CSC/ECE 517 Fall 2012/ch1 1w10 pk

1w10: Language extensions (not patterns or packages) for ORM.

Introduction

Rails provides support for Object-Relational Mapping called Active Record. The ActiveRecord layer implements a Rails application model. It allows developers to easily map data to rows and columns, manage table relationships, and implement create, read, update, and delete operation. Other ORM extensions exist.

History

There are many design patterns and software tools for referencing relational dbs from o-o languages. ActiveRecord, however, is a new approach, integrating support into the Rails framework itself. Do other languages have support that is as tightly integrated as ActiveRecord? Compare the ease of programming with language-level support to the ease of programming with external tools. Improve the existing work.

Section headings

Headings organize your writing into sections. The wiki software can automatically generate a table of contents from them. Start with 2 'equals' ("==") characters.

Subsection

Using more 'equals' characters creates a subsection.

A smaller subsection

Don't skip levels, like from two ("==") to four ("====") 'equals' characters.

A defined term

A semicolon at the

start of a line is a way of making a definition where the word being defined appears in bold. The definition itself follows the colon and is not rendered bold by default. It is not a heading and does not appear in the table of contents.

Lists

• Unordered lists are easy to do:
  • Start every line with a star.
    • More stars indicate a deeper level.

    Previous item continues.

  • A new line
• in a list

marks the end of the list.

• Of course you can start again.

1. Numbered lists are:
   1. Very organized
   2. Easy to follow

   Previous item continues

A new line marks the end of the list.

1. New numbering starts with 1.

Format

Text formatting

Description	What you type	What it looks like
Italics, bold, Template:Smallcaps.	To ''italicize text'', just put 2 apostrophes on each side. 3 apostrophes will '''bold the text''' 5 apostrophes for '''''bold italics''''' For text as {{Smallcaps|small caps}}, that uses a [[Help:Template|template]].	To italicize text, just put 2 apostrophes on each side. 3 apostrophes will bold the text 5 apostrophes for bold italics For text as Template:Smallcaps, that uses a template.
Small chunks of source code within a line of normal text. Code is displayed in a monospace font.	function <code>int m2()</code> is nice	function int m2() is nice
Syntax highlighting for source code. Computer code has colored text and more stringent formatting. For example, to define a function: int m2(), with highlights.	<syntaxhighlight lang="cpp"> #include <iostream> int m2 (int ax, char *p_ax) { std::cout <<"Hello World!"; return 0; }</syntaxhighlight>	#include <iostream> int m2 (int ax, char *p_ax) { std::cout <<"Hello World!"; return 0; }
Small text.	Use <small>small text</small> if needed. A span tag can set text font-size as being <span style="font-size:87%">87% of prior size</span>, to match an image caption.	Use small text if needed. A span tag can set text font-size as being 87% of prior size, to match an image caption.
Big text.	Better not use <big>big text</big>, unless <small> it's <big>within</big> small</small> text.	Better not use big text, unless it's within small text.
You can include a non-breaking space (sometimes called non-printing character) where you require two words to always appear together on the same line, such as Mr. Smith or 400 km/h, using &nbsp; in place of a regular space between the two "words" that need to behave as a single word (never be separated on different lines).	Mr.&nbsp;Smith or 400&nbsp;km/h.	Mr. Smith or 400 km/h.
Extra spacing within text can best be achieved using the pad template.	Mary {{pad|4em}} had a little lamb.	Mary       had a little lamb.
Typewriter font. (Also works beyond the end of a paragraph.)	<tt>arrow &rarr;</tt> <tt>''italics'', '''bold'''</tt> <tt><nowiki>[[link]] New paragraph </tt>started here.	arrow → italics, bold link New paragraph started here.

Link to another wiki article

• Internally, the first letter of the target page is automatically capitalized and spaces are represented as underscores (typing an underscore in the link has the same effect as typing a space, but is not recommended).
• Thus the link hereafter is to the Web address en.wikipedia.org/wiki/Public_transport, which is the Wikipedia article with the name "Public transport". See also Canonicalization.
• A red link is a page that doesn't exist yet; it can be created by clicking on the link.
• A link to its own page will appear only as bold text.

What you type	What it looks like
London has [[public transport]].	London has public transport.
Link to this own article: "[[Help:Wiki markup]]" will appear only as bold text.	Link to this own article: "Help:Wiki markup" will appear only as bold text.