The next phase or step would be to create a database for the application to use. Make sure the MySql engine is running and in the command window type “mysql -u root -p” and press enter and another enter for the password when prompted for there has not been any defined password yet. You are now logged into the engine as the root user and proceed to create the database by entering the following command “create database filename_development”. Also type in “grant all on filename_development.* to ‘ODBC’@'localhost’ this tells windows to grant access to a user named ODBC so you avoid an error when you try to access the said database from the command prompt. We next tackle the creation of tables that would allow the database to store the information we send it.

The database has been initialized, so now we get down to business of defining the fields in that database and include a field that we would call a foreign key which allows the establishment of the one to many relationship between the tables. This part of the process requires quite a bit of background of database creation, manipulation and handling. It also requires knowledge regarding the workings of data types. So assuming you do not have much knowledge in such areas do some more reading to give you a better understanding of what how and why they are there. The ROR developers might say that it is very easy to do and use ROR but without the background on logic formulation, data types and manipulation as well as database handling the rest of the posts which would tackle ever hardening topics and operations would be very difficult to make sense of.

Don’t get me wrong, we just want to make life easier for you and not have you not understanding anything at all.

There are quite a number of directories locate in the apps folder we have just created so to de-mystify them here are some explanations which hopefully would help you out. The directory “app/controllers” is where Rails searches for the controller classes which controls the web request from the user. The next one is the, “app/views” folder which houses the templates to which the data from the app is converted to HTML and then returned to the user’s browser. The next folder houses the “apps/models” subdirectory which contains the data classes that wraps the data stored within the application’s database (this is the messiest part of the framework in other frameworks). Then last of the vital sub-directories is the “app/helpers” which hold the helper classes of data that assists the view, model and controller classes keeping them small, organized and focused on the task it is supposed to do in the first place.

Top find out what each key in the hash is associated with :

salad['green salad'] => “lettuce and sweet basil”

As with arrays, there are a lot of useful methods in creating them.

salad.empty? (to check if the hash is empty)
salad.size (to check for the number of elements in the hash)
salad.keys (to get all the keys in the hash to create an array)
salad.values (to get the keys in the form of an array but not necessarily in the order they’ve been entered in the hash)

All the above operations are built-in methods that are used for such purposes.

Hashes are simply arrays that link one object to another object (think of it as an association of sorts), say like Spagthetti_sauce which is part of the complete menu, referring to the hash Spaghetti_sauce gives you the ingredients. Same as with arrays, they are created with the “.new” method resulting in an empty hash.

salad = Hash.new

Using curly braces, you get to assign the hash its elements like the example shown below:

salad = {
green salad => ‘lettuce and sweet basil’
coleslaw => ’shredded lettuce, garlic and onions, carrots’
garden fresh => ‘cherry tomatoes, lettuce, iceberg, iceberg lettuce, mayonnaise, olive oil, lemons
}

The caret “^” and the “&” operators are used for matching the beginning of a string, and also for the end of a string shown below:

matching =/[a-e]$/

The script would look for similar letters between “a” and “e” respectively including the end of the string. To search for a letter inside a string:

[A-Z] all uppercase letters
[a-z] all lowercase letters
[0-9] all digits(numbers)

To restrict the range, say to look for only the letters between “a” and “e”, you write it as [a-e] combined with the caret operator shown below:

[^A-Z] all other characters except uppercase letters
[^a-z] all other characters except lowercase letters
[^A-Za-z] no letters, whether upper or lower case

Ruby expressions would be shocking for the uninitiated or those who are shifting form other programming languages. If you have experience with Perl or Python, then you’re in luck for they won’t send you packing up and running in fear. The term “regular expression” is used to have a program check if it looks like something else in terms of similar characters or spacing, length or a myriad of other things that you may think of. The table form Ruby.org summarizes all the Ruby expressions and elements. Regular expressions are used for matching certain patterns such that if you’d want to check for a digit you use the \d expression or to match a space character, you use the \s expression to match a space character.

Image Source: www.web2.socialcomputingmagazine.com

Ruby on Rails is great for acquiring ideas prototyped super quick. These tips will slow down growth and make apps less portable, but definitely progress the speed your system
Ruby on rails coding style:
• Try to evade the over indulgence use of helpers since it adds overhead.
• You may think about using memcached to cache your model and library computation results.
• Use a custom configuration file for passwords and API keys instead of keeping them in your Subversion repository. Use YAML and mirror the style of database.yml.
• Use constants when desired. Instead of repeating strings like the address of your customer service reply email, set it once in a constant (in environment.rb or the appropriate environment file) and use that throughout your application.
• Keep time in UTC. A no brainer, and easy to do.
• Don’t loop through ActiveRecord models inside other models. Use keen loading if you need to exertion with multiple associated models. Better yet, write a custom SQL query and let the database do the work for you.

More on text editors that are used with RoR and we not discuss VIM or Vi Improved. Vim like Emacs is quite efficient and easy to use with RoR provided it is set-up properly. The nice about Vim is that it has the nifty way of highlighting syntax in ruby making it easy to trace and debug. It features advanced features such as having a selective command and insert mode with the first being the default mode upon startup. It is not a word processor so fonts and other word processor features are not to be expected.

TextPad
One of the quickest and easiest to use as a text editor for making RoR programs with straightforward interface and features mostly adept to windows users. Though considered a text editor it is capable of syntax highlighting, search , spell check and macro recording which makes it a choice of many developers.

ArachnoRuby
Is deployable on both windows based and Unix based systems and is considered to be the native editor of RoR. It was not too user friendly so it quickly lost favor of many developers who turned to the other specified editors for programming code.

Assuming you have even just a little background in programming with any language there are four basic programs and extensions that you need but are provided by the quick installers you’ve just downloaded to your hard drive. You have The Ruby programming language program files, the Rails part of the programming extension/platform, MySql or your database query handling system and the Apache which is a web server that you use to emulate your application’s execution on the web. Granting you have these set up properly and tested (instructions for which are included in the installer package). You can now start building your first application with RoR.