orm.py

from pprint import pprint
import sqlite3

conn = sqlite3.connect( 'babyorm.db' )
c = conn.cursor()

class Model( dict ):
	def __init__(self, **kwargs):
		# c.execute('pragma table_info("{}")'.format(self.__class__.__name__))
		self.columns = self.__columns()

		for key, value in kwargs.items():
			setattr(self, key, value)

	def __setitem__(self, key, value):
		if key in self.columns:
			return super().__setitem__(key, value)
		else:
			return False

	def __setattr__(self, key, value):
		self.__setitem__(key, value)

		return super().__setattr__(key, value)

	@staticmethod
	def __parse_args(obj, on_join=" AND "): # needs better name
		return on_join.join("{} = '{}'".format(name, value) for name, value in obj.items())

	@classmethod
	def __row_to_dict(cls, row): 
		return {column:row[index] for index, column in enumerate( cls.__columns() )}

	@classmethod
	def __columns(cls, force_update=False):
		if force_update or hasattr(cls, 'column'):
			return cls.column

		c.execute('pragma table_info("{}")'.format(cls.__name__))
		cls.columns = tuple(d[1] for d in c)

		return cls.columns

	@classmethod
	def all(cls):
		c.execute( "SELECT * FROM {}".format(cls.__name__) )

		return [cls(**cls.__row_to_dict(row)) for row in c.fetchall()]

	@classmethod
	def get(cls, *args, **kwargs):
		kwargs_ = {'id': args[0]} if args else kwargs
		c.execute("SELECT * FROM {} WHERE {} limit 1".format(
			cls.__name__,
			cls.__parse_args(kwargs_)
		))

		return cls(**cls.__row_to_dict(c.fetchone()))

	@classmethod
	def filter(cls, **kwargs):

		c.execute("SELECT * FROM {} WHERE {} ".format(
			cls.__name__,
			cls.__parse_args(kwargs)
		))

		return [cls(**cls.__row_to_dict(row)) for row in c.fetchall()]

	def save( self ):
		if 'id' in self:
			self.update()
		else:
			self.create()

	def create( self ):
		keys = ','.join( [key for key in self.keys()] )
		values = ','.join( ["'{}'".format(value) for value in self.values()] )

		sql_string = "INSERT INTO {} ({}) VALUES ({})".format(
			self.__class__.__name__,
			keys,
			values
		)
		print(sql_string)
		c.execute(sql_string)

		setattr(self, 'id', c.lastrowid)
		conn.commit()
		return self

	def update( self ):
		c.execute("UPDATE {} SET {} WHERE id={}".format(
			self.__class__.__name__,
			self.__parse_args(self, ', '),
			self['id']
		) )

		conn.commit()

###don't touch the code for these
class Users(Model):
	pass

class Stocks(Model):
	pass

if __name__ == '__main__':
	pass
	# dan = Users(name='dan')
	# dan.save()
	# dan.email = "[email protected]"
	# dan.save()
	# pprint(dan)

	# print( 'all' )
	# pprint( Users.all() )
	# print( 'get' )
	# pprint( Users.get(name="Kenny") )
	# print( 'filter' )
	# pprint( Users.filter(id=dan['id']) )