Recap of RDBMS Concepts¶
Let us recap some of the RDBMS concepts before performing CRUD Operations. We will develop programs to interact with Database using Postgres which is RDBMS Database.
RDBMS stands for Relational Database Management System.
Tables will be normalized to ensure that records are uniquely identifiable, related with each other, etc.
Most of the database tables supporting transactional applications are either in 3rd Normal Form or Boyce Codd Normal Form.
There are different types of relationships between tables.
one to one
one to many
many to one
many to many (typically implemented via bridge tables)
Tables typically contain different type of constraints.
Primary Key Constraints
Unique Key Constraints
Not Null Constraints
Foreign Key Constraints referencing Primary Key Constraints of its parent table.
and more
Data Model for Oracle HR Database
Data Model for Cloudera’s Sample Retail Database.