Added part 2 content

mariadb_python_sqlalchemy/part_2/onboarding/base.py

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+from sqlalchemy import create_engine
+from sqlalchemy.ext.declarative import declarative_base
+from sqlalchemy.orm import sessionmaker
+
+engine = create_engine("mariadb+mariadbconnector://app_user:Password123!@127.0.0.1:3306/planning")
+Session = sessionmaker(bind=engine)
+
+Base = declarative_base()

mariadb_python_sqlalchemy/part_2/onboarding/contact_details.py

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+from sqlalchemy import Column, String, Integer, ForeignKey
+from sqlalchemy.orm import relationship, backref
+
+from base import Base
+
+class ContactDetails(Base):
+    __tablename__ = 'contact_details'
+
+    id = Column(Integer, primary_key=True)
+    phone_number = Column(String(length=12))
+    address = Column(String(length=100))
+    employee_id = Column(Integer, ForeignKey('employees.id'))
+    employee = relationship("Employee", backref=backref("contact_details", uselist=False))
+
+    def __init__(self, phone_number, address, employee):
+        self.phone_number = phone_number
+        self.address = address
+        self.employee = employee

mariadb_python_sqlalchemy/part_2/onboarding/department.py

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+from sqlalchemy import Column, String, Integer, ForeignKey
+from sqlalchemy.orm import relationship
+
+from base import Base
+
+class Department(Base):
+    __tablename__ = 'departments'
+
+    id = Column(Integer, primary_key=True)
+    name = Column(String(length=50))
+    employees = relationship("Employee")
+
+    def __init__(self, name):
+        self.name = name

mariadb_python_sqlalchemy/part_2/onboarding/employee.py

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+from sqlalchemy import Column, String, Integer, Boolean, ForeignKey
+from sqlalchemy.orm import relationship, backref
+
+from base import Base
+
+class Employee(Base):
+    __tablename__ = 'employees'
+
+    id = Column(Integer, primary_key=True)
+    department_id = Column(Integer, ForeignKey('departments.id'))
+    firstname = Column(String(length=100))
+    lastname = Column(String(length=100))
+    active = Column(Boolean, default=True)
+    department = relationship("Department", back_populates="employees")
+    
+    #contact_details = relationship("ContactDetails", backref=backref("contact_details", uselist=False))
+
+    def __init__(self, firstname, lastname, department):
+        self.firstname = firstname
+        self.lastname = lastname
+        self.department = department

mariadb_python_sqlalchemy/part_2/onboarding/load.py

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+from datetime import date
+
+from base import Session, engine, Base
+from employee import Employee
+from project import Project 
+from department import Department
+from contact_details import ContactDetails
+
+# Generate database schema
+Base.metadata.create_all(engine)
+
+# Create a new session
+session = Session()
+
+# Create projects
+project_1 = Project("Project 1", "Project 1 description", date(2021, 5, 31))
+project_2 = Project("Project 2", "Project 2 description", date(2021, 4, 30))
+project_3 = Project("Project 3", "Project 3 description", date(2021, 6, 15))
+
+# Create departments
+dept_marketing = Department("Marketing")
+dept_engineering = Department("Engineering")
+
+# Create employees
+emp_john = Employee("John", "Locke", dept_marketing)
+emp_kate = Employee("Kate", "Austin", dept_engineering)
+emp_jack = Employee("Jack", "Shepherd", dept_marketing)
+emp_ben = Employee("Ben", "Linus", dept_marketing)
+emp_sun = Employee("Sun", "Kwan", dept_engineering)
+
+# Add employees to projects
+project_1.employees = [emp_john,emp_kate]
+project_2.employees = [emp_jack,emp_ben,emp_sun]
+project_3.employees = [emp_john,emp_kate,emp_jack,emp_ben,emp_sun]
+
+# Create contact details
+cd_john = ContactDetails("417 315 2531", "123 S Main ST", emp_john)
+cd_kate = ContactDetails("417 315 2533", "124 S Main ST", emp_kate)
+cd_jack = ContactDetails("417 315 2534", "125 S Main ST", emp_jack)
+cd_ben = ContactDetails("417 315 2535", "126 S Main ST", emp_ben)
+cd_sun = ContactDetails("417 315 2536", "127 S Main ST", emp_sun)
+
+
+# Persist data
+session.add(project_1)
+session.add(project_2)
+session.add(project_3)
+
+session.add(dept_marketing)
+session.add(dept_engineering)
+
+session.add(cd_john)
+session.add(cd_kate)
+session.add(cd_jack)
+session.add(cd_ben)
+session.add(cd_sun)
+
+session.commit()
+session.close()

mariadb_python_sqlalchemy/part_2/onboarding/project.py

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+from sqlalchemy import Column, String, Integer, Date, Table, ForeignKey
+from sqlalchemy.orm import relationship
+
+from base import Base
+
+projects_employees_association = Table(
+    'projects_employees', Base.metadata,
+    Column('project_id', Integer, ForeignKey('projects.id')),
+    Column('employee_id', Integer, ForeignKey('employees.id'))
+)
+
+class Project(Base):
+    __tablename__ = 'projects'
+
+    id = Column(Integer, primary_key=True)
+    name = Column(String(length=100))
+    description = Column(String(length=500))
+    due_date = Column(Date)
+    employees = relationship("Employee", secondary=projects_employees_association)
+
+    def __init__(self, name, description, due_date):
+        self.name = name
+        self.description = description
+        self.due_date = due_date

mariadb_python_sqlalchemy/part_2/onboarding/query.py

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+from base import Session
+from project import Project
+from employee import Employee
+from department import Department
+
+session = Session()
+
+# Get all projects
+projects = session.query(Project).all()
+
+print('### Projects ###')
+for project in projects:
+    print(project.name)
+    for employee in project.employees:
+        print(f'  - {employee.firstname} {employee.lastname} ({employee.department.name})')
+
+
+# Get all departments
+departments = session.query(Department).all()
+
+print('### Departments ###')
+for department in departments:
+    print(department.name)
+    for employee in department.employees:
+        print(f'  - {employee.firstname} {employee.lastname}')
+
+# John Lock projects
+john_lock_projects = session.query(Project) \
+                            .join(Employee, Project.employees) \
+                            .filter(Employee.firstname == 'John') \
+                            .all()
+
+print('### John Locke projects ###')
+
+for project in john_lock_projects:
+    print(f'- {project.name}')