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A sample entity–relationship diagram. One of the most common types of conceptual schemas is the ER (entity–relationship model) diagrams. Attributes in ER diagrams are usually modeled as an oval with the name of the attribute, linked to the entity or relationship that contains the attribute.
It occurs when a (master) table links to multiple tables in a one-to-many relationship. The issue derives its name from the visual appearance of the model when it is drawn in an entity–relationship diagram, as the linked tables 'fan out' from the master table. This type of model resembles a star schema, which is a common design in data ...
The enhanced entity–relationship (EER) model (or extended entity–relationship model) in computer science is a high-level or conceptual data model incorporating extensions to the original entity–relationship (ER) model, used in the design of databases.
Code diagrams (level 4): provide additional details about the design of the architectural elements that can be mapped to code. The C4 model relies at this level on existing notations such as Unified Modelling Language (UML) , Entity Relation Diagrams (ERD) or diagrams generated by Integrated Development Environments (IDE) .
Overview of a data-modeling context: Data model is based on Data, Data relationship, Data semantic and Data constraint. A data model provides the details of information to be stored, and is of primary use when the final product is the generation of computer software code for an application or the preparation of a functional specification to aid a computer software make-or-buy decision.
Data structure diagram and a data dictionary. A data structure diagram (DSD) is a data model or diagram used to describe conceptual data models by providing graphical notations which document entities and their relationships, and the constraints that bind them.
To produce the logical specification, the analyst builds the required logical models for both the data-flow diagrams (DFDs) and the Logical Data Model (LDM), consisting of the Logical Data Structure (referred to in other methods as entity relationship diagrams) and full descriptions of the data and its relationships. These are used to produce ...
A data structure diagram is a diagram type that is used to depict the structure of data elements in the data dictionary. The data structure diagram is a graphical alternative to the composition specifications within such data dictionary entries. [1] The data structure diagrams is a predecessor of the entity–relationship model (E–R model