Re: eliminate duplicate in JOIN

From: Shakespeare <whatsin_at_xs4all.nl>
Date: Sun, 05 Apr 2009 10:40:27 +0200
Message-ID: <49d86e7d$0$196$e4fe514c_at_news.xs4all.nl>

Carl Forsman schreef:
> The following query will return Triple word from a table like the
> following:
>
> pretty, woman, a
> a, pretty woman
> china,great, wall
> wall, great, china
> great, wall, china
>
> =============================
> How can I elimate rows that contain the same words?
> The output should be:
>
> pretty, woman, a
> wall, great, china
> -OR-
> a, pretty woman
> wall, great, china
> -OR-
> a, pretty woman
> great, wall, china
>
> ... etc
>
> =============================
> The output should not have 2 row containsexact 3 words
>
> For example, if I have 3 words ( pretty + woman + a )
> pretty, woman, a
>
> Then the output will not contain (a + pretty + woman)
> a, pretty woman
>
> =============================
> SELECT DISTINCT A.word As word1, B.word AS word2, C.word AS word3
> FROM Data AS A
> JOIN Data AS B
> ON A.document = B.document
> AND A.position < B.position
> AND ABS(A.position - B.position) < 3
> JOIN Data AS C
> ON A.document = C.document
> AND A.position < C.position
> AND B.position < C.position
> AND ABS(A.position - C.position) < 3
> ORDER BY word1;
>

By only accepting sequences that are in alphabetic order, but then you may have to circumvent duplicate words.

Shakespeare Received on Sun Apr 05 2009 - 03:40:27 CDT