Insert into cursor one at a time

Question

Hello,
Is it possible to insert one value per cycle execution on a cursor? For example:
c_anuncios cursor_anuncios;
c_result my_result_cursor;
BEGIN
     LOOP
          EXIT WHEN(c_anunciantes%NOTFOUND);
--get one comparison value
          FETCH c_anunciantes INTO idAnunciante;          
          SELECT * FROM anuncio a
          --INTO where? how do I record this single value on c_result
          WHERE a.anunciante=id_anunciante;
     END LOOP;
RETURN c_result;
There's no way (that I can think of) that I can do "OPEN c_result FOR SELECT"... because I always need to do as many queries as I have elements on the "c_anunciantes" cursor, correct?
Thanks in advance! :)

Answer 1

If I understand correctly, you want to gather 5 id numbers in a cursor and then open a cursor using each of those 5 keys and then have access to all of the rows returned by the 5 cursors in the same structure.
Will this version of your query compile?
OPEN c_anuncios FOR
SELECT *
FROM anuncio a3
WHERE anunciante IN (SELECT a1.id
FROM anunciante a1, anuncio a2
WHERE a2.anunciante = a1.id
AND a2.palavra_chave = 3
AND rownum < 6
HAVING COUNT(a1.id) > 0
ORDER BY COUNT(a1.id) DESC, SUM(a2.preco) DESC, a1.id ASC
GROUP BY a1.id)
ORDER BY a3.preco DESC, a3.num_cliques DESC, a3.id ASC;
Perhaps the following example would satisfy your requirement. It is certainly not strictly set based but bulk binding will reduce the number of context switches required to run the PL/SQL.
DECLARE
-- this procedure will loop through a set of keys to open a set of cursors
-- and store all rows from those cursors in a collection
-- the final set of records can be referenced individually by subscript 1..n
TYPE five_row_typ IS VARRAY(5) OF anunciante.id%TYPE;
five_rows five_row_typ; -- to store the 5 keys to intermediate datasets
TYPE anuncio_tbl_typ IS TABLE OF anuncio%ROWTYPE;
anuncio_tbl anuncio_tbl_typ;
-- to store the intermediate result set for each of the 5 rows
total_anuncio_tbl := anuncio_tbl_typ(); -- initialize an empty collection
--to hold result sets from each of the 5 queries
CURSOR anunciante_cur(p_chave anunciante.id%TYPE, p_rows NUMBER) IS
SELECT a1.id
FROM anunciante a1, anuncio a2
WHERE a2.anunciante = a1.id
AND a2.palavra_chave = p_chave
AND rownum < p_rows + 1
GROUP BY a1.id
HAVING COUNT(a1.id) > 0
ORDER BY COUNT(a1.id) DESC, SUM(a2.preco) DESC, a1.id ASC;
CURSOR anuncio_cur(p_id anuncio.anunciante%TYPE) IS
SELECT *
FROM anuncio a3
WHERE anunciante = p_id
ORDER BY a3.preco DESC, a3.num_cliques DESC, a3.id ASC;
k NUMBER := 0;
BEGIN
OPEN anunciante_cur(3, 5);
FETCH anunciante_cur BULK COLLECT
INTO five_rows; -- this will get all keys for cursors that follow
CLOSE anunciante_cur;
IF five_rows.EXISTS(1)
THEN
FOR i IN five_rows.FIRST .. five_rows.LAST
LOOP
OPEN anuncio_cur(five_rows(i));-- cursor will be opened p_rows times
LOOP
FETCH anuncio_cur BULK COLLECT
INTO anuncio_tbl;-- this will get all rows from a single cursor in one pass
-- each of the 5 intemediate result sets will pass through this collection
IF anuncio_tbl.EXISTS(1)
THEN
FOR j IN anuncio_tbl.FIRST .. anuncio_tbl.LAST
LOOP
k := k + 1;
total_anuncio_tbl.EXTEND;
total_anuncio_tbl(k) := anuncio_tbl(i);
-- and each element (row) of each of the 5 result sets will end here
-- whether there is one or many rows in each set
END LOOP;
END IF;
EXIT WHEN anuncio_cur%NOTFOUND OR anuncio_cur%NOTFOUND IS NULL;
END LOOP;
CLOSE anuncio_cur;
END LOOP;
END IF;
END;
Regards,
Peter