ahl2e / lazy_record

lazy_record

Lazy Record is lightweight Object Relational Mapping software inspired by Rails' Active Record

• Metaprogramming allows users to easily create connections between data tables.
• Complicted SQL queries are automated for the user

Demo

Databases

Cats

id	ownerId	name	color	gender
1	1	Oscar	black	male
2	1	Misty	white	female
3	3	Sparkles	orange	male
4	2	Patches	brown	female
5	4	Tigger	orange	male

People

id	name	gender
1	Tim	male
2	Mary	female
3	Molly	female
4	John	male

SQLObject

class Cat < SQLObject
end 

class Person < SQLObject
end

::all

::all allows you to find all SQLObjects from a table in the database.

people = Person.all

Result

{
  id: 1,
  name: 'Tim',
  gender: 'female'
},
{
  id: 2,
  name: 'Mary',
  gender: 'female'
},
{
  id: 3,
  name: 'Molly',
  gender: 'female'
},
{
  id: 4,
  name: 'John',
  gender: 'male'
}

::find

::find allows you to find a single SQLObject from the database by its id.

tim = Person.find(1)

Result

{
  id: 1,
  name: 'Tim',
  gender: 'male'
}

::find_by

::find_by allows you to find a single SQLObject from the database by any attribute and value passed in as a key-value pair.

time = Person.find_by(id: 1)

Result

{
  id: 1,
  name: 'Tim',
  gender: 'male'
}

#insert

#insert allows you to insert a newly created SQLObject into the database, and automatically assigns it a valid id.

mike = Person.new(name: 'Mike', gender: 'male')
mike.insert

New Database

id	name	gender
1	Tim	male
2	Mary	female
3	Molly	female
4	John	male
5	Mike	male

#update

#update allows you to update an existing SQLObject to the database.

tim = Person.find(1)
tim.name = 'Bob'
tim.update

New Database

id	name	gender
1	Bob	male
2	Mary	female
3	Molly	female
4	John	male
5	Mike	male

#save

#save allows you to insert a new SQLObject or update an existing SQLObject if it already exists.

bob = Person.find(1)
bob.name = 'Tim'
jenn = Person.new(name: 'Jenn', gender: 'female')

bob.save
jenn.save

New Database

id	name	gender
1	Tim	male
2	Mary	female
3	Molly	female
4	John	male
5	Mike	male
6	Jenn	female

::where

::where allows you to find all SQLObjects from the database by any attribute and value passed in as a key-value pair.

people = Person.where(gender: male)

Result

{
  id: 1,
  name: 'Tim',
  gender: 'male'
},
{
  id: 4,
  name: 'John',
  gender: 'male'
},
{
  id: 5,
  name: 'Mike',
  gender: 'male'
}

::has_many

::has_many allows you to define a 'has-many' relationship between 2 SQLObjects.

class Person < SQLObject
  has_many :cats,
    foreign_key: :ownerId,
    primary_key: :id,
    class_name: "Cat"
end 

tim = Person.find(1)
tim.cats

Result

{
  id: 1,
  ownerId: 1,
  name: "Oscar",
  color: "black",
  gender: "male"
},
{
  id: 2,
  ownderId: 1,
  name: "Misty",
  color: "white",
  gender: "female"
}

::belongs_to

::belongs_to allows you to define a 'has-many' relationship between 2 SQLObjects.

class Cat < SQLObject
  belongs_to :owner,
    foreign_key: :ownerId,
    primary_key: :id,
    class_name: "Person"
end

oscar = Cat.find(1);
oscar.owner

Result

{
  id: 1,
  name: "Oscar",
  gender: "male"
}