@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)
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.
Good. Very professional
alotan2acs 3 months ago
May be filmed with a stone, but it's a good instructional video
marleymusic217 3 months ago
Very much appreciated these videos, very helpfull.
AeolusMN 4 months ago
thankyou, this video has really helped me understand 2NF, just a quick question though, what is a concatenated key?
rocknrollzing 8 months ago
@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)
gvimontslice 8 months ago
I am loving the videos Dr. Langer, thank you for the time and effort you have put in.
mookjais 1 year ago
very good explenation
sl2mmer 1 year ago
not only the price can change (in LDM 11 last clip)
any attribute can be changed.
dustonly1986 1 year ago
Thank you so much ! I really appreciate your efforts in explaining this, and thanks for sharing these videos .
DrCOMPUT3R 2 years ago
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.
Muddogg87 2 years ago
excellent explanation of the subject
mav252 2 years ago
Thanks for this lecture!
darfunkelidas 2 years ago
Thanks so much! Please come and take over my database teacher's job.... :)
jokidzzz 2 years ago
Wow! the lecture was incredibly clear - I can't thank you enough.
linxon2 3 years ago