Не пойму куда пропадает 706ой топик. Разве при LEFT JOIN не должны сохраняться все поля из левой таблицы?
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mysql> select topic_id from topics;
+ ----------+
| topic_id |
+ ----------+
| 1 |
| 2 |
| 3 |
| 105 |
| 706 |
+ ----------+
5 rows in set ( 0 . 01 sec)
mysql> select topics.topic_id from topics LEFT JOIN vote USING (topic_id) GROUP
BY vote.topic_id;
+ ----------+
| topic_id |
+ ----------+
| 105 |
| 1 |
| 2 |
| 3 |
+ ----------+
4 rows in set ( 0 . 00 sec)
Вот структура, на всякий случай:
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create table topics (
topic_id integer unsigned not null primary key auto_increment,
login char( 255 ),
title char( 255 ),
date timestamp not null,
size integer unsigned not null,
ip char( 15 ),
section char( 15 ),
text mediumtext);
create table vote (
vote_id integer unsigned not null primary key auto_increment,
topic_id integer not null,
date timestamp not null,
vote integer,
ip char( 15 ));
