mysql - Which one is ER diagram - Stack Overflow
2016年5月11日 · Your first diagram is a proper ER diagram, using the concepts and notation developed by Peter Chen in his paper The Entity-Relationship Model - Toward a Unified View …
Entity Relationship Diagram. How does the IS A relationship …
Assuming the relationship is mandatory (as you said, a person has to be a student or a teacher) and disjoint (a person is either a student or a teacher, but not both), the best solution is with 2 …
How to generate an entity-relationship (ER) diagram using Oracle …
2011年7月5日 · I just created a relational model diagram via the menu: File->Data Modeler->Import->Data Dictionary.... I also have the stand-alone Data Modeler, which does the same …
ER-Diagram: Ternary Relationship - How to read properly?
Im not quite sure how to read ternary relationships within a ER-Diagram. Lets say this is the ternary relationship that is given. What can I interpret out of that? It says that you have to put …
How to relate these tables in an ER Diagram? - Stack Overflow
2017年4月11日 · Here is an ER diagram (conceptual model) showing a many-to-many relationship between LineItems and Designs. For simplicity I left out non-key attributes. I also …
Generate an E-R Diagram by reverse-engineering a database
2014年5月7日 · By the way, I strongly suggest using "circo" or "twopi" to plot the diagram as opposed to plain "dot" or even "neato" - at least in my experience produces much pleasant …
How can I implement IF condition in ER diagram? - Stack Overflow
2022年10月1日 · I have the following ER diagrams: customer starts a transaction with account. Bank updates watch_list. I'm new to ER diagram and I want to add an alert system in banking …
Create database E-R diagram with D3js - Stack Overflow
2014年1月17日 · Hello VividD. Thank you for your interest. The basic purpose of this E-R diagram is to allow users to browse the relationships between tables and I also plan to highlight the …
How to identify a strong vs weak relationship on ERD?
2013年5月21日 · In an ER diagram, I believe when the relationship is strong, i.e., the primary_key of the parent forms a composite or non-composite primary_key in the child entities, we use a …
Translating relationship attributes from ER diagram into SQL
2015年2月10日 · So far I've got an ER diagram drawn up which I think is correct: I can get the basics (e.g. creating a Student table etc) but I'm having trouble getting my head around how to …