Adding Records at Start

[Cindy Brown]

Hi Ruslan,

I don't think in this case the structure is bad, it is just that Mark wants
to order it in a certain way which makes it a little more difficult. I could
have a student database with a number of students in similar families with
the same last name which would mean there would be duplicates, but I
wouldn't then create a second database to just hold the last names. It would
definitely be overkill and a lot harder to work with. In my case, DISTINCT
would probably work because I would order in last name order which would be
fine. In Mark's case, he wants a different order to alphabetical so he needs
to set up a separate order system. The database structure itself looks fine,
at least to me.

All the best.

Cindy

> But Mark,
> 
> I want want you that you have NOT GOOD db structure!
> 
> As you see YOU HAVE DUPLICATES.
> This is EXACT SIGN that you have bad design yet.
> 
> You can wish to split data into several tables,
> Or may be use Table with self - recursion because in your task you can have
> any number of levels.
> 
> In IDEAL, you must not have DUPLICATE data.
> 
> Think about this.
> You can read in any RDBMS book rules of table normalization.


-- 

Cindy Brown
Programmer
SchoolMaster

Kowhai Programming Systems
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