How do I use the IF-ELSE condition in a WHERE clause?

Question

I want to merge the condition results of my 2 If statements. First if statement result shows only both 0 result, in second if statement result one of them has to be bigger than 0... 
     If (Inventory) <> 0 Then
        If Apple = "" And Banana = "" Then
     strSQL = strSQL & " AND (myApple = 0 AND myBanana = 0)"
  End If
  End If
     If int(Inventory) <> -1 Then
  If Apple = "" And Banana = "" Then
     strSQL = strSQL & " AND (myApple <> 0 OR myBanana <> 0)"
  End If
  End If
**Want to get something like this**
     If int(Inventory) <> 0 Then
            If Apple = "" And Banana = "" Then
       strSQL = strSQL & " AND ((myApple = 0 AND myBanana = 0) AND (myApple <> 0 AND myBanana <> 0))"
    End If
    End If
    If int(Inventory) <> -1 Then
    If Apple = "" And Banana = "" Then
       strSQL = strSQL & " AND (myApple <> 0 AND myBanana <> 0)"
    End If
    End If
   myApple myBanana
         0       0
         0       0
         0       5
         1       0
         6       0
         0       0
      continue.....

Answer 1

Maybe
with
fruits as
(select null apple,null banana from dual union all
select 'Golden Delicious','Chiquita' from dual union all
select 'Granny Smith',null from dual union all
select null,'Cavendish' from dual
select apple,banana,nvl2(apple,1,0) * nvl2(banana,1,0)
  from fruits
APPLE
BANANA
NVL2(APPLE,1,0)*NVL2(BANANA,1,0)
0
Golden Delicious
Chiquita
1
Granny Smith
0
Cavendish
0
Regards
Etbin