: Defines the numerical relationship between entities, such as one-to-one , one-to-many , or many-to-many . Why ERDs are Useful
: They serve as high-level documentation of a system’s information architecture. Levels of Abstraction AZ erdЕ‘rЕ‘l
: The most detailed version, showing actual table structures, data types, and constraints for a specific database management system. : Defines the numerical relationship between entities, such
An is a visual report used to design and model relational databases by illustrating how different "entities" (like people, objects, or concepts) relate to one another within a system. Core Components of an ERD An is a visual report used to design
: Represented as rectangles, these are the "nouns" of the system, such as Customer , Order , or Product .
: Adds more detail, defining attributes and keys but remaining independent of a specific database technology.
: They act as a blueprint for developers to build the actual physical database.