SQL conditional AND clause?

Question

In my query I want to add the and clause in query if a specific condition occur. See the where clause of my query

1     and ps.dept=dept.deptid  

2     and ps.sdept=deptsub.deptid 

3     and

4   if(ps.dept<>ps.sdept) 

5    begin

6    deptsub.Parent=dept.deptid 

7  end

8  and ps.deptcategory=deptcat.category

At 4 I want if condition fulfil then 6 should be added in query else not how is this possible.thanks!

Answer 1

How about:

and ps.dept=dept.deptid  
and ps.sdept=deptsub.deptid 
and ( ps.dept=ps.sdept or deptsub.Parent=dept.deptid )
and ps.deptcategory=deptcat.category