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-- Returns a string consisting of the last N words. Words are allowed
-- to be seperated only by spaces, but multiple spaces between
-- words are allowed. Words must be alphanumberic.
-- If more words are requested than exist, the full input string is
-- returned.
CREATE OR REPLACE FUNCTION get_last_words(
inputString VARCHAR,
count INTEGER
) RETURNS VARCHAR
AS $_$
DECLARE
tempString VARCHAR;
result VARCHAR := '';
BEGIN
FOR i IN 1..count LOOP
tempString := substring(inputString from '((?: )+[a-zA-Z0-9_]*)' || result || '$');
IF tempString IS NULL THEN
RETURN inputString;
END IF;
result := tempString || result;
END LOOP;
result := trim(both from result);
RETURN result;
END;
$_$ LANGUAGE plpgsql IMMUTABLE COST 10;
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