Re: Database Design Best Practice help

From: orcl <orcl_at_comcast.net>
Date: Thu, 31 Jan 2013 17:46:21 -0500
Message-ID: <510AF43D.5020608_at_comcast.net>



Elementary explanation...

What you're showing there are library tables. (specie, movement,diseaselib)differentiatedby thedescriptionof the LIBRARY, which is one reason youdon’twant this in one table. At the least you would add a unique primary key system generated IDcolumn. That would become the foreignkey for the row/value in other tables and for joined queries

i.e.

SPECIE_LIB SYS_GEN_ID CODE DESCRIPTION/SPECIE
8735688 0801 Poultry

You would then reference either the CODE or the DESCRIPTION/SPECIE as the SYS_GEN_ID as foreignkeys in other tables orqueries. This will also provide functionality tochangethecode or description/specie throughout the database as it always referencesthelibrary table SYS_GEN_ID for look up (not the actual values). The SYS_GEN_ID does NOT ever change.

Just my 2cts
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Received on Thu Jan 31 2013 - 23:46:21 CET

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