Python Classroom notes 24/May/2026

Database Layer

• We need to figure out a way to interact with database
• From the design perspecive we have two options
  • Executing SQL Statements
  • ORM Frameworks

Python to Database using raw sql statements

• Databases: On a larger note we have two types of databases

  • Relational Databases:

    • Here data is stored in tabular formats and tables can have relationships between them
      

    • There are two types of keys

      • primary key
      • foreign key
    • To interact with these databases there is a standard SQL (Structured Query Language)
    • This standard is implemented by database management softwares
      • ORACLE -> PL/SQL
      • SQL SERVER -> t-sql
      • Postgres
      • mysql
    • SQL Standard
      • CREATE
      • UPDATE
      • DELETE
      • Retrieve/SELECT
      • NO-SQL

• Prompt for SQL

you are an expert in database,
Help me in learning and writing sql statements of postgres database for a simple school management system

Explain Each topic, give some examples wait, then go to next

SQLite

• This is a database which stores all of its data in a file

• Python standard library supports this

• Refer Here for code done and watch classroom recording for sqlite and postgres related db connection and executing queries

ORM (Object Relational Mapping)

• ORM gives

  • Cleaner code
  • Reusable models
  • relationships
  • migrations
  • type safety
  • abstracts db engine

• Popular ORM Frameworks

  • SQLAlchemy
  • Django ORM

SQL ALchemy

• Refer Here for the changes

• Refer Here for orm posgtres and Refer Here for direct query executions

• Refer Here for direct of sqlite and Refer Here for orm version

Authentication and Authorization