geomon/db/fb_models.py

72 lines
2.3 KiB
Python

'''
Tutorial link: https://docs.sqlalchemy.org/en/latest/orm/tutorial.html
Sqlalchemy version: 1.2.15
Python version: 3.7
'''
import os
import datetime
from sqlalchemy import (create_engine, Column, Integer,
String, ForeignKey, Time, Date)
from sqlalchemy.ext.declarative import declarative_base
from sqlalchemy.orm import sessionmaker, relationship
import sqlalchemy.orm.session
Base = declarative_base()
class Catena(Base):
""" catena class """
__tablename__ = 'CATENE'
id = Column('CHIAVE', Integer, primary_key=True)
name = Column('NOME', String)
# observations = relationship('FbObservation')
observations = relationship('FbObservation', back_populates="catena", lazy=True)
def __repr__(self): # optional
return f'Catena {self.name}'
class FbObservation(Base):
""" FbObservation class """
__tablename__ = 'DATI_ACQUISITI'
# id = Column(Integer, primary_key=True) # obligatory
pitch = Column('PITCH', String)
roll = Column('ROLL', String)
ora = Column('ORA', Time, primary_key=True)
sensore = Column('SENSORE', Integer, primary_key=True)
data = Column('DATA', Date, primary_key=True)
temperature = Column('TEMPERATURA', String)
chiave_id = Column('CATENA', Integer, ForeignKey('CATENE.CHIAVE'), primary_key=True, nullable=True)
catena = relationship(
"Catena", back_populates="observations", lazy="joined")
# chiave_id = Column('CATENA', Integer, ForeignKey('CATENE.CHIAVE'))
# catena = relationship("Catena", lazy="joined", foreign_keys=[chiave_id])
def __repr__(self): # optional
return f'FbObservation {self.roll}'
@property
def result_time(self):
''' Create a datetime object '''
start_datetime = datetime.datetime.combine(self.data, self.ora)
return start_datetime
def create_session() -> sqlalchemy.orm.session:
"""Return the sum of x and y."""
# engine = create_engine('sqlite:///:memory:')
db_user = os.environ.get("FDB_DBUSER")
db_password = os.environ.get("FDB_DBPASSWORD")
db_url = os.environ.get("FDB_DBURL")
engine = create_engine(
"firebird+fdb://" + db_user + ":" + db_password + "@" + db_url)
session_maker = sessionmaker(bind=engine)
session = session_maker()
# Base.metadata.create_all(engine)
return session