Tutorial by Examples: o

SELECT COALESCE(NULL, NULL, 'TechOnTheNet.com', NULL, 'CheckYourMath.com'); Result: 'TechOnTheNet.com' SELECT COALESCE(NULL, 'TechOnTheNet.com', 'CheckYourMath.com'); Result: 'TechOnTheNet.com' SELECT COALESCE(NULL, NULL, 1, 2, 3, NULL, 4); Result: 1

An object can only be deallocated by delete if it was allocated by new and is not an array. If the argument to delete was not returned by new or is an array, the behavior is undefined. An object can only be deallocated by delete[] if it was allocated by new and is an array. If the argument to delet...

USE msdb Go SELECT dbo.sysjobs.Name AS 'Job Name', 'Job Enabled' = CASE dbo.sysjobs.Enabled WHEN 1 THEN 'Yes' WHEN 0 THEN 'No' END, 'Frequency' = CASE dbo.sysschedules.freq_type WHEN 1 THEN 'Once' WHEN 4 THEN 'Daily' ...

WITHOUT_ARRAY_WRAPPER option in FOR JSON clause will remove array brackets from the JSON output. This is useful if you are returning single row in the query. Note: this option will produce invalid JSON output if more than one row is returned. Input table data (People table) IdNameAge1John232J...

OPENJSON function parses JSON text and returns multiple outputs. Values that should be returned are specified using the paths defined in the WITH clause. If a path is not specified for some column, the column name is used as a path. This function casts returned values to the SQL types defined in the...

Structures and arrays of structures can be initialized by a series of values enclosed in braces, one value per member of the structure. struct Date { int year; int month; int day; }; struct Date us_independence_day = { 1776, 7, 4 }; struct Date uk_battles[] = { { 1066, ...

A basic function is defined and executed like this: function hello($name) { print "Hello $name"; } hello("Alice");

Functions can have optional parameters, for example: function hello($name, $style = 'Formal') { switch ($style) { case 'Formal': print "Good Day $name"; break; case 'Informal': print "Hi $name"; break; ...

The standard requires that long double provides at least as much precision as double, which provides at least as much precision as float; and that a long double can represent any value that a double can represent, while a double can represent any value that a float can represent. The details of the ...

Lists can also be assigned to hash variables. When creating a list that will be assigned to a hash variable, it is recommended to use the fat comma => between keys and values to show their relationship: my %hash = ( foo => 42, bar => 43, baz => 44 ); The => is really only a specia...

As to pass list into a subroutine, you specify the subroutine's name and then supply the list to it: test_subroutine( 'item1', 'item2' ); test_subroutine 'item1', 'item2'; # same Internally Perl makes aliases to those arguments and put them into the array @_ which is available within the s...

If you like to organize your project by keeping source files in different subdirectories, you should know that during a build qmake will not preserve this directory structure and it will keep all the ".o" files in a single build directory. This can be a problem if you had conflicting file ...

public function actionFormSubmission() { $security = new Security(); $string = Yii::$app->request->post('string'); $stringHash = ''; if (!is_null($string)) { $stringHash = $security->generatePasswordHash($string); } return $this->render('form-submi...

When a migration is run, Django stores the name of the migration in a django_migrations table. Create and Fake initial migrations for existing schema If your app already has models and database tables, and doesn’t have migrations. First create initial migrations for you app. python manage.py mak...

A simple Hello, World program without error checking: #include <unistd.h> /* For write() and STDOUT_FILENO */ #include <stdlib.h> /* For EXIT_SUCCESS and EXIT_FAILURE */ int main(void) { char hello[] = "Hello, World\n"; /* Attempt to write `hell...

The following example creates a unique index on the JobCandidateID column of the HumanResources.JobCandidate table of the AdventureWorks2012 sample database. The example then creates a default full-text catalog, ft. Finally, the example creates a full-text index on the Resume column, using the ft ca...

USE AdventureWorks2012; GO CREATE FULLTEXT CATALOG production_catalog; GO CREATE FULLTEXT INDEX ON Production.ProductReview ( ReviewerName Language 1033, EmailAddress Language 1033, Comments Language 1033 ) KEY INDEX PK_ProductR...

USE AdventureWorks2012; GO CREATE FULLTEXT INDEX ON Production.Document ( Title Language 1033, DocumentSummary Language 1033, Document TYPE COLUMN FileExtension Language 1033 ) KEY INDEX PK_Document_DocumentID ...

Postmodern is a library to interface the relational database PostgreSQL. It offers several levels of access to PostgreSQL, from the execution of SQL queries represented as strings, or as lists, to an object-relational mapping. The database used in the following examples can be created with these SQ...

This example shows you a minimal way to create a Hello World page in Django. This will help you realize that the django-admin startproject example command basically creates a bunch of folders and files and that you don't necessarily need that structure to run your project. Create a file called ...