Logical Data Modeling - Constraint
Table of Contents
1 - About
A constraint is a metadata rule that expresses a condition or restriction in natural language text or in a machine readable language for the purpose of declaring some data or process semantics.
2 - Articles Related
3 - Example
- Structure: All rows must have the same number of columns
- Data domain: All value in a column must have the same type
- Relationship: A child cannot have three parents
- Business rule: A product cannot be send to a client that was not verified.
4 - Documentation / Reference
- Unified Modeling Language (UML) - 2.5.1 - chapter 7.8.3