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DataBridge

DataBridge is a lightweight ORM built using Ruby.

Running the included Example

  1. git clone https://github.com/williamlemus/DataBridge.git
  2. cd DataBridge
  3. cat teams.sql | sqlite3 teams.db
  4. pry
  5. load 'lib/demo_tables.rb'
  6. Use pry to test out the various commands on the Team, City and/or Player models.

Key Features

  • SQLRecord#save will automatically decide to create a new row or update depending on whether the id exists in the database.
  • First and last records can be retrieved using first and last.
  • Associations can be used in place of mapping relationships on the database, leveraging the power of method chaining in Ruby.

Example Usage

In order to use DataBridge, a model class should be created as show(using the example contained in lib):

class Team < SQLRecord
  self.finalize!
end

Calling finalize will ensure that attribute accessors are created for each of the columns of the database table. The class should be in the singular of the table name(for example, a teams table will have a Team model class). The methods available are listed below.

Available methods

The follow methods can be used on the SQLRecord:

  • save
    • This will save the Model object to the database, or update it if it already exists, so it can be used in place of insert and update.
  • update
    • This will update the row into the database
  • insert
    • This will insert the row into the database
  • find(id)
    • A class method that is given an id, will return the row as a Model instance.
  • all
    • A class method that will return all the records as an array of Model class objects.
  • first
    • A class method that will return the first result in the table.
  • last
    • A class method that will return the first result in the table.

Also, the following associations can be created:

  • belongs_to

    • Creates a one-to-one relationship between models. In the example database, a team belongs to a city. calling the city method will return a city model object of the city the team belongs to.

  • has_many

    • Creates a one-to-many relationship between models. In the example database, a city has many teams. Calling the teams method on a city will return an array of all the teams that are in the city.

  • has_one_through

    • creates a one-to-one relationship going through a belongs to association. For example, a player belongs to a team. Through the team, the player also belongs to a city. To create a city method on a player, we create a has_one_through relationship, where the through parameter is the team relationship, and the source would be city.
    class Player < SQLRecord
  belongs_to :team
  has_one_through :city, :team, :city
  # ...
  self.finalize!
end