Re: RETURNS TABLE function: ERROR: column reference "word" is ambiguous

2016-08-10 15:18 GMT+02:00 Charles Clavadetscher <clavadetscher(at)swisspug(dot)org
>:

> Hello
>
> > -----Original Message-----
> > From: pgsql-general-owner(at)postgresql(dot)org [mailto:pgsql-general-owner@
> postgresql.org] On Behalf Of Alexander Farber
> > Sent: Mittwoch, 10. August 2016 14:54
> > To: pgsql-general <pgsql-general(at)postgresql(dot)org>
> > Subject: [GENERAL] RETURNS TABLE function: ERROR: column reference
> "word" is ambiguous
> >
> > Good afternoon,
> >
> >
> > In PostgreSQL 9.5.3 I have created a function (full source code at the
> bottom), which goes through an 15 x 15
> > varchar array and collects words played horizontally and vertically.
> >
> >
> > I have declared the function as:
> >
> >
> > CREATE OR REPLACE FUNCTION words_check_words(
> > IN in_uid integer,
> > IN in_gid integer,
> > IN in_tiles jsonb)
> > RETURNS TABLE(word varchar, score integer) AS $func$
> ................
> > CREATE TEMPORARY TABLE _words (word varchar, score integer) ON
> COMMIT DROP; ...............
> > SELECT word, max(score) as score FROM _words GROUP BY word; END
> $func$ LANGUAGE plpgsql;
> >
> >
> > And when I call it as:
> >
> >
> > select * from words_check_words(2, 1,
> > '[{"col":11,"letter":"A","row":8,"value":1},{"col":11,"
> letter":"B","row":7,"value":3}]'::jsonb);
> >
> >
> > then it fails with:
> >
> >
> > ERROR: column reference "word" is ambiguous LINE 1: SELECT word,
> max(score) as score FROM _words GROUP BY word
> > ^
> > DETAIL: It could refer to either a PL/pgSQL variable or a table column.
> >
> >
> > As I understand the "word" is used both by the RETURN TYPE and my TEMP
> TABLE.
> >
> >
> > How to resolve this "naming conflict" best or maybe there is some better
> way like using some "internal" table
> > implicitly created by the type declaration?
> >
> >
> > Thank you
> >
> > Alex
> >
> >
> > P.S. Below is my full source code and the full log output -
> >
> >
>
> You can use
>
> #variable_conflict [use_column|use_variable] before BEGIN:
>
> - http://dba.stackexchange.com/questions/105831/naming-
> conflict-between-function-parameter-and-result-of-join-with-using-clause
> - https://www.postgresql.org/docs/current/static/plpgsql-
> implementation.html
>
>
I am sorry, but disabling this check is not good.This is pretty big trap.

correct and usual solution is using qualified names

_words.word

Regards

Pavel

> Hope this helps.
> Regards
> Charles
>
> > CREATE OR REPLACE FUNCTION words_check_words(
> > IN in_uid integer,
> > IN in_gid integer,
> > IN in_tiles jsonb)
> > RETURNS TABLE(word varchar, score integer) AS $func$ DECLARE
> > _tile jsonb;
> > _letter varchar;
> > _letter2 varchar;
> > _value integer;
> > _value2 integer;
> > _col integer;
> > _col2 integer;
> > _row integer;
> > _row2 integer;
> > _letters varchar[][];
> > _values integer[][];
> > _mult varchar[][];
> > _factor integer;
> > _score integer;
> > _word varchar;
> > BEGIN
> > SELECT
> > g.letters,
> > g.values,
> > b.mult
> > INTO
> > _letters,
> > _values,
> > _mult
> > FROM words_games g, words_boards b WHERE
> > g.gid = in_gid AND
> > g.bid = b.bid AND
> > g.player1 = in_uid AND
> > -- and it is first player's turn
> > (g.played1 IS NULL OR g.played1 < g.played2);
> >
> > IF NOT FOUND THEN
> > SELECT
> > g.letters,
> > g.values,
> > b.mult
> > INTO
> > _letters,
> > _values,
> > _mult
> > FROM words_games g, words_boards b WHERE
> > g.gid = in_gid AND
> > g.bid = b.bid AND
> > g.player2 = in_uid AND
> > -- and it is first player's turn
> > (g.played2 IS NULL OR g.played2 < g.played1);
> > END IF;
> >
> > IF NOT FOUND THEN
> > RAISE EXCEPTION 'Game % not found for user %', in_gid,
> in_uid;
> > END IF;
> >
> > CREATE TEMPORARY TABLE _words (word varchar, score integer) ON
> COMMIT DROP;
> >
> > FOR _tile IN SELECT * FROM JSONB_ARRAY_ELEMENTS(in_tiles)
> > LOOP
> > _letter := _tile->>'letter';
> > _value := (_tile->>'value')::int;
> > _col := (_tile->>'col')::int + 1;
> > _row := (_tile->>'row')::int + 1;
> >
> > _letters[_col][_row] := _letter;
> > -- multiply the new letter value with premium
> > _values[_col][_row] := _value *
> words_letter_mult(_mult[_col][_row]);
> >
> > _word := _letter;
> > _score := _values[_col][_row];
> > _factor := words_word_mult(_mult[_col][_row]);
> >
> > -- go left and prepend letters
> > FOR _col2 IN REVERSE (_col - 1)..1 LOOP
> > _letter2 := _letters[_col2][_row];
> > EXIT WHEN _letter2 IS NULL;
> > _value2 := _values[_col2][_row];
> > _word := _letter2 || _word;
> > _score := _score + _value2;
> > _factor := _factor *
> words_word_mult(_mult[_col2][_row]);
> > END LOOP;
> >
> > -- go right and append letters
> > FOR _col2 IN (_col + 1)..15 LOOP
> > _letter2 := _letters[_col2][_row];
> > EXIT WHEN _letter2 IS NULL;
> > _value2 := _values[_col2][_row];
> > _word := _word || _letter2;
> > _score := _score + _value2;
> > _factor := _factor *
> words_word_mult(_mult[_col2][_row]);
> > END LOOP;
> >
> > IF LENGTH(_word) > 1 /* AND EXISTS SELECT 1 FROM
> words_nouns */ THEN
> > INSERT INTO _words(word, score)
> > VALUES (upper(_word), _score);
> > END IF;
> >
> > _word := _letter;
> > _score := _values[_col][_row];
> > _factor := words_word_mult(_mult[_col][_row]);
> >
> > -- go up and prepend letters
> > FOR _row2 IN REVERSE (_row - 1)..1 LOOP
> > _letter2 := _letters[_col][_row2];
> > EXIT WHEN _letter2 IS NULL;
> > _value2 := _values[_col][_row2];
> > _word := _letter2 || _word;
> > _score := _score + _value2;
> > _factor := _factor *
> words_word_mult(_mult[_col][_row2]);
> > END LOOP;
> >
> > -- go down and append letters
> > FOR _row2 IN (_row + 1)..15 LOOP
> > _letter2 := _letters[_col][_row2];
> > EXIT WHEN _letter2 IS NULL;
> > _value2 := _values[_col][_row2];
> > _word := _word || _letter2;
> > _score := _score + _value2;
> > _factor := _factor *
> words_word_mult(_mult[_col][_row2]);
> > END LOOP;
> >
> > IF LENGTH(_word) > 1 /* AND EXISTS SELECT 1 FROM
> words_nouns */ THEN
> > INSERT INTO _words(word, score)
> > VALUES (upper(_word), _score);
> > END IF;
> > END LOOP;
> >
> > RAISE NOTICE 'letters = %', _letters;
> > RAISE NOTICE 'values = %', _values;
> > RAISE NOTICE 'mult = %', _mult;
> >
> > SELECT word, max(score) as score FROM _words GROUP BY word; END
> $func$ LANGUAGE plpgsql;
> >
> >
> > -----------------
> >
> >
> > -- apologies for non-english letters here
> >
> >
> > LOG: statement: select * from words_check_words(2, 1,
> > '[{"col":11,"letter":"?","row":8,"value":1},{"col":11,"
> letter":"?","row":7,"value":3}]'::jsonb);
> > NOTICE: letters =
> > {{NULL,NULL,NULL,NULL,NULL,NULL,NULL,NULL,NULL,NULL,NULL,
> NULL,NULL,NULL,NULL},{NULL,NULL,NULL,NULL,NULL,NULL,NULL,NU
> > LL,NULL,NULL,NULL,NULL,NULL,NULL,NULL},{NULL
> > ,NULL,NULL,NULL,NULL,NULL,NULL,NULL,NULL,NULL,NULL,NULL,
> NULL,NULL,NULL},{NULL,NULL,NULL,NULL,NULL,NULL,NULL,NULL,NUL
> > L,NULL,NULL,NULL,NULL,NULL,NULL},{NULL,NULL,NULL,NULL,NULL,NULL,
> > NULL,NULL,NULL,NULL,NULL,NULL,NULL,NULL,NULL},{NULL,NULL,
> NULL,NULL,NULL,NULL,NULL,NULL,NULL,NULL,NULL,NULL,NULL,NULL
> > ,NULL},{NULL,NULL,NULL,NULL,NULL,NULL,NULL,NULL,NULL,М,NULL,NULL
> > ,NULL,NULL,NULL},{NULL,NULL,NULL,NULL,NULL,NULL,NULL,Э,Р,
> О,Е,NULL,NULL,NULL,NULL},{NULL,NULL,NULL,NULL,NULL,NULL,NUL
> > L,NULL,NULL,Х,NULL,NULL,NULL,NULL,NULL},{NULL,NULL,NULL,NULL,NUL
> > L,NULL,NULL,NULL,NULL,И,NULL,NULL,NULL,NULL,NULL},{NULL,
> NULL,NULL,NULL,NULL,NULL,NULL,NULL,NULL,В,NULL,NULL,NULL,NUL
> > L,NULL},{NULL,NULL,NULL,NULL,NULL,NULL,NULL,?,?,Ы,NULL,NULL,NULL
> > ,NULL,NULL},{NULL,NULL,NULL,NULL,NULL,NULL,NULL,NULL,NULL,
> NULL,NULL,NULL,NULL,NULL,NULL},{NULL,NULL,NULL,NULL,NULL,N
> > ULL,NULL,NULL,NULL,NULL,NULL,NULL,NULL,NULL,NULL},{NULL,NULL,NUL
> > L,NULL,NULL,NULL,NULL,NULL,NULL,NULL,NULL,NULL,NULL,NULL,NULL}}
> > NOTICE: values =
> > {{NULL,NULL,NULL,NULL,NULL,NULL,NULL,NULL,NULL,NULL,NULL,
> NULL,NULL,NULL,NULL},{NULL,NULL,NULL,NULL,NULL,NULL,NULL,NU
> > LL,NULL,NULL,NULL,NULL,NULL,NULL,NULL},{NULL
> > ,NULL,NULL,NULL,NULL,NULL,NULL,NULL,NULL,NULL,NULL,NULL,
> NULL,NULL,NULL},{NULL,NULL,NULL,NULL,NULL,NULL,NULL,NULL,NUL
> > L,NULL,NULL,NULL,NULL,NULL,NULL},{NULL,NULL,NULL,NULL,NULL,NULL,
> > NULL,NULL,NULL,NULL,NULL,NULL,NULL,NULL,NULL},{NULL,NULL,
> NULL,NULL,NULL,NULL,NULL,NULL,NULL,NULL,NULL,NULL,NULL,NULL
> > ,NULL},{NULL,NULL,NULL,NULL,NULL,NULL,NULL,NULL,NULL,2,NULL,NULL
> > ,NULL,NULL,NULL},{NULL,NULL,NULL,NULL,NULL,NULL,NULL,10,2,
> 1,1,NULL,NULL,NULL,NULL},{NULL,NULL,NULL,NULL,NULL,NULL,NU
> > LL,NULL,NULL,5,NULL,NULL,NULL,NULL,NULL},{NULL,NULL,NULL,NULL,NU
> > LL,NULL,NULL,NULL,NULL,1,NULL,NULL,NULL,NULL,NULL},{NULL,
> NULL,NULL,NULL,NULL,NULL,NULL,NULL,NULL,2,NULL,NULL,NULL,NU
> > LL,NULL},{NULL,NULL,NULL,NULL,NULL,NULL,NULL,6,1,5,NULL,NULL,NUL
> > L,NULL,NULL},{NULL,NULL,NULL,NULL,NULL,NULL,NULL,NULL,NULL,
> NULL,NULL,NULL,NULL,NULL,NULL},{NULL,NULL,NULL,NULL,NULL,
> > NULL,NULL,NULL,NULL,NULL,NULL,NULL,NULL,NULL,NULL},{NULL,NULL,NU
> > LL,NULL,NULL,NULL,NULL,NULL,NULL,NULL,NULL,NULL,NULL,NULL,NULL}}
> > NOTICE: mult =
> > {{TW,NULL,NULL,DL,NULL,NULL,NULL,TW,NULL,NULL,NULL,DL,
> NULL,NULL,TW},{NULL,TL,NULL,NULL,NULL,DW,NULL,NULL,NULL,DW,NUL
> > L,NULL,NULL,TL,NULL},{NULL,NULL,TL,NULL,NULL
> > ,NULL,DL,NULL,DL,NULL,NULL,NULL,TL,NULL,NULL},{DL,NULL,
> NULL,TL,NULL,NULL,NULL,DL,NULL,NULL,NULL,TL,NULL,NULL,DL},{NU
> > LL,NULL,NULL,NULL,TL,NULL,NULL,NULL,NULL,NULL,TL,NULL,NULL,NULL,
> > NULL},{NULL,DW,NULL,NULL,NULL,NULL,NULL,NULL,NULL,NULL,NULL,
> NULL,NULL,DW,NULL},{NULL,NULL,DL,NULL,NULL,NULL,DL,NULL,
> > DL,NULL,NULL,NULL,DL,NULL,NULL},{TW,NULL,NULL,DL,NULL,NULL,NULL,
> > NULL,NULL,NULL,NULL,DL,NULL,NULL,TW},{NULL,NULL,DL,NULL,
> NULL,NULL,DL,NULL,DL,NULL,NULL,NULL,DL,NULL,NULL},{NULL,DW,N
> > ULL,NULL,NULL,NULL,NULL,NULL,NULL,NULL,NULL,NULL,NULL,DW,NULL},{
> > NULL,NULL,NULL,NULL,TL,NULL,NULL,NULL,NULL,NULL,TL,NULL,
> NULL,NULL,NULL},{DL,NULL,NULL,TL,NULL,NULL,NULL,DL,NULL,NULL
> > ,NULL,TL,NULL,NULL,DL},{NULL,NULL,TL,NULL,NULL,NULL,DL,NULL,DL,N
> > ULL,NULL,NULL,TL,NULL,NULL},{NULL,TL,NULL,NULL,NULL,DW,
> NULL,NULL,NULL,DW,NULL,NULL,NULL,TL,NULL},{TW,NULL,NULL,DL,NU
> > LL,NULL,NULL,TW,NULL,NULL,NULL,DL,NULL,NULL,TW}}
> > ERROR: column reference "word" is ambiguous at character 8
> > DETAIL: It could refer to either a PL/pgSQL variable or a table column.
> > QUERY: SELECT word, max(score) as score FROM _words GROUP BY word
> > CONTEXT: PL/pgSQL function words_check_words(integer,integer,jsonb)
> line 131 at SQL statement
> > STATEMENT: select * from words_check_words(2, 1,
> > '[{"col":11,"letter":"?","row":8,"value":1},{"col":11,"
> letter":"?","row":7,"value":3}]'::jsonb);
> >
> >
>
>
>
>
> --
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