Help with decode

Question

Let's call the field "xfieldx". It’s currently a char data type that either gets inputted as null or “y” meaning yes. The problem comes when the query counts the number of rows that have a non-null value. The sql is below
sum(decode(xfieldx, null, 0, 'n', 0, 1)) as xfieldxCount
still returns a char value and later, when subject to a numeric condition “>” it fails. I need to make sure that this count is occurring correctly. Any wisdom?

Answer 1

Welcome to the forum!
Whenever you have a question, please post a little sample data (CREATE TABLE and INSERT statements), and the results you have from that data, so that the people who want to help you can re-create the problem and test their ideas.
If you have an existing query, post the complete query, point out where it's getting the wrong results, and explain how you'd get the right results in those places.
Always say which version of Oracle you're uisng.
Since this is your first post, I'll do some sample data for you:
CREATE TABLE     table_x
(       x_id     NUMBER (4)     PRIMARY KEY
,     xfieldx     VARCHAR2 (1)
INSERT INTO table_x (x_id, xfieldx) VALUES (0, NULL);
INSERT INTO table_x (x_id, xfieldx) VALUES (1, 'n');
INSERT INTO table_x (x_id, xfieldx) VALUES (2, 'y');
INSERT INTO table_x (x_id, xfieldx) VALUES (3, 'n');
894540 wrote:Let's call the field "xfieldx". It’s currently a char data type that either gets inputted as null or “y” meaning yes. The problem comes when the query counts the number of rows that have a non-null value. The sql is below
sum(decode(xfieldx, null, 0, 'n', 0, 1)) as xfieldxCount
still returns a char value and later, when subject to a numeric condition “>” it fails. I need to make sure that this count is occurring correctly. Any wisdom?That DECODE doesn't return a CHAR; it returs a NUMBER, either 0 or 1. (You can't use SUM on a CHAR expression.) And it's guaranteed either 0 or 1, never NULL. If you're interested in how many of the rows have a non-NULL value, just use COUNT.
The following query shows the difference:
SELECT  SUM ( DECODE ( xfieldx
                     , NULL     , 0
               , 'n'     , 0
                           , 1
         )               AS total_y
,       COUNT (xfieldx)          AS count_xfieldx
FROM     table_x
;Output:
`  TOTAL_Y COUNT_XFIELDX
         1             3This should work in any version of Oracle.
What results are you trying to get?
What are you trying to do with a > condition?