0x0F-python-object_relational_mapping

Python - Object-relational mapping

In this project, I learned about how object-relational mapping is used for database scripting. I became familiar with using MySQLdb and SQLAlchemy to query, create, edit, and delete tables in MySQL.

Tasks 📃

• 0. Get all states

  • 0-select_states.py: Python script that uses MySQLdb to list all states in the database hbtn_0e_0_usa.
  • Usage: ./0-select_states.py <mysql username> <mysql password> <database name>.
  • Results are ordered by ascending states.id.

• 1. Filter states

  • 1-filter_states.py: Python script that uses MySQLdb to list all states with names starting with N in the database hbtn_0e_0_usa.
  • Usage: ./1-filter_states.py <mysql username> <mysql password> <database name>.
  • Results are ordered by ascending states.id.

• 2. Filter states by user input

  • 2-my_filter_states.py: Python script that uses MySQLdb to display all values matching a given name in the states table of the database hbtn_0e_0_usa.
  • Usage: ./2-my_filter_states.py <mysql username> <mysql password> <database name> <state name searched>.
  • Results are ordered by ascending states.id.
  • Uses string formatting to construct the SQL query.

• 3. SQL Injection...

  • 3-my_safe_filter_states.py: Python script that uses MySQLdb to display all values matching a given name in the states table of the database hbtn_0e_0_usa.
  • Usage: ./3-my_safe_filter_states.py <mysql username> <mysql password> <database name> <state name searched>.
  • Results are ordered by ascending states.id.
  • Safe from SQL injections.

• 4. Cities by states

  • 4-cities_by_state.py: Python script that uses MySQLdb to list all cities from the database hbtn_0e_4_usa.
  • Usage: ./4-cities_by_state.py <mysql username> <mysql password> <database name>.
  • Results are ordered by ascending cities.id.

• 5. All cities by state

  • 5-filter_cities.py: Python script that uses MySQLdb to list all cities of a given state in the database hbtn_0e_4_usa.
  • Usage: ./5-filter_cities.py <mysql username> <mysql password> <database name>.
  • Results are sorted by ascending cities.id.

• 6. First state model

  • model_state.py: Python module defining a class State that inherits from SQLAlchemy Base and links to the MySQL table states.

• 7. All states via SQLAlchemy

  • 7-model_state_fetch_all.py: Python script that uses SQLAlchemy to list all State objects from the database hbtn_0e_6_usa.
  • Usage: ./7-model_state_fetch_all.py <mysql username> <mysql password> <database name>.
  • Results are sorted by ascending states.id.

• 8. First state

  • 8-model_state_fetch_first.py: Python script that uses SQLAlchemy to print the first State object from the database hbtn_0e_6_usa, ordered by states.id.
  • Usage: ./8-model_state_fetch_first.py <mysql username> <mysql password> <database name>.
  • If the states table is empty, prints Nothing.

• 9. Contains a

  • 9-model_state_filter_a.py: Python script that uses SQLAlchemy to list all State objects that contain the letter a in the database hbtn_0e_6_usa.
  • Usage: ./9-model_state_filter_a.py <mysql username> <mysql password> <database name>.
  • Results are ordered by ascending states.id.

• 10. Get a state

  • 10-model_state_my_get.py: Python script that uses SQLAlchemy to print the id of the State object with name matching that passed as argument in the database hbtn_0e_6_usa.
  • Usage: ./10-model_state_my_get.py <mysql username> <mysql password> <database name> <state searched name>.
  • Displays the id of the matched State.
  • If no match is found, prints Not found.

• 11. Add a new state

  • 11-model_state_insert.py: Python script that uses SQLAlchemy to add the State object "Louisiana" to the database hbtn_0e_6_usa.
  • Usage: ./11-model_state_insert.py <mysql username> <mysql password> <database name>.
  • Prints the id of the new State after creation.

• 12. Update a state

  • 12-model_state_update_id_2.py: Python script that uses SQLAlchemy to change the name of the State object with id = 2 in the database hbtn_0e_6_usa to "New Mexico".
  • Usage: ./12-model_state_update_id_2.py <mysql username> <mysql password> <database name>.

• 13. Delete states

  • 13-model_state_delete_a.py: Python script that uses SQLAlchemy to delete all State objects with a name containing the letter a from the database hbtn_0e_6_usa.
  • Usage: ./13-model_state_delete_a.py <mysql username> <mysql password> <database name>.

• 14. Cities in state

  • model_city.py: Python module defining a class City that inherits from SQLAlchemy Base and links to the MySQL table cities.
    • Includes class attribute state_id that is a foreign key to states.id.
  • 14-model_city_fetch_by_state.py: Python script that uses SQLAlchemy to list all City objects in the database hbtn_0e_14_usa.
  • Usage: ./14-model_city_fetch_by_state.py <mysql username> <mysql password> <database name>.
  • Results are sorted by ascending cities.id.

• 15. City relationship

  • relationship_state.py: Python module defining a class State that inherits from SQLAlchemy Base and links to the MySQL table states.
    • Identical to the State class defined in model_state.py.
    • Includes class attribute classes that represents a relationship with the class City. If the State object is deleted, all linked City objects are also deleted. State objects are backreferenced to City objects as state.
  • relationship_city.py: Python module defining a class City that inherits from SQLAlchemy Base and links to the MySQL table cities.
    • Identical to the City class defined in model_city.py.
  • 100-relationship_states_cities.py: Python script that uses SQLAlchemy to add the State "California" with City "San Francisco" to the database hbtn_0e_100_usa.
  • Usage: ./100-relationship_states_cities.py <mysql username> <mysql password> <database name>.
  • Uses the cities relationship for all State objects.

• 16. List relationship

  • 101-relationship_states_cities_list.py: Python script that uses SQLAlchemy to list all State and corresponding City objects in the database hbtn_0e_101_usa.
  • Usage: ./101-relationship_states_cities_list.py <mysql username> <mysql password> <database name>.
  • Uses the cities relationship for all State objects.
  • Results are sorted by ascending states.id and cities.id.

• 17. List city

  • 102-relationship_cities_states_list.py: Python script that uses SQLAlchemy to list all City objects from the database hbtn_0e_101_usa.
  • Usage: ./102-relationship_cities_states_list.py <mysql username> <mysql password> <database name>.
  • Uses the state relationship to access the State objects linked to City objects.
  • Results are sorted by ascending cities.id.

• Author ✒️

• Prince Solomon princexz

Acknowledgements 🙏

All work contained in this project was completed as part of the curriculum for ALX Africa SE. ALX Africa is an online full-stack software engineering program that prepares students for careers in the tech industry using project-based peer learning. For more information, visit this link.