Jorgen Loland a écrit, Le 23.06.2011 14:02:
> Hi Guilhem,
>
> Patch is approved, but I find the return statement unnecessary hard to
> read. Please see below.
>
>> === modified file 'sql/sql_select.h'
>> --- a/sql/sql_select.h 2011-06-17 12:45:22 +0000
>> +++ b/sql/sql_select.h 2011-06-20 14:29:59 +0000
>> @@ -2029,10 +2029,16 @@ public:
>> void clear();
>> bool save_join_tab();
>> bool init_save_join_tab();
>> + /**
>> + If there is an aggregate function (sum_func_count!=0), and no
>> GROUP BY,
>> + and the HAVING clause evaluates to "true", we should send a row
>> even if
>> + the join contains no rows. This is what the standard requires.
>> + */
>> bool send_row_on_empty_set()
>> {
>> return (do_send_rows&& tmp_table_param.sum_func_count !=
> 0&&
>> - !group_list&& select_lex->having_value !=
> Item::COND_FALSE);
>> + !(group_list != NULL || group_optimized_away)&&
>> + select_lex->having_value != Item::COND_FALSE);
>
> This double-negation makes me dizzy. Instead of "!(!A || B)" you can use
> "A && !B" and get this, which I find way more readable:
>
> return (do_send_rows && tmp_table_param.sum_func_count != 0 &&
> group_list==NULL && !group_optimized_away &&
> select_lex->having_value != Item::COND_FALSE);
done
