Re: Query help

From: Shaun Johnston <shaunj(at)benon(dot)com>
To: Madison Kelly <linux(at)alteeve(dot)com>
Cc: pgsql-general(at)postgresql(dot)org
Subject: Re: Query help
Date: 2007-03-08 06:46:07
Message-ID: 45EFB12F.9000001@benon.com
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Try

SELECT DISTINCT

rather than SELECT

That should return a result with unique records.

Madison Kelly wrote:
> Hi all,
>
> I've got a query that looks through a table I use for my little
> search engine. It's something of a reverse-index but not quite, where
> a proper reverse index would have 'word | doc1, doc3, doc4, doc7'
> showing all the docs the keyword is in, mine has an entry for eac
>
> I've got a query like:
>
> SELECT
> sch_id, sch_for_table, sch_ref_id, sch_instances
> FROM
> search_index
> WHERE
> (sch_keyword LIKE '%digi%' OR sch_keyword LIKE '%madi%')
> AND
> sch_for_table!='client'
> AND
> ... (more restrictions)
> ORDER BY
> sch_instances DESC;
>
> This returns references to a data column (sch_ref_id) in a given
> table (sch_for_table) for each matched keyword.
>
> The problem I am having is that two keywords might reference the
> same table/column which would, in turn, give me two+ search results
> pointing to the same entry.
>
> What I would like to do is, when two or more results match the same
> 'sch_ref_id' and 'sch_for_table' to merge the results. Specifically,
> the 'sch_instances' column is the number of times the given keyword is
> found in the table/column. I'd like to add up the number in the
> duplicate results (to give it a higher accuracy and move it up the
> search results).
>
> Is this possible or would I need to add this logic in my program?
> I'd rather do it in PostgreSQL though, if I could.
>
> Here is the 'search_index' table I am using:
>
> db=> \d search_index
> Table "public.search_index"
> Column | Type | Modifiers
> ---------------+---------+-----------------------------------------------
> sch_id | integer | not null default nextval('sch_seq'::regclass)
> sch_keyword | text | not null
> sch_instances | integer | not null default 1
> sch_for_table | text | not null
> sch_ref_id | integer | not null
> Indexes:
> "search_index_pkey" PRIMARY KEY, btree (sch_id)
>
> Thanks in advance to any help you might be able to give me!
>
> Madison
>
> ---------------------------(end of broadcast)---------------------------
> TIP 5: don't forget to increase your free space map settings

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  • Query help at 2007-03-08 06:20:10 from Madison Kelly

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