public function getEnumAsSqlString()
 {
     if ($this->equals(class_orm_comparator_enum::GreaterThen())) {
         return ">";
     }
     if ($this->equals(class_orm_comparator_enum::GreaterThenEquals())) {
         return ">=";
     }
     if ($this->equals(class_orm_comparator_enum::LessThen())) {
         return "<";
     }
     if ($this->equals(class_orm_comparator_enum::LessThenEquals())) {
         return "<=";
     }
     if ($this->equals(class_orm_comparator_enum::Equal())) {
         return "=";
     }
     if ($this->equals(class_orm_comparator_enum::NotEqual())) {
         return "!=";
     }
     if ($this->equals(class_orm_comparator_enum::Like())) {
         return "LIKE";
     }
     throw new class_orm_exception("Unknown sql comparator", class_exception::$level_ERROR);
 }