Tutorial by Examples: re

create table empl ( name text primary key, boss text null references name on update cascade on delete cascade default null ); insert into empl values ('Paul',null); insert into empl values ('Luke','Paul'); insert into empl values ('Kate'...

The REPLICATE function concatenates a string with itself a specified number of times. Syntax is: REPLICATE ( string-expression , integer ) SELECT REPLICATE ('Hello',4) --returns 'HelloHelloHelloHello'

A metatable defines a set of operations which alter the behaviour of a lua object. A metatable is just an ordinary table, which is used in a special way. local meta = { } -- create a table for use as metatable -- a metatable can change the behaviour of many things -- here we modify the 'tostrin...

There are many more metamethods, some of them are arithmetic (e.g. addition, subtraction, multiplication), there are bitwise operations (and, or, xor, shift), comparison (<, >) and also basic type operations like == and # (equality and length). Lets build a class which supports many of these o...

import javax.swing.JButton; import javax.swing.JFrame; import javax.swing.JLabel; import javax.swing.JPanel; import javax.swing.SwingUtilities; import javax.swing.WindowConstants; /** * A very simple Swing example. */ public class SwingExample { /** * The number of times the ...

You can create a new branch and switch to it using git checkout -b AP-57 After you use git checkout to create a new branch, you will need to set that upstream origin to push to using git push --set-upstream origin AP-57 After that, you can use git push while you are on that branch.

import std.format; void main() { string s = "Name Surname 18"; string name, surname; int age; formattedRead(s, "%s %s %s", &name, &surname, &age); // %s selects a format based on the corresponding argument's type } Official documentatio...

To get template item by template Id. TemplateItem templateItem = Sitecore.Context.Database.GetTemplate(new ID("{11111111-1111-1111-1111-111111111111}"));

Input the name of the template to get the template by using GetTemplate Method. TemplateItem templateItem = Sitecore.Context.Database.GetTemplate("NameOfTheTemplate");

A WM_CREATE message is sent to your window procedure during the window's CreateWindowEx call. The lp argument contains a pointer to a CREATESTRUCT which contains the arguments passed to CreateWindowEx. If an application returns 0 from WM_CREATE, the window is created. If an application returns -1, ...

To get version 5394 use: svn co --revision r5394 https://svn.example.com/svn/MyRepo/MyProject/trunk Or the shorter version: svn co -r 5394 https://svn.example.com/svn/MyRepo/MyProject/trunk Or by using pegged revisions: svn co https://svn.example.com/svn/MyRepo/MyProject/trunk@5394 If al...

pip assists in creating requirements.txt files by providing the freeze option. pip freeze > requirements.txt This will save a list of all packages and their version installed on the system to a file named requirements.txt in the current folder.

pip assists in creating requirements.txt files by providing the freeze option. pip freeze --local > requirements.txt The --local parameter will only output a list of packages and versions that are installed locally to a virtualenv. Global packages will not be listed.

To make artisan migrate a fresh database before running tests, use DatabaseMigrations. Also if you want to avoid middleware like Auth, use WithoutMiddleware. <?php use Illuminate\Foundation\Testing\WithoutMiddleware; use Illuminate\Foundation\Testing\DatabaseMigrations; class ExampleTest ...

The steps of overload resolution are: Find candidate functions via name lookup. Unqualified calls will perform both regular unqualified lookup as well as argument-dependent lookup (if applicable). Filter the set of candidate functions to a set of viable functions. A viable function for whi...

Recursion can be defined as: A method that calls itself until a specific condition is met. An excellent and simple example of recursion is a method that will get the factorial of a given number: public int Factorial(int number) { return number == 0 ? 1 : n * Factorial(number - 1); } ...

In the timeline of any DisplayObject that is attached as a descendant of the display tree, you can utilise the root property. This property points to the main timeline in the case of no custom document class, or the document class if you do define one. Because root is typed DisplayObject, the compi...

A list of recognised color keyword names can be found in the W3C Recommendation for SVG. <svg xmlns="http://www.w3.org/2000/svg" xmlns:xlink="http://www.w3.org/1999/xlink"> <circle r="30" cx="100" cy="100" fill="red" stroke=&qu...

where can serve two purposes in C#: type constraining in a generic argument, and filtering LINQ queries. In a generic class, let's consider public class Cup<T> { // ... } T is called a type parameter. The class definition can impose constraints on the actual types that can be suppl...

To search for a string inside a string, there are several functions: indexOf( searchString ) and lastIndexOf( searchString ) indexOf() will return the index of the first occurrence of searchString in the string. If searchString is not found, then -1 is returned. var string = "Hello, World!&q...