Table Relationship Types: One-to-One, One-to-Many, Many-to-Many
Relational databases connect tables through three fundamental relationship types: one-to-one, one-to-many, and many-to-many. Each follows the third normal form (3NF) principles with specific key and constraint strategies.
1. One-to-One Relationship
One entity is linked to exactly one instance of another entity. The primary table holds an id as ...
Posted on Sat, 10 Oct 2026 16:49:46 +0000 by bombayduck
Understanding MySQL Constraints
Constraints are rules applied to table columns to restrict the data that can be stored. Their purpose is to ensure data correctness, validity, and integrity within the database.
Categories of Constraints
NOT NULL: Ensures a column cannot have a NULL value.
UNIQUE: Guarantees that all values in a column are different.
PRIMARY KEY: Uniquely iden ...
Posted on Wed, 29 Jul 2026 16:15:57 +0000 by DwarV