Prerequisite – ER Model
Strong entity is not dependent of any other entity in schema. Strong entity always has primary key. Strong entity is represented by single rectangle. Two strong entity’s relationship is represented by single diamond.
Various strong entities together makes the strong entity set.
Weak entity is depend on strong entity to ensure the existance of weak entity. Like strong entity weak entity does not have any primary key, It has partial discriminator key. Weak entity is represented by double rectangle.
The relation between one strong and one weak entity is represented by double diamond.
Difference between Strong and Weak Entity:
|S.NO||Strong Entity||Weak Entity|
|1.||Strong entity always has primary key.||While weak entity has partial discriminator key.|
|2.||Strong entity is not dependent of any other entity.||Weak entity is depend on strong entity.|
|3.||Strong entity is represented by single rectangle.||Weak entity is represented by double rectangle.|
|4.||Two strong entity’s relationship is represented by single diamond.||While the relation between one strong and one weak entity is represented by double diamond.|
|5.||Strong entity have either total participation or not.||While weak entity always has total participation.|
- Weak Entity Set in ER diagrams
- Difference between RAM and ROM
- Difference between CPU and GPU
- Difference between C and C#
- Difference between LAN and MAN
- Difference between H.323 and SIP
- Difference between CD and DVD
- Difference between TDM and FDM
- Difference between MP4 and MP3
- Difference between LED and LCD
- Difference between ++*p, *p++ and *++p
- Difference between LAN and WAN
- Difference between JSP and ASP
- Difference between PNG and GIF
- Web 1.0, Web 2.0 and Web 3.0 with their difference
If you like GeeksforGeeks and would like to contribute, you can also write an article using contribute.geeksforgeeks.org or mail your article to email@example.com. See your article appearing on the GeeksforGeeks main page and help other Geeks.
Please Improve this article if you find anything incorrect by clicking on the "Improve Article" button below.