Logical Diagram Notation - Information Engineering Notation
899773Nov 11 2011 — edited Oct 18 2012I'm a little confused about the Logical Diagram Relational Properties diagram. In a parent/child relationship where parent is required and children are optional, the Source to Target Cardinality must be set to * and Target to Source Cardinality to 1. Source Optional pertains to the Source and is unchecked and Target Optional is checked. A bit inconsistent and untuitive to me to have one Source setting describe the source and the other Source setting describe the Target, but fine. Those settings display correctly in Barker and Bachman notation.
If, however, you switch the notation to Information Engineering Notation, the optional settings are revered and display incorrectly. Checking Source Optional controls the optionality of the Target and visa versa.