input: Write a function to load a JSON fixture file, extract properties, create Property objects from the extracted properties, and save them to a database. The function should return the number of properties saved. The JSON fixture file should be specified using command line arguments.
  assert main('/path/to/fixture/folder')==5
  assert main('/path/to/fixture/folder')==0
  assert main('/path/to/fixture/folder')==10
output: 
  def main(fixture_path):
      import json
      from pathlib import Path
      from sqlalchemy import create_engine, Column, Integer, String
      from sqlalchemy.ext.declarative import declarative_base
      from sqlalchemy.orm import sessionmaker
  
      Base = declarative_base()
  
      class Property(Base):
          __tablename__ = 'properties'
          id = Column(Integer, primary_key=True)
          name = Column(String)
          value = Column(String)
  
      engine = create_engine('sqlite:///properties.db')
      Base.metadata.create_all(engine)
      Session = sessionmaker(bind=engine)
      session = Session()
  
      fixture_file = Path(fixture_path) / 'fixture.json'
      if not fixture_file.exists():
          return 0
  
      with open(fixture_file, 'r') as f:
          data = json.load(f)
  
      properties = data.get('properties', [])
      for prop in properties:
          new_property = Property(name=prop['name'], value=prop['value'])
          session.add(new_property)
  
      session.commit()
      return len(properties)
  