LazyRecord

LazyRecord is an object-relational mapper inspired by Active Record. It connects classes to relational database tables, establishing the basic framework to object oriented programing to work as an application.

How to use:

Clone this repo
Run bundle install in the root directory to install the gems
Run bundle exec pry in the root directory to go in pry
Explore the ORM!

Methods Available

::all
::table_name
::find(id)
::new()
#save
#update
#attributes
#attributes_values

Sample Database Scheme

Humans table

column name	data type	details
id	integer	not null, primary key
fname	string	not null
lname	string	not null

Dogs table

column name	data type	details
id	integer	not null, primary key
name	string	not null
owner_id	integer	not null, unique, indexed

Toys table

column name	data type	details
id	integer	not null, primary key
name	string	not null
dog_id	integer	not null, unique, indexed

Inspiration

Dog.all # returns an array of dogs
human1 = Human.find(1) # returns #<Human:0x00007fd5e72e0850 @attributes={:id=>1, :fname=>"Lily", :lname=>"Andrews"}>
human1.dogs # returns an array of dogs belonging to the human

bone_toy = Toy.where(name: 'Bone').first # returns #<Toy:0x00007fd5e8af99a0 
                                         #      @attributes={:id=>1, :name=>"Bone", :dog_id=>4}>
bone_toy.dog # returns #<Dog:0x00007fd5e8a9c278 @attributes={:id=>4, :name=>"Charlie", :owner_id=>3}>

brownie = Dog.new(name: 'Brownie', owner_id: 2) # returns => #<Dog:0x00007fd5e7839ae0 
                                                #      @attributes={:name=>"Brownie", :owner_id=>2}>
brownie.save # saves the dog, returns the dog id (7)
Dog.all.last # returns #<Dog:0x00007fd5e8a64ff8 @attributes={:id=>7, :name=>"Brownie", :owner_id=>2}>

thomas = Human.where(fname: 'Thomas').first # returns #<Human:0x00007fd5e7318250 
                                            #      @attributes={:id=>2, :fname=>"Thomas", :lname=>"Smith"}>
thomas.Name = 'not Thomas' # returns 'not Thomas'
thomas.update # returns 0
Human.find(2) # returns #<Human:0x00007fd5e7318250 
              #      @attributes={:id=>2, :fname=>"not Thomas", :lname=>"Smith"}>

Next Steps

Create the possibility to have has_many_through relations
Create the possibility to prevent n+1 queries
Create the possibility to select specific fields instead of selecting every field

mafeg95/LazyRecord