Question

帖子图表;

ID           post_date 
1      2013-10-20:01:00:00
6      2013-09-20:01:00:00

term_relationships Chart;

object_id    term_taxonomy_id    term_order

1               1                    0
1               2                    0
1               3                    0
6               1                    0
6               1                    0

term_taxonomy图表;

term_taxonomy_id     term_id    taxonomy    parent
1                     1         category      0
2                     2         post_tag      0
3                     3         post_tag      0
4                     4         category      1

-

$post = $wpdb->get_results("SELECT `p`.`ID`, MAX(p.post_date) as `datetime`, `p`.`post_date`, `p`.`post_content`, `p`.`post_title`, `p`.`post_status`, `p`.`post_name`, `p`.`comment_count`, `tax`.`term_taxonomy_id`, `tax`.`term_id`, `tax`.`taxonomy`, `tax`.`parent`, `rel`.`object_id`, `rel`.`term_taxonomy_id`

FROM (`$wpdb->posts` AS p)

INNER JOIN `$wpdb->term_relationships` AS rel ON `rel`.`object_id` = `p`.`ID`

INNER JOIN `$wpdb->term_taxonomy` AS tax ON `tax`.`term_taxonomy_id` = `rel`.`term_taxonomy_id`

WHERE `tax`.`taxonomy` =  'category'AND `p`.`post_status` = 'publish' AND `p`.`post_type` =  'post'

GROUP BY tax.parent

ORDER BY datetime DESC LIMIT 4

");

tax.parent =顶级类别ID post_date类型数据类型

ORDER BY datetime DESC =排序不正确：（

Answer 1

    select l.* 
    from table l
    inner join (
      select 
        m_id, max(timestamp) as latest 
      from table 
      group by m_id
    ) r
      on l.timestamp = r.latest and l.m_id = r.m_id
    order by timestamp desc

print your query and enter on phpmyadmin. we get exactly error . so you know easily what you want change

Answer 2

尝试使用表别名:: OREDER BY p.post_date DESC

Php mysql命令由datetime desc

2 个答案: