Guided Notes
Extract: SQL Databases & APIs
Querying SQLite with pandas, SQLAlchemy engines, and pulling data from web APIs like the World Bank's.
Data in SQL databases
Slide 1 / 5Most company data lives in relational databases — MySQL, PostgreSQL, SQL Server, or SQLite. Extracting from them means running a SQL query and bringing the result into pandas.
SQLite stores an entire database in one file (or in memory), and Python includes the sqlite3 module to talk to it — perfect for learning and small projects.
For big tables, let the database do the filtering: query only the rows and columns you need instead of reading everything into Python.