Database Key Terms - Digi Sol

Relational database

A collection of data tables linked by Primary Keys and Foreign Keys. Different from a spreadsheet, which is a single table.

Table

A set of rows and columns that stores one type of thing (e.g. Students, Orders, Items).

Record (row)

A row in a table — represents a single instance of whatever the table stores (one student, one order).

Field (column)

One column in a table — one piece of information recorded about each record (e.g. Name, YearLevel).

Primary Key (PK)

A field (or small group of fields) that uniquely identifies each record in the table. Cannot be NULL and cannot be duplicated. Usually underlined on a diagram.

Foreign Key (FK)

A field in one table that matches the Primary Key of another table. This creates the link (relationship) between the two tables, Often written with (FK) next to it.

Relationship

The link between two tables, created when a PK in one table is referenced as an FK in another. Shown on a diagram with a line connecting the two fields.

One-to-many

A relationship where ONE record in Table A can be linked to MANY records in Table B (e.g. one student can have many orders, but each order belongs to only one student).