pySQL_API

This is a simple approach to Object relational mapping, that allows you to you focus on objects manipulations and ligcal structures, without the need to write the appropriate queries, insert/update..., for different elements

• Python +3.6 is required, only build-in libraries were used.
• PokemonApp is a pokemon game where I implemented pyORM

Add: In order to insert an object, all you have to do is:

>>> from pyORM import orm
>>> obj_ = yourClass(args....)
# 'orm' will identify the object's attributes to generate the DB schema, and will also create the required table if it doesn't exist.
>>> dbSession = orm(obj_) # This will also create the required table if it doesn't exist
>>> dbSession.add()

Update: In order To save the updates:

Automatic update (using a decorator):

As you can see in classExample.py, all you need to do is to put is @updateAfterEvent on top of the method, once the method returns the updated object (Example: return self or return Obj), the decorator will catch it and apply the updates to the appropriate table in the database

from utils import updateAfterEvent
...
class foo:
  @updateAfterEvent
  def method1(self, args...):
    ...
    return self

  @updateAfterEvent
  def method2(self, obj_2, args ...):
    ...
    return obj_2

• You can put the decorator in a separate file then import it wherever you'll be using it (Ex: utils.py)

Manual update

You can use the function updateObj (defined in utils.py):

from utils import updateObj
obj_.attr += 10
updateObj(obj_)

Or you can do the same manually:

obj_.attr += 10
dbSession = orm(obj_)
updates_ = {k:v[0] for k, v in obj_.__dict__.items() if k[0]!="_"}
# pKey is the name of the primary key
dbSession.update({pKey: getattr(obj_, pKey)[0]}, **updates_)

Get: This module works in two directions, either it project your python's objects to a relational database, or create/reinitiate previously created objects based on the data saved in the DB.

In this case you shouldn't initialize orm with an object like in the previous examples.

dbSession = orm()
#Specifying tablename is the only requirement, then you can send any number of arguments (the logical operator between them is 'AND')
respSQL = dbSession.filterBy.get(tablename="dummy", arg1="...", arg2=1, ...)[0]
# I added [0] because I only wanted the first item from the array, but you can iterate you initiate multiple objects
obj_ = yourClass(*respSQL)

Delete: The same as in Get

dbSession = orm()
#Specifying tablename is the only requirement, then 
dbSession.filterBy.delete(tablename="dummy", arg1="...", arg2=1, ...)[0]

In a nutshell:

All you need to do to implement this module is having the initialized attributes follow this struct:

class dummy:
  # setting __tablename__ is mandatory
  __tablename__ = "dummy"
  def __init__(self, name, args...):
     ...
    # Just replace self.name = name with
   self.name = [name, "VARCHAR(255)", {"PRIMARY KEY": False, "AUTOINCREMENT": False, "FOREIGN KEY {} REFERENCES ...": False}]

• In self.name[2] you can set any number of contrains you wish or none, but you must specify whether it's a primary key.

Let make this more interesting and add the decorator!

from myutils import updateAfterEvent

class dummy:
...
def __init__(self, args...):
   ...
@updateAfterEvent
def method(self, args...):
   ...
   return self #Or return the object you wish to update

Example: (from PokemonApp)

pika = PokemonClass(name="Pikachu", ..., hp=90)
crocodil = PokemonClass(name="Crocordil", ... , hp=90)


dbSession = orm(pika)
if not dbSession.add():
  print("{} Added successfully".format(pika.name[0]))

dbSession = orm(crocodil)
if not dbSession.add():
  print("{} Added successfully".format(crocodil.name[0]))



#Example of an attack
print(pika.hp[0], crocodil.hp[0])
# After the attack 'crocodil' will lose health points and the decorator will save the updated value in the database
crocodil = pika.attack(crocodil)
print(pika.hp[0], crocodil.hp[0])



# Extract pokemons attributes and instantiate pokemon object
dbSession = orm()

pokSQL = dbSession.filterBy.get(tablename="dummy", name="Pikachu")[0]
pika = dummyPokemonClass(*pokSQL)

pokSQL = dbSession.filterBy.get(tablename="dummy", name="Crocordil")[0]
crocodil = dummyPokemonClass(*pokSQL)



print(pika.name[0], crocodil.name[0])

# This time crocodil's hp will be 80 due to the previous attack
print(pika.hp[0], crocodil.hp[0])