The Meaning of Null in Databases and Programming Languages

TL;DR

This paper explores the ambiguous concept of null in relational databases and programming languages, aiming to clarify its meaning and reduce user confusion through analysis and suggestions.

Contribution

It provides an examination of null semantics in databases and proposes suggestions to clarify its meaning and usage.

Findings

Null semantics are often misunderstood by users and authors.

Clarifying null's meaning can improve database usability.

Proposed suggestions may reduce confusion about null.

Abstract

The meaning of null in relational databases is a major source of confusion not only among database users but also among database textbook writers. The purpose of this article is to examine what database nulls could mean and to make some modest suggestions about how to reduce the confusion.