Dynamic Formula Creation

Question

Hi,
I want to derive a formula based on the below table.
LINE_NO
OPERATOR
VARIABLE
1
A
2
+
B
3
C
4
D
5
6
+
E
7
8
F
9
G
10
The formula will always concatenate the operator with the variable for each step and it will formulate a complete formula at the end by concatenating the operator and variable columns in each step.
so if i formulate it , the formula would be A+B(C/D)+E*(F/G)
I want the formula to be generated dynamically at the run time.
Could any body please help me in how to formulate it?
Any immediate help is highly appreciated.

Answer 1

Here we go... not difficult to put it in PL/SQL...
SQL> select * from fm;
   LINE_NO O V
         1   A
         2 + B
         3 *
         4 ( C
         5 / D
         6 )
         7 + E
         8 *
         9 ( F
        10 / G
        11 )
11 rows selected.
SQL> set serverout on
SQL> ed
Wrote file afiedt.buf
  1  declare
  2    a number := 3;
  3    b number := 4;
  4    c number := 6;
  5    d number := 2;
  6    e number := 3;
  7    f number := 6;
  8    g number := 2;
  9    formula varchar2(100);
10    result  number;
11  begin
12   select x.formula
13         ,to_number(y.column_value) as result
14   into formula, result
15   from (
16         select replace(sys_connect_by_path(replace(operator,'/',' div ')||
17                                            decode(variable,'A',a,'B',b,'C',c,'D',d,'E',e,'F',f,'G',g)
18                                           ,'~'),'~') as formula
19         from   fm
20         where connect_by_isleaf = 1
21         connect by line_no = prior line_no + 1
22         start with line_no = 1
23        ) x
24       ,xmltable(x.formula) y;
25    --
26    dbms_output.put_line('Formula: '||formula);
27    dbms_output.put_line('Result : '||result);
28* end;
SQL> /
Formula: 3+4*(6 div 2)+3*(6 div 2)
Result : 24
PL/SQL procedure successfully completed.