How to frame dynamic condition and evaluate them

Question

hi all
i have a table which has 3 columns
col1 col2
coloumn 1 will have relational operators like =,>,< etc
and coloumn 2 will have some values
in a procedure which has a in parameter. i need to check the parameter with the col2 using col1 ie using the relational operator.
for ex
the parameter will be 10 and the operator will be > and the column2 will be 11
how will i do this dynamically and how will i evaluate this conditions
thanks in advance
hari

Answer 1

One approach:
SQL> create or replace function DynamicFunction ( op1 number, operator varchar2, op2 number) return boolean is
2 plsqlBlock varchar2(4000);
3 boolInt integer;
4 begin
5 plsqlBlock :=
6 'declare
7 function ExecFunc return boolean is
8 begin
9 return('||op1||operator||op2||');
10 end;
11 begin
12 if ExecFunc then
13 :result := 1;
14 else
15 :result := 0;
16 end if;
17 end;
18 ';
19
20 execute immediate plsqlBlock using OUT boolInt;
21
22 return(boolInt=1);
23 end;
24 /
Function created.
SQL> show errors
No errors.
SQL>
SQL>
SQL> set serveroutput on
SQL> declare
2 procedure Eval( op1 varchar2, operator varchar2, op2 varchar2 ) is
3 begin
4 DBMS_OUTPUT.put( op1||operator||op2||'=' );
5 if DynamicFunction( op1, operator, op2 ) then
6 DBMS_OUTPUT.put_line( 'TRUE' );
7 else
8 DBMS_OUTPUT.put_line( 'FALSE' );
9 end if;
10 end;
11 begin
12 Eval( 1, '=', 2 );
13 Eval( 2, '>=', '2' );
14 end;
15 /
1=2=FALSE
2>=2=TRUE
PL/SQL procedure successfully completed.
SQL>