Re: Qryout file problem -- MIDRANGE-L

Not to be reminiscent of the Dilbert cartoon in which Saint Dogbert banishes 
the fellow spouting useless database concepts by showing him actual code but 
here goes.

Database normalization has many levels and I am not sure on each of them.  Many 
of the bad databases I've seen recently come from the PC world.  Microsoft 
Access and (using database loosely) any spreadsheet.  Sample database, using a 
bill of material example, would look like:
Masterpart      child1  child2  child3  child4  etc...
XYZ             A       B       C
TWO             C       B       D
THREE           A       C       D       E

Now the problem is when you try to find out all the parts containing C.  
Querying these kind of databases is grunt work.  To avoid this problem we would 
normalize the database into two databases.  The master, containing all 
information about all parts, both master and children.  And then a 
bill-of-material database informing you of what children are on which part.  
The b-o-m database would look like the following:
Master part     child
XYZ             A
XYZ             B
XYZ             C
TWO             C
TWO             B
TWO             D
THREE           A
THREE           C
THREE           D
THREE           E
And then you could do:  SELECT MASTERPART FROM BOM WHERE CHILD='C'
This would tell you what parts contain 'C'.






John.Taylor@britax-pmg.com on 04/28/99 10:40:19 AM
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Subject:        Re: Qryout file problem

Rob

>No problem, write an RPG program to 'denormalize' your database.

I did'nt in fact realise we had a normal database. Anyway I'm not a
programmer so I must follow the query route.

Thanks 

John

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<P><FONT SIZE=2>Rob</FONT>
</P>

<P><FONT SIZE=2>&gt;No problem, write an RPG program to 'denormalize' your 
database.</FONT>
</P>

<P><FONT SIZE=2>I did'nt in fact realise we had a normal database. Anyway I'm 
not a programmer so I must follow the query route.</FONT>
</P>

<P><FONT SIZE=2>Thanks </FONT>
</P>

<P><FONT SIZE=2>John</FONT>
</P>

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