Flask Database Operations: A Beginner's Guide to SQLAlchemy ORM

ORM solves the maintenance difficulties of directly writing SQL in web development by simplifying operations through mapping database table structures with Python objects. Flask + SQLAlchemy is a commonly used combination, and you need to install `flask` and `flask-sqlalchemy` first. During initialization, configure the SQLite database path (e.g., `sqlite:///mydatabase.db`) and disable modification tracking. Define model classes (such as User) that inherit from `db.Model`, with class attributes corresponding to table fields (including primary keys and constraints). Use `db.create_all()` to automatically generate the tables. Core operations are session-based (`db.session`): creation (`add` + `commit`), reading (`query.all()`/`filter_by()`/`get()`), updating (modify attributes + `commit`), and deletion (`delete` + `commit`). After mastering this process, you can extend to databases like MySQL and explore advanced features such as relationship models.