如何查询多2个表

Question

我尝试这样做：

    $sql = "SELECT phpbb_users.user_id, phpbb_users.username, phpbb_users.user_colour, topic_poster, phpbb_topics.forum_id, phpbb_forums.forum_price
FROM phpbb_topics LEFT JOIN phpbb_forums ON phpbb_topics.forum_id = phpbb_forums.forum_id
 LEFT JOIN phpbb_users ON phpbb_topics.topic_poster = phpbb_users.user_id WHERE phpbb_users.group_id = '55222'
 OR phpbb_users.group_id = '55229'
 OR phpbb_users.group_id = '55174'
 GROUP BY phpbb_users.user_id ORDER BY phpbb_forums.forum_price DESC";
    $result = $db->sql_query($sql);

while ($row = $db->sql_fetchrow($result))
{

    $template->assign_block_vars('earn', array(
        'USER_ID'                   => $row['user_id'],
        'USERNAME'                  => $row['username'],
        'USER_COLOR'                => $row['user_colour'],
        'U_USER'                    => append_sid($phpbb_root_path . "memberlist." . $phpEx . "?mode=viewprofile&u=" . $row['user_id']),
        'TOTAL_EARN'                => $price,
        'TOTAL_UPLOADS'             => $total_price_singels+$total_price_albums,
        'TOTAL_UPLOADS_LASTMONTH'   => $total_upload_lastmonth,
        'TOTAL_UPLOADS_MONTH'       => $total_upload_month,
    ));
}

它不起作用...... 我需要查询每个用户，检查他向各个论坛写了多少条消息，每个论坛都有不同的价格，然后让我得到每个用户再次获得普遍感谢的价格

。

Answer 1

如果我是正确的，那么在 $total_upload_month 之后，您不需要最后一个

$sql = "SELECT phpbb_users.user_id, phpbb_users.username, phpbb_users.user_colour, topic_poster, phpbb_topics.forum_id, phpbb_forums.forum_priceFROM phpbb_topics LEFT JOIN phpbb_forums ON phpbb_topics.forum_id = phpbb_forums.forum_id LEFT JOIN phpbb_users ON phpbb_topics.topic_poster = phpbb_users.user_id WHERE phpbb_users.group_id = '55222' OR phpbb_users.group_id = '55229' OR phpbb_users.group_id = '55174' GROUP BY phpbb_users.user_id ORDER BY phpbb_forums.forum_price DESC";
$result = $db->sql_query($sql);
while ($row = $db->sql_fetchrow($result)){
 $template->assign_block_vars('earn', array(        
'USER_ID'                   => $row['user_id'],        
'USERNAME'                  => $row['username'],        
'USER_COLOR'                => $row['user_colour'],        
'U_USER'                    => append_sid($phpbb_root_path . "memberlist." . $phpEx . "?mode=viewprofile&u=" . $row['user_id']),        
'TOTAL_EARN'                => $price,        
'TOTAL_UPLOADS'             => $total_price_singels+$total_price_albums,        
'TOTAL_UPLOADS_LASTMONTH'   => $total_upload_lastmonth,        
'TOTAL_UPLOADS_MONTH'       => $total_upload_month    
));
}

Answer 2

如果我理解正确，您想要计算每个用户的总和，请尝试如下操作：
选择 sum(phpbb_forums.price) 作为total_sum， ...