Re: extracting words

am  Tue, dem 22.04.2008, um 22:25:04 +0100 mailte Tarlika Elisabeth Schmitz folgendes:
> I am not quite sure whether this would be sensible or indeed at
> all possible to do in SQL:
> 
> TABLE product: product_pk,  product_name, department_fk
> TABLE product: department_pk,  department_name
> 
> example data:
> 
> SELECT product_pk, department_name, product_name ... LEFT JOIN ...:
> 
> 1, "cakes & desserts", "apple crumble"
> 2, "cakes & desserts", "cheese cake"
> 3, "starters & soups", "french onion soup"
> 
> 
> I need to extract the words from department_name and product_name
> (words are separated by spaces) and get something like:
> 
> 1 cakes
> 1 desserts
> 1 apple
> 1 crumble
> 2 cakes
> 2 desserts
> 2 cheese
> 2 cake
> 3 starters
> 3 soups
> 3 french
> 3 onion
> 3 soup
> 

A little function (author: David Fetter)

-- split a string to rows, by David Fetter
CREATE OR REPLACE FUNCTION split_to_rows(TEXT, TEXT) RETURNS SETOF TEXT
STRICT
LANGUAGE sql
AS $$   SELECT (string_to_array($1, $2))[s.i]   FROM generate_series(       1,       array_upper(string_to_array($1,
$2),1)   ) AS s(i);
 
$$;


And now:

test=*# select * from product ;id |       val1       |       val2
----+------------------+------------------- 1 | cakes & desserts | apple crumble 2 | cakes & desserts | cheese cake 3 |
starters& soups | french onion soup
 
(3 rows)

test=*# select id, split_to_rows(replace(val1 || ' ' || val2,' &',''),' ') as col1 from product;id |   col1
----+---------- 1 | cakes 1 | desserts 1 | apple 1 | crumble 2 | cakes 2 | desserts 2 | cheese 2 | cake 3 | starters 3
|soups 3 | french 3 | onion 3 | soup
 
(13 rows)



HTH, Andreas
-- 
Andreas Kretschmer
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