Craig
>How do I pull out all the non-duplicate records?
With an exclusion join. To find non-duplicates with respect to one key...
SELECT keycandidate
FROM tbl t1
LEFT JOIN tbl t2 ON t1.keycandidate=t2.keycandidate
WHERE t2.keycandidate IS NULL;
To expand the comparison to multiple keys...
SELECT key1, key2, ...
FROM tbl t1
LEFT JOIN tbl t2 ON t1.key1=t2.key2 AND t1.key2=t2.key2 AND ...
WHERE t2.key1 IS NULL;
PB
Weston, Craig (OFT) wrote:
> Hi there,
>
> I have a situation where I have duplicate data within
> several tables, but they are all indexed in the same way. How do I pull
> out all the non-duplicate records?
>
>
>
>
>
> Would I have to create a temporary table, add one data set, then add the
> second where it doesn't equal the first, and then do the same with the
> third? Or is there a cleaner way?
>
>
>
>
>
> Thanks,
>
> Craig
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