31-03-2017, 10:48 AM
An entity-relationship diagram (ER) is used to show the structure of a business database. ERD represents data as objects (entities) that are connected with symbols of standard relationships that illustrate an association between entities. ERD, there is a wide range of ERD notations used by database architects to reflect relationships between data entities. According to the crow foot notation relationships are drawn as simple labeled lines that designate certain types of relationship. Crowfoot notation is the most commonly used ERD standard, due to the greater legibility of the diagrams, with a more precise use of space on the page.
![[Image: Chen-ERD--sample.png]](http://www.conceptdraw.com/How-To-Guide/picture/Chen-ERD--sample.png)