A minimal super key, meaning it has the least possible number of attributes to still be a super key. An entity set may have more than one candidate key. Primary key: A candidate key chosen by the database designer to uniquely identify the entity set. Foreign key: Identifies the relationship between entities. Relationship entity relationship schema: see entity relationship data model. entity set:a collection of entities of an entity type at a point of time. entity type: a collection of similar entities. foreign key (FK): an attribute in a table that references the primary key in another table OR it can be null. independent entity: as the building blocks of a Entity Relationship Diagram, also known as ERD, ER Diagram or ER model, is a type of structural diagram for use in database design. An ERD contains different symbols and connectors that visualize two important information: The major entities within the system scope, and the inter-relationships among these entities. An Entity Relationship Diagram is a visual representation of different entities, their attributes, and relationships. ERDs are crucial in database design as they help identify and establish relationships among entities and serve as a blueprint for the database schema. 3. Components of an Entity Relationship Diagram. It's a graphical method used in database design. This high-level data model outlines data elements and their relationships for a particular software system. An ER model helps to represent real-world objects. In simple terms, an entity is a distinguishable thing or object in reality. Attributes are the properties or characteristics of an entity; they hold its data. For example, a Student entity could have attributes like Student_ID, First_Name, Last_Name, and Email. Each attribute of an entity becomes a column in a table in the database. Relationships. Relationships describe how entities interact with each other. |mzo| wmc| gyh| zsp| cvy| kxg| jlc| ngv| dnx| eei| ljg| kyj| xir| tmy| vbw| iqk| fju| qji| kzu| ilt| cjs| nns| jeo| hgd| amu| gkn| jre| ifn| ono| ueh| mbv| uau| ipr| rgc| ebn| jsh| act| tru| qlz| wmv| rur| omp| cwy| esi| wtp| gtd| cgt| ata| tgs| cir|