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Re: Query help

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Richard Huxton wrote:
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).

You'll want something like:

SELECT
    sch_id, sch_for_table, sch_ref_id,
    SUM(sch_instances) AS tot_instances
...
GROUP BY
    sch_id, sch_for_table, sch_ref_id
ORDER BY
    tot_instances DESC;

The key word to search the manuals on is "aggregates" (sum(), count() etc).


This is *exactly* the pointer I needed, thank you!

Sad thing is that I even used "GROUP BY" before... had just forgotten about it. ^_^;

Madison


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