A type of database that organise data into structured tables of rows and columns.
Each row represent a unique record and each column represents an attribute.
A table requires a fixed Schema, meaning that the structure of the data must be predefined.
Tables are linked to each other using Primary Keys and Foreign Keys.
Uses SQL for querying, adding, and editing data.
Examples
Structure
| id | username | first_name | last_name |
|---|---|---|---|
| 1 | admin | admin | admin |
| 2 | test | test | test |
| 3 | sa | super | admin |
with the primary key id.
| id | user_id | date | content |
|---|---|---|---|
| 1 | 2 | 01-01-2021 | Welcome … |
| 2 | 2 | 02-01-2021 | This is the … |
| 3 | 1 | 02-01-2021 | Reminder: … |
with the primary key id and the foreign key user_id, that references the primary key in the users table.