Can I use a cursor like this ...

Question

I have 10 columns that are named block_1 through block_10. I want to carry out some validation on the 10 columns but I do not want to use 10 separate conditional statements to process them. So what I would like to do is use a FOR LOOP to return a number into the variable COL_NUM, I will then use this value to numerically increment the column names from 1 to 10. Then hope to use the concatenated results which include the cursor variable to form an IF THEN statement that will be looped through. WHat I have does not work, Is this because using cursor in this way cant be done or is it for some other reason?
  OPEN get_invalid_cur;
  LOOP
    FETCH get_invalid_cur INTO p_rec;
    EXIT
  WHEN get_invalid_cur%NOTFOUND; 
  upl_id_num := p_rec.upl_id;
FOR col_num IN 1..10
  LOOP
    fk_chk_blk_id := 'p_rec.fk_chk_blk_id_' || col_num;
            block := 'p_rec.block_' || col_num;
    IF fk_chk_blk_id IS NULL AND block > 0 THEN
      p_error_desc := p_error_desc || ' (FK violated BLOCK)';
      UPDATE fmbsite.fbt_doc_bulk_upload SET error_desc = p_error_desc WHERE upl_id = p_rec.upl_id AND created_by = user;
    END IF;
  END LOOP;
  END LOOP; -- Loop for get_invalid_cur
  CLOSE get_invalid_cur;I want to do the above so that I don't have to do the following:
  OPEN get_invalid_cur;
  LOOP
    FETCH get_invalid_cur INTO p_rec;
    EXIT
  WHEN get_invalid_cur%NOTFOUND; 
  upl_id_num := p_rec.upl_id;
IF p_rec.fk_chk_blk_id_1 IS NULL AND p_rec.block_1 > 0 THEN
    p_error_desc := p_error_desc || ' (FK violated BLOCK_1)';
    UPDATE fmbsite.fbt_doc_bulk_upload SET error_desc = p_error_desc WHERE upl_id = p_rec.upl_id AND created_by = user;
  END IF;
  IF p_rec.fk_chk_blk_id_2 IS NULL AND p_rec.block_2 > 0 THEN
    p_error_desc := p_error_desc || ' (FK violated BLOCK_2)';
    UPDATE fmbsite.fbt_doc_bulk_upload SET error_desc = p_error_desc WHERE upl_id = p_rec.upl_id AND created_by = user;
  END IF;
and so on another 8 times ...
  END LOOP; -- Loop for get_invalid_cur
  CLOSE get_invalid_cur;Cheers
Benton
Edited by: Benton on Nov 22, 2010 11:59 AM

Answer 1

Benton wrote:
I have 10 columns that are named block_1 through block_10. I want to carry out some validation on the 10 columns but I do not want to use 10 separate conditional statements to process them. So what I would like to do is use a FOR LOOP to return a number into the variable COL_NUM, I will then use this value to numerically increment the column names from 1 to 10. Then hope to use the concatenated results which include the cursor variable to form an IF THEN statement that will be looped through. WHat I have does not work, Is this because using cursor in this way cant be done or is it for some other reason?
OPEN get_invalid_cur;
LOOP
FETCH get_invalid_cur INTO p_rec;
EXIT
WHEN get_invalid_cur%NOTFOUND; 
upl_id_num := p_rec.upl_id;
FOR col_num IN 1..10
LOOP
fk_chk_blk_id := 'p_rec.fk_chk_blk_id_' || col_num;
block := 'p_rec.block_' || col_num;
IF fk_chk_blk_id IS NULL AND block > 0 THEN
p_error_desc := p_error_desc || ' (FK violated BLOCK)';
UPDATE fmbsite.fbt_doc_bulk_upload SET error_desc = p_error_desc WHERE upl_id = p_rec.upl_id AND created_by = user;
END IF;
END LOOP;
END LOOP; -- Loop for get_invalid_cur
CLOSE get_invalid_cur;I want to do the above so that I don't have to do the following:
OPEN get_invalid_cur;
LOOP
FETCH get_invalid_cur INTO p_rec;
EXIT
WHEN get_invalid_cur%NOTFOUND; 
upl_id_num := p_rec.upl_id;
IF p_rec.fk_chk_blk_id_1 IS NULL AND p_rec.block_1 > 0 THEN
p_error_desc := p_error_desc || ' (FK violated BLOCK_1)';
UPDATE fmbsite.fbt_doc_bulk_upload SET error_desc = p_error_desc WHERE upl_id = p_rec.upl_id AND created_by = user;
END IF;
IF p_rec.fk_chk_blk_id_2 IS NULL AND p_rec.block_2 > 0 THEN
p_error_desc := p_error_desc || ' (FK violated BLOCK_2)';
UPDATE fmbsite.fbt_doc_bulk_upload SET error_desc = p_error_desc WHERE upl_id = p_rec.upl_id AND created_by = user;
END IF;
and so on another 8 times ...
END LOOP; -- Loop for get_invalid_cur
CLOSE get_invalid_cur;Cheers
Benton
Edited by: Benton on Nov 22, 2010 11:59 AMUse tag
Regards,
Sayan M.
ps. i'm going to lunch... will read and answer later