Re: HELP with data model
Date: 1996/01/04
Message-ID: <4cfacg$2a8_at_kettle.magna.com.au>#1/1
> one1000eye_at_aol.com (One1000eye) writes:
> We are in the process of developing 'Skills system'. We have a
> many-to-many recursive Skill entity. That is, Skill can consist of set of
> skills, which ,in turn, can have many components. For example:
> PROGRAMMING is a skill and further classifications are C, C++, FORTRAN,
> SQL etc. SQL can belong to ORACLE, SYBASE etc.
>
> I am sure some of you might have figured this out and found a suitable
> relational representation. This is very simillar to Bill of Materials
> problem. Can any one share his/her experience? All suggestions are
> welcome. Thanks in advance.
>
> Alagu Kannayiram
>
>>>>
You need two tables. One is a skills table and the other is a skills
relationship table.
In the example you have given, it looks like a one to many but say there is a skill called TESTING which has further classifications of C, C++, Oracle then you can have
Table: SKILL
SKILL
C
C++
Programming
Testing
ORACLE Table: SKILL_REL
PARENT CHILD
------- --------
Prog C Prog C++ Prog Oracle
Testing C
Testing C++
Testing Oracle
A many to many relationship like A >---< B can be resovled by having an intermediate entity C so that A ---< C >---- B. In this case the many to many is A >---< A. This can be resolved to A ----< B >---- A.
Regards
Prashant Received on Thu Jan 04 1996 - 00:00:00 CET