Re: Search for lists - Mailing list pgsql-general

From David Johnston
Subject Re: Search for lists
Date
Msg-id 347678D0-92D2-46C9-942D-27651A72D57B@yahoo.com
Whole thread Raw
In response to Search for lists  (Daron Ryan <daron.ryan@gmail.com>)
List pgsql-general
Untested approach
Use array_agg on column 2 along with group by on column 1 to build check arrays and then use equals to compare with an
arrayof your desired input values. 

You should omit duplicates and order ascending both the data and the input to ensure you are matching canonical forms.

David J.


On Jun 18, 2011, at 17:51, Daron Ryan <daron.ryan@gmail.com> wrote:

> Hello,
>
> I need to search a table to find sets of rows that have a column matching itself for the whole set and another column
matchingrow for row with a list I am going to supply. The result I should receive should be value of the column that
matchesitself. 
>
> For example given the following data in my table:
>
> 3;         1
> 3;         2
> 4;         8
> 4;         9
> 4;         10
>
> I might need to search for 1,2. This should produce the result 3. Or if I were to search for 8, 9, 10 the result
shouldbe 4. Searching for 8, 9 should produce an empty result as should 8, 9, 10, 11. 
>
> Can anyone recommend a strategy?
>
> --
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