set serverout ondeclare
str varchar2(500);
result number;
begin
str:='456+(45*8)';
exec immediate 'select '||str||' into result from dual';
dbms_output.put_line(result);
end;
str varchar2(500);
result number;
begin
str:='456+(45*8)';
exec immediate 'select '||str||' into result from dual';
dbms_output.put_line(result);
end;
str varchar2(500);
result number;
begin
select yourcolumnname into str from yourtablename;
exec immediate 'select '||str||' into result from dual';
dbms_output.put_line(result);
end;