Re: a problem about database modeling
From: Bob Badour <bbadour_at_pei.sympatico.ca>
Date: Fri, 21 Jul 2006 01:23:42 GMT
Message-ID: <y0Wvg.13020$pu3.299367_at_ursa-nb00s0.nbnet.nb.ca>
>
> the model is simple i hava device and every device has there own
> attributes and also the device type should be one of device's
> attibute.but the point is every type has there own attributes. so i
> do't know how to modeling this.
> i need avoid NULLs and redundant both.
> thanks for any help!
Date: Fri, 21 Jul 2006 01:23:42 GMT
Message-ID: <y0Wvg.13020$pu3.299367_at_ursa-nb00s0.nbnet.nb.ca>
dxuranus wrote:
> Neo wrote:
>
>>>i list my sql code here table device: CREATE TABLE `equ` ( .... >> >>There is no simple, normalized and NULL-less solution to your problem >>with a RMDB. If you could post some actual data, I can show how dbd >>handles it and one of the RM experts can design a schema that meets >>your needs. What exactly are you needs? Are you trying to avoid NULLs >>and or redundant data or more than X number of tables?
>
> the model is simple i hava device and every device has there own
> attributes and also the device type should be one of device's
> attibute.but the point is every type has there own attributes. so i
> do't know how to modeling this.
> i need avoid NULLs and redundant both.
> thanks for any help!
What was your objection to joins again? Received on Fri Jul 21 2006 - 03:23:42 CEST