Generating a 'WHERE' clause using a function

Question

Hi I have below requirement,
for given function below are input parameters,
sk_func(salary,dept_no,job,hire_date)
which ever input is given those inputs should be there in one statement,
For example if I give input as
select sk_func(5000,null,null,null) from dual;
I need output as Where salary=5000;
if I give input as
select sk_func(5000,null,'Programmer',null) from dual;
I need output as Where Salary=5000 and job='Programmer';
Hope am clear,
In short which ever values are not null, those all should include in my where clause,
I know how to do it, but taking into considerations, am finding the best way to do it,
Thanks for your responses,

Answer 1

Hi Karthik,
this is the api, I have done,
create or replace
FUNCTION get_where_clause_for_emp_req (
   emp_id       IN   NUMBER,
   salary            IN   NUMBER,
   job         IN   VARCHAR2,
   dept IN NUMBER
   RETURN VARCHAR2
IS
   l_where_clause   VARCHAR2 (2000);
BEGIN
   IF (    (emp_id IS NULL)
       AND (salary IS NULL)
       AND (job IS NULL)
       AND (deptIS NULL)
   THEN
      RETURN NULL;
   ELSE
      l_where_clause := 'WHERE ';
   END IF;
   IF (emp_id IS NOT NULL)
   THEN
      l_where_clause :=
                    l_where_clause || ' emp_id =' || emp_id || '';
   END IF;
   IF ((emp_id IS NOT NULL) AND (salary IS NOT NULL))
   THEN
      l_where_clause :=
                      l_where_clause || ' AND salary= ' || salary;
   ELSIF (salary IS NOT NULL)
   THEN
      l_where_clause := l_where_clause || ' salary= ' || salary;
   END IF;
   IF (((salary IS NOT NULL) AND (dept IS NOT NULL)) OR ((emp_id IS NOT NULL) AND (salary IS NULL) AND (dept IS NOT NULL)))
   THEN
      l_where_clause := l_where_clause || ' AND dept= ' || dept;
   ELSIF (status_i IS NOT NULL)
   THEN
      l_where_clause := l_where_clause || ' dept= ' || dept;
   END IF;
l_where_clause := l_where_clause || ' ;';
   RETURN l_where_clause;
END;I have done for three parameters, i need to include two more input parameters for this function, so I see going forward my testing cases will increases,
so am looking for the best solution
Thanks
Edited by: NSK2KSN on Jul 7, 2010 3:11 PM