Here's an example.  Suppose you have a table "UsedCars" that looks like:

Color  Make    Age
-------------------
Green  Saturn  New
Green  Saturn  Old
Red    Saturn  New
Purple Toyota  New
Purple Toyota  Old
Blue   Yugo    Ancient

The users searches on "Make", and the returned data to the user is a 
combination of Color and Make.  The user just wants to see the unique 
values, i.e.

Green Saturn
Red Saturn
Purple Toyota
Blue Yugo

(or whichever of those match the query).  I could get rid of the 
duplicates (e.g. the two Green Saturns) after doing the query, but the 
table is large, has a lot of duplicates, and I'm limiting size of the 
return list, so if I get rid of duplicates then I may need to make a 
second query to get more if it turns out that after getting rid of the 
duplicates my list is too short.  (Potentially, I could be left with 
just one item to show.)

In SQL, I could get the list like:
   select distinct Color, Make from UsedCars limit 15

Is there a good way of doing that in ferret?  If not, would writing a 
filter be a good approach?

Thanks,
    --Paul


Benjamin Krause wrote:
> On 2007-08-16, at 3:15 AM, Paul Lynch wrote:
> 
>> Is there a way in Ferret to do something akin to SQL's "SELECT  
>> DISTINCT"
>> query?  I  have a table with multiple columns, and I would like to
>> search just a couple of them (but index others for other kinds of
>> searches on the table).  The two columns I want to search do not have
>> unique values, because the other columns finish specifying the record.
>> Is there a way to avoid picking up the duplicates in the result list?
> 
> Paul,
> 
> i think i don't get your point.. If you search for something in ferret,
> you will never get duplicates in your result set (meaning ferret
> documents). However, your columns (fields in ferret terms) might
> have the same value for several documents.
> 
> So you just want to get the different field values for your search,
> but not the actual ferret documents?
> 
> Maybe you can give us a small example of your data, searches,
> actual results and what you would like to have as a result :-)
> 
> Ben

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