Re: Trouble with text search select statement

[Klint Gore <kgore4(at)une(dot)edu(dot)au>]

Mont Rothstein wrote:
> I am having trouble getting a multiple column text search select 
> statement to work.
>
> I've setup the following:
>
> CREATE TABLE tstest (col1 text, col2 text);
> INSERT INTO tstest (col1, col2) VALUES ('bird', 'moon');
> CREATE INDEX tstest_ts_idx ON tstest USING gin(to_tsvector('english', 
> coalesce(col1, '') || '' || coalesce(col2, '')));
>
> I then execute what I believe is the correct select statement:
>
> SELECT * FROM tstest WHERE to_tsvector('english', coalesce(col1, '') 
> || '' || coalesce(col2, '')) @@ to_tsquery('english', 'bird');
>
> If I remove the second column from the to_tsvector in the select 
> statement then it returns the row.
>
> SELECT * FROM tstest WHERE to_tsvector('english', coalesce(col1, '')) 
> @@ to_tsquery('english', 'bird');
>
> I know I've missed something basic but I can't figure out what.
>
> As a side note I don't understand the purpose of the || '' || between 
> the columns in the to_tsvector.  I saw it in several examples.  I've 
> tried both with and without it with no change.
'' isn't supposed to to be the empty string, it's supposed to be a 
quoted space.  to_tsvector separates on whitespace. So with the space, 
it will have the words bird and moon.Without the space, it will have the 
single word birdmoon.

klint.

--
Klint Gore
Database Manager
Sheep CRC
A.G.B.U.
University of New England
Armidale NSW 2350

Ph: 02 6773 3789  
Fax: 02 6773 3266
EMail: kgore4(at)une(dot)edu(dot)au