Logic Data Modeling 6 - 2nd Normal Form

Lecture by Dr. Art Langer, author. Analysis & Design of Information Systems (3nd Ed), Langer, Springer-Verlag 2007 (ISBN978-1-844628-654-4)

Category:

Education

Tags:

• Logical
• Data
• Modeling
• Normalization
• Database
• Design

[rocknrollzing]

thankyou, this video has really helped me understand 2NF, just a quick question though, what is a concatenated key?

[gvimontslice]

@rocknrollzing - A "concatenated key" -- sometimes also called a "compound key" -- is simply a primary key structure that is composed of two or more data elements that when taken together will uniquely identify an instance of the entity under consideration. This form of key structure will appear within associative entities that resolve so-called "many-to-many" relationships. (E.g. Entities ORDER and ITEM have an m:n relationship that is resolved via the entitie called: ORDER ITEM)

[alotan2acs]

Good. Very professional

[marleymusic217]

May be filmed with a stone, but it's a good instructional video

[AeolusMN]

Very much appreciated these videos, very helpfull.

[mookjais]

I am loving the videos Dr. Langer, thank you for the time and effort you have put in.

[sl2mmer]

very good explenation

[dustonly1986]

not only the price can change (in LDM 11 last clip)

any attribute can be changed.

[DrCOMPUT3R]

Thank you so much ! I really appreciate your efforts in explaining this, and thanks for sharing these videos .

[Muddogg87]

Your explanations are really helpful, I'm studying the module: 'Relational Databases, Design and Use' as part of my University course and these tutorials really clarify the course material.

Thankyou.