Decode or case in where

Question

i have a problem in decode clause
i have 2 conditions in my code
--condition 1
-- this condition in where clause
where  gl.attribute1 is null
and gl.attribute2 is null
-- condition 2
--another condition in where clause is
where gl.attribute1 is not null
and gl.attribute2 is not nulli have a parameter is :p_exception = yes then condition 1 runs otherwise condition 2 runs
please help

Answer 1

Checkout:
SQL> SELECT * FROM t;
         A          B
         1
                    5
         4          5
SQL>  variable p_exception varchar2(3);
SQL> exec :p_exception :='Yes';
PL/SQL procedure successfully completed.
SQL>  SELECT * FROM t WHERE (:p_exception = 'Yes' AND a IS NULL AND b IS NULL) OR (:p_exception='No' AND a IS NOT NULL AND b IS NOT NULL);
         A          B
SQL> exec :p_exception :='No';
PL/SQL procedure successfully completed.
SQL> ed
Wrote file afiedt.buf
  1*  SELECT * FROM t WHERE (:p_exception = 'Yes' AND a IS NULL AND b IS NULL) OR (:p_exception='No' AND a IS NOT NULL AND b IS NOT NULL)
SQL>
SQL> /
         A          B
         4          5