如何执行查询由动态SQL组成，而动态SQL子句由绑定参数组成

Question

stmt_ := 'SELECT col1,col2, ;
   stmt_ := stmt_ || ' FROM TABLE';

   group_by_ := ' GROUP BY col3,col4';

   IF (source_ref_ = 'INVOICE') THEN
      stmt_ := stmt_ || ' WHERE col3= :Col_3_val AND col4= :Col_4_val '; 
   ELSE
      stmt_ := stmt_ || ' WHERE col2= :Col_2_val AND col3= :Col_3_val AND col4= :Col_4_val'; 
   END IF; 
stmt_ := stmt_ + group_by

我们是否可以通过一个EXECUTE命令执行此查询