Recommended schema websites?

[GopherUK]

Hi,

Just wondering if there is a website out there that gives professional DB schemas? I am sure I saw one here a while ago but I cant seem to find the thread for it.

Any help would be greatly appreciated.

 

[jackd]

There are free data models at http://www.databaseanswers.org

Hope it helps.

 

[GopherUK]

Thank you very much.

I am also going through the DataPig stuff... very useful indeed.

 

[jackd]

You may also find these useful.

These free video tutorials describe the processes of data modelling, normalization and entity relationship diagramming. There are other videos, but this group is by the same presenter and covers an example situation.

http://www.youtube.com/watch?v=IiVq8M5DBkk Logical data modeling

http://www.youtube.com/watch?v=BGMwuOtRfqU Candidate key

http://www.youtube.com/watch?v=ZiB-BKCzS_I Normalization

http://www.youtube.com/watch?v=pJ47btpjAhA Normalization example

http://www.youtube.com/watch?v=q3Wg2fZENK0 1st Normal form

http://www.youtube.com/watch?v=vji0pfliHZI 2nd Normal form

http://www.youtube.com/watch?v=HH-QR7t-kMo 3rd Normal form

http://www.youtube.com/watch?v=q1GaaGHHAqM E_R Diagramming

http://www.youtube.com/watch?v=lXAGQ8vmhCY ERD Part 2

 

[GopherUK]

Thanks again. Very useful.

Are there any other resources you would recommend for properly understanding professional-level Access development? I am very experienced with Excel and VBA for Excel, understanding best industry practices, but I find it hard to get the resources I need to make sure my applications are of the highest standard.

 

[jackd]

You may find related info here
http://www.utteraccess.com/forum/Access-Tutorials-f46.html
http://allenbrowne.com/tips.html
http://www.access-programmers.co.uk/forums/showthread.php?p=1152269

 

[GopherUK]

Thanks.

 

[GopherUK]

Hoping I am not asking things I should already know (I am just trying to get some quick answers to things I am unsure of)...

When creating a many-to-many relationship via a junction table, am I correct in think that it should not include an autonumber field as the PK should be a concatenation of the PKs/IDs of the two parent tables? An autonumber field would therefore be redundant?

 

[xenou]

Even with an autonumber PK you could create a unique index on the two fields that are the foreign keys to the two parent tables. It will work pretty much the same. I've done it both ways (used the composite PK and used an autonumber PK with a unique index on the two fields needed for the junction table to work).

 

[jackd]

As xenou says either way will work. I've used both. The unique composite index will prevent duplicates. If you have tables that relate to the junction table, then the autonumber on the junction is probably easier to work with.
Good luck with your project.