[Zope3-dev] Re: [Zope-DB] Relational Databases in Zope 2 and Zope 3

[Scot McSweeney-Roberts]

Charlie Clark wrote:

>On 2004-06-29 at 12:52:53 [+0200], "Smith, Neil (Worcester)" 
><Neil.Smith at npower.com> wrote:
>  
>
>>    <params>
>>    product
>>    colour
>>    size
>>    available
>>    </params>
>>    select * from products
>>    <dtml-sqlgroup where>
>>    <dtml-sqltest product type=nb optional>
>>    <dtml-and>
>>    <dtml-sqltest colour type=nb optional>
>>    <dtml-and>
>>    <dtml-sqltest size type=nb optional>
>>    <dtml-and>
>>    <dtml-sqltest available op=gt type=int optional>
>>    </dtml-sqlgroup>
>>
>>    
>>
>
>    select * from products
>	WHERE 1 = 1
>	<dtml-if product>
>	AND product =  <dtml-sqlvar product type=nb optional>
>	</dtml-if>
>	<dtml-if colour>
>    AND	colour = <dtml-sqlvar colour type=nb optional>
>    </dtml-if>
>	<dtml-if size>
>	AND size = <dtml-sqlvar size type=nb optional>
>	</dtml-if>
>    <dtml-if>
>	AND	available >  <dtml-sqlvar available type=int optional>
>    </dtml-if>
> 
>This isn't much longer has the advantage of being virtually pure SQL so 
>imminently more readable.
>  
>


I have to completly disagree, I find your code is far less readable. For 
a start, I find WHERE 1=1 to be a kludge, something I was releaved to 
find that I no longer needed with <dtml-sqlgroup where>. It also more 
long winded requireing extra closing tags and ANDs. I'm not that 
concerened Neil's code isn't as 'pure' SQL as yours (in the same way as 
I'm not concerned that my page templates aren't 'pure' HTML)  - anyone 
with a good understanding of SQL who's read the Relational Database 
section of the Zope book should be quite capable of understanding what's 
going on - even without the Zope book it's still reasonbly clear.


cheers

Scot