Tutorial by Topics

Transactions are protective blocks where SQL statements are only permanent if they can all succeed as one atomic action. The classic example is a transfer between two accounts where you can only have a deposit if the withdrawal succeeded and vice versa. Transactions enforce the integrity of the da...

infix [integer] ops infixl [integer] ops infixr [integer] ops Declaration componentMeaninginfixrthe operator is right-associativeinfixlthe operator is left-associativeinfixthe operator is non-associativeoptional digitbinding precedence of the operator (range 0...9, default 9)op1, ... , opn...

This example uses a Search Cursor from the Data Access (da) module of ArcPy. Do not confuse arcpy.da.SearchCursor syntax with the earlier and slower arcpy.SearchCursor(). The Data Access module (arcpy.da) has only been available since ArcGIS 10.1 for Desktop.

CTFE is a mechanism which allows the compiler to execute functions at compile time. There is no special set of the D language necessary to use this feature - whenever a function just depends on compile time known values the D compiler might decide to interpret it during compilation. You can also ...

class Foo { } // inherits from Object class Bar: Foo { } // Bar is a Foo too Foo f = new Foo(); // instantiate new objects on the heap See the specification, browse a book chapter on classes, inheritance and play interactively.

for (<initializer>; <loop condition>; <loop statement>) { <statements> } while (<condition>) { <statements> } do { <statements> } while (<condition>); foreach (<el>, <collection>) foreach_reverse (<el>, <collection>) ...

What is the config system SilverStripe uses a global config system to store settings for classes and the application. These config variables can be used to define the structure of Models, security settings on Controllers or API keys for third party services. How it works Config values are p...

Firebird (firebird) is an open-source Relational Database Management System (RDBMS). It is open source and free. It is powerful and easily managed. Firebird runs on various systems. For example, Firebird 2.5 runs on Windows (32- and 64-bit), various Linux versions (32- and 64- bit), Solaris (Spar...

<switch> is a conditional processing attribute. It doesn't prevent elements from being referenced by other elements. In our case, <switch> evaluates the systemLanguage value on its direct child elements that matches the user's language. Once is found, the child is rendered and the othe...

This section provides an overview of what varnish is, and why a developer might want to use it. It should also mention any large subjects within varnish, and link out to the related topics. Since the Documentation for varnish is new, you may need to create initial versions of those related topic...

Programs written in C++ need to be compiled before they can be run. There is a large variety of compilers available depending on your operating system. Most operating systems ship without a compiler, and they have to be installed later. Some common compilers choices are: GCC, the GNU Compil...

ImageView (android.widget.ImageView) is a View for displaying and manipulating image resources, such as Drawables and Bitmaps. Some effects, discussed in this topic, can be applied to the image. The image source can be set in XML file (layout folder) or by programatically in Java code. The me...

Over the years, InnoDB has improved to the point where it is almost always better than MyISAM, at least the currently supported versions. Bottom line: Don't use MyISAM, except maybe for tables that are truly temporary. One advantage of MyISAM over InnoDB remains: It is 2x-3x smaller in space r...

Official Documentation: Detecting Common Gestures