ' Parameterless Constructor Public Sub Class_Initialize() distances_ = Array(0) End Sub ' Default initialization method that can be invoked without ' explicitly using the method name. Public Default Function Init(wheels) wheels_ = ...

This example renders justified text. It adds extra functionality to the CanvasRenderingContext2D by extending its prototype or as a global object justifiedText (optional see Note A). Example rendering. Code to render this image is in the usage examples at the bottom. The Example The functi...

Renders text as justified paragraphs. REQUIRES the example Justified text Example render Top paragraph has setting.compact = true and bottom false and line spacing is 1.2 rather than the default 1.5. Rendered by code usage example bottom of this example. Example code // Requires justified...

ps -e | less ps -e shows all the processes, its output is connected to the input of more via |, less paginates the results.

foo() { while [[ "$#" -gt 0 ]] do case $1 in -f|--follow) local FOLLOW="following" ;; -t|--tail) local TAIL="tail=$2" ;; esac shift done echo "FOLLOW: $FOLLOW" echo "TAIL: $...

This very simple snippet of XQuery can be executed in QueryConsole using the built-in "Documents" database as a sandbox. Each piece of the snippet has a comment to explain what the following line of code means. xquery version "1.0-ml"; (: Let's first insert a simple document to...

If we know the desired URI of the document we are looking for: fn:doc("/stuff/mysimpledocument.xml") Returns the full document from the database, using the URI to locate it. Since this is XQuery, we can use XPath to find the document when we know about the structure, but not the URI: ...

We will now add some additional XML nodes to the "my-document" element and update the document. The snippet again contains comments to explain what is happening. xquery version "1.0-ml"; (: We are preserving the same URI as we used originally :) let $uri := "/stuff/mysimp...

Traditionally in Prolog, "functions" (with one output and bound inputs) were written as regular predicates: mangle(X,Y) :- Y is (X*5)+2. This can create the difficulty that if a function-style predicate is called multiple times, it is necessary to "daisy chain" temporary vari...

int width = 256; //in pixels int height = 256; //in pixels BufferedImage image = new BufferedImage(width, height, BufferedImage.TYPE_4BYTE_ABGR); //BufferedImage.TYPE_4BYTE_ABGR - store RGB color and visibility (alpha), see javadoc for more info Graphics g = image.createGraphics(); //draw w...

BufferedImage cat = ImageIO.read(new File("cat.jpg")); //read existing file //modify it Graphics g = cat.createGraphics(); g.setColor(Color.RED); g.drawString("Cat", 10, 10); g.dispose(); //now create a new image BufferedImage cats = new BufferedImage(256, 256, Buffere...

BufferedImage image = new BufferedImage(256, 256, BufferedImage.TYPE_INT_ARGB); //you don't have to use the Graphics object, you can read and set pixel color individually for (int i = 0; i < 256; i++) { for (int j = 0; j < 256; j++) { int alpha = 255; //don't forget this, or ...

First Initialize FirebaseDatabase: FirebaseDatabase database = FirebaseDatabase.getInstance(); Write to your database: // Write a message to the database FirebaseDatabase database = FirebaseDatabase.getInstance(); DatabaseReference myRef = database.getReference("message"); myRef....

You can retrieve the data stored at the located referenced by the pointer variable, using the ToString() method. The following example demonstrates this: using System; namespace UnsafeCodeApplication { class Program { public static void Main() { unsafe { ...

Implementation of IDatabaseInitializer that is used in EntityFramework by default. As the name implies, it creates the database if none exists. However when you change the model, it throws an exception. Usage: public class MyContext : DbContext { public MyContext() { Database.SetIni...

This implementation of IDatabaseInitializer drops and recreates the database if the model changes automatically. Usage: public class MyContext : DbContext { public MyContext() { Database.SetInitializer(new DropCreateDatabaseIfModelChanges<MyContext>()); } }

This implementation of IDatabaseInitializer drops and recreates the database everytime your context is used in applications app domain. Beware of the data loss due to the fact, that the database is recreated. Usage: public class MyContext : DbContext { public MyContext() { Database.S...