Cardinality The number of entities – to which another entity can be associated through a relationship The diagrams on the right show, in order: one-to-one one-to-many many-to-one many-to-many Examples illustrating the use of each notation Chen notation high-level entities only – Chen notation detailed – Crow’s foot notation detailed, including data type –
Cardinality – The number of entities to which another entity can be associated through a relationship The diagrams on the right show, in order: one-to-one one-to-many many-to-one many-to-many Examples illustrating the use of each notation Chen notation – high-level entities only Chen notation – detailed Crow’s foot notation – detailed, including data type
Informatics_examination_ER_Conventions.docx