Postgres Function returning no results but when the same query returns results outside function - postgresql

Question

I am running a simple postgres function to return the count of rows. I am able to run the same query outside function with the output of raise option , but the function doesn't return any rows. I have tried different ways to produce results but unable to. Please find my function below,
CREATE OR REPLACE FUNCTION my_schema.usp_spellcheck3(SearchORItems_WithPipe varchar, site varchar, lan varchar, rows_display integer)
RETURNS TABLE (docmnt int) AS $BODY$
DECLARE
arrSearchTerms text[];
NewTerm varchar;
i integer;
AltSearch_withComma varchar;
AltSearch_withPipe varchar;
strDidYouMean varchar;
dpDidYouMean double precision;
txtDidYouMean Text;
SearchORItems_withComma varchar;
SearchORItems varchar;
SearchORItem varchar;
ws varchar;
arrSearchORItems_withComma varchar[];
BEGIN
strDidYouMean = 'DidYouMeanRow';
dpDidYouMean = 0.0;
txtDidYouMean = 'DidYouMeanRow';
ws = '''' || '%' || site || '%' || '''' ;
RAISE NOTICE '%', ws;
SearchORItems = REPLACE(SearchORItems_WithPipe, '|', ',');
SELECT regexp_split_to_array(SearchORItems, ',') INTO arrSearchORItems_withComma;
RAISE NOTICE '%', SearchORItems;
FOR i IN 1 .. coalesce(array_upper(arrSearchORItems_withComma, 1), 1) LOOP
IF (i = 1) THEN
SearchORItems_withComma = '''' || arrSearchORItems_withComma[i] || '''';
ELSE
SearchORItems_withComma = SearchORItems_withComma||','||'''' || arrSearchORItems_withComma[i] || '''';
END IF;
END LOOP;
RAISE NOTICE '%',SearchORItems_withComma;
SELECT COUNT(*) INTO res_count
FROM (
SELECT 1 FROM my_schema.features f , my_schema.documents d
WHERE term IN (SearchORItems_withComma)
AND d.docid = f.docid
AND d.url LIKE ws
GROUP BY f.docid, d.url) t;
RAISE NOTICE '%', res_count;
SearchORItem = 'SELECT COUNT(*) INTO res_count
FROM (SELECT 1 FROM my_schema.features f , my_schema.documents d
WHERE term IN ('||SearchORItems_withComma||')
AND d.docid = f.docid AND d.url LIKE ' || ws ||'
GROUP BY f.docid, d.url) t';
RAISE NOTICE '%',SearchORItem;
END;
$BODY$ LANGUAGE SQL VOLATILE;
this is my query output :
NOTICE: '%uni%'
NOTICE: daniel,data
NOTICE: 'daniel','data'
NOTICE: 0
NOTICE: select count(*) into res_count
from ( select 1 from my_schema.features f , my_schema.documents d
where term in ('daniel','data')
and d.docid=f.docid and d.url like '%uni%'
group by f.docid,d.url)t
Total query runtime: 16 ms.
0 rows retrieved.
I dont know where I'm going wrong, any help would be appreciated .. Thanks..

Answer 1

The simple reason that nothing is returned is that you have no RETURN statements in your code. When a function RETURNS TABLE you need to explicitly put one or more RETURN NEXT or RETURN QUERY statements in the body of your code, with a final RETURN statement to indicate the end of the function. See the documentation here: http://www.postgresql.org/docs/9.3/static/plpgsql-control-structures.html#PLPGSQL-STATEMENTS-RETURNING. What exactly you want to return is not clear but likely candidates are res_count and d.docid.
Other than that, your code could use a real clean-up reducing clutter like:
ws := '''%' || site || '%''' ;
instead of:
ws = '''' || '%' || site || '%' || '''' ;
and:
SELECT COUNT(*) INTO res_count
FROM my_schema.features f,
JOIN my_schema.documents d ON d.docid = f.docid
WHERE term IN (SearchORItems_withComma)
AND d.url LIKE ws
GROUP BY f.docid, d.url;
instead of:
SELECT COUNT(*) INTO res_count
FROM (
SELECT 1 FROM my_schema.features f , my_schema.documents d
WHERE term IN (SearchORItems_withComma)
AND d.docid = f.docid
AND d.url LIKE ws
GROUP BY f.docid, d.url) t;
And you should use the assignment operator (:=) instead of the equality operator in any plpgsql statement that is not a SQL statement.