Database Design

22 focused lessons on entities and relationships, normalization, table creation and data changes. Begin with diagrams and visual questions without writing SQL, then use an isolated SQLite lab. The academic path places SQL query foundations between schema creation and data changes.

The plan and the current data
Entities, attributes and keys
How many links are allowed and required?
From 1:N to a foreign key
M:N and a bridge table
Weak entities and local keys
Recursive relationships: one type, two roles
ISA specialization: coverage and overlap
ER aggregation: a relationship as a unit
Dependencies, anomalies and first normal form
2NF: separate partial-key dependencies
3NF and meaning-preserving decomposition
Build a first table in the schema lab
Keys, uniqueness and required values
CHECK and DEFAULT: rules and initial values
Composite foreign keys and deletion actions
Change an existing schema without losing data
INSERT: add rows deliberately
UPDATE: change only the intended row
DELETE: remove rows, not the table
One transaction: COMMIT or ROLLBACK
From diagram to database: a small shop