A collection of tools for describing data, relationships, and constraints.
Examples
Relational Model
Data is organized into tables and relationships.
Entity-Relationship Model
Data is organized into entities with attributes and relationships. Used only in the design phase. Used to implement relational model. Explained more on Entity-Relationship Model
Object-Relational Model
Extends relational model by adding object-oriented features. Attributes can be complex.
- User defined types
- Inherited subtypes
- Inherited tables
- Complex attributes such as arrays and sets
Semistructured Model
Represents data that does not conform to a rigid schema but has some organizational structure. Examples include XML and JSON formats, which use tags or key-value pairs to indicate data hierarchy and relationships.
Document-Oriented Model
Data is organized into documents with fields and values.
Network Model
Data is organized into nodes and links, similar to a graph.
Hierarchical Model
Data is organized into parent-child relationships.