model and table relationship

rubyonrails-talk
1

According to 'Agile web development with rails' "... a model is automatically mapped to a database table whose name is the plural form of the model's class". Sure enough, when I created migrations for 'Tc_project', 'Tc_employee' and 'Tc_period' the migration files issue a 'create table' with the table names pluralized. However, when I issue "Rails generate scaffold Tc_data..." the create table statement in the migration DID NOT pluralize 'tc_data' to 'tc_datas'!

Does anyone know if this will create a 'convention' problem between model and table references for the table 'Tc_data'? Unless I hear otherwise I will assume Rails knows what it is doing and run the migration as-is and proceed as if nothing is out of the ordinary. If Rails chokes on this I will post a reply to my own question.

Thanks in advance for any help. Fred

2

Rails is smart enough to know that the plural of some words are irregular (examples: category, person) and that some words are “uncountable” (examples: money, information).

Since “data” is already the plural form of “datum” I think Rails knows not to make it “datas”.

You should be good to go.

3

As Tim has pointed out, this should be datum for the singular and data for the plural. I would also point out that you will make life easier for yourself if you stick to the Rails conventions for capitalisation and underscores. In this case the class would be something like TcDatum and the table tc_data (or something completely different if you do not like datum). Similarly I would change the names of the other classes you mention.

Colin Colin

4

"you will make life easier for yourself if you stick to the Rails conventions for capitalisation and underscores."

Actually I was trying to do that. My boss told me (he is also a newbie) that table names start with a capital letter, though I cannot find documentation to that effect. If you can point me to any references to naming conventions I would appreciate it, thanks.

I start each table with "tc_" because I am coming from Drupal where all tables of all modules are in one database and this is necessary to prevent name conflicts.

All help is greatly appreciated. -Fred

5

Hi All, I want to create an application in order to convert web page in to pdf. like the below I/p => http://www.test.com o/p => pdf file has the content of http://www.test.com page. Is their any plugins available for this option.

Thanks in avance

Thanks & Regards, Loganathan

6

"you will make life easier for yourself if you stick to the Rails

conventions for capitalisation and underscores."

Actually I was trying to do that. My boss told me (he is also a

newbie) that table names start with a capital letter, though I cannot

find documentation to that effect.

If you can point me to any references to naming conventions I would

appreciate it, thanks.

Table names are all lowercase by convention (and plural). Model names are singular, capitalized CamelCase. In fact, it is a ruby-wide convention that class names are capitalized CamelCase (not just rails).

I start each table with “tc_” because I am coming from Drupal where

all tables of all modules are in one database and this is necessary to

prevent name conflicts.

As for having a prefix, you might be interested in the #table_name_prefix property:

This would allow you to have tables named:

tc_projects

tc_employees

tc_periods

tc_datum

And model classes respectively:

class Project < ActiveRecord::Base

table_name_prefix = “tc_”

end

…

class Datum < ActiveRecord::Base

table_name_prefix = “tc_”

end

In order to then DRY up your code a bit, you might be able to use an abstract base class:

class TcPrefix < ActiveRecord::Base

table_name_prefix = “tc_”

abstract_class = true

end

class Project < TcPrefix

end

…

class Datum < TcPrefix

end

I haven’t tested this to see if this variation works correctly. I’d give a try though.

7

tc_datum

Woops, table name would be tc_data while the class would be Data (or TcData if you don’t use table_name_prefix). My bad.

8

Oh my gosh. I need some sleep and to actually proof-read what I type before I click “Send”.

Table name: tc_data Model name: Datum or TcDatum

(crawling back into my hole…)