Question

我正在尝试显示所有博客，无论是否有与之相关的评论但是我有1个问题，因为它们如下：

并非显示COMMENTS TABLE和ENTRY TABLE中的所有字段（如果没有显示重复的字段名称，但是，如您所见，我使用完整的字段名称，例如.tablename.fieldname）< / LI>

这是我的模特：

类A_User_Blog_Comments_model扩展CI_Model {

public function get_blog($id) {
        $this->db->select('
            entry.user_id,
            entry.entry_id,
            entry.entry_name,
            entry.entry_body,
            entry.status,
            entry.created_timestamp,
            entry.updated_timestamp,
            comments.id,
            comments.comment,
            comments.user_id,
            comments.blog_id,
            comments.status,
            comments.created_timestamp,
            comments.updated_timestamp
        ');
        $this->db->from('entry'); 
        $this->db->join('comments', 'entry.entry_id=comments.blog_id', 'left');
        $this->db->where('entry.entry_id',$id);
        $query = $this->db->get(); 
        if($query->num_rows() != 0)
        {
            return $query->result_array();
        }
        else
        {
            return false;
        }
 }

以下是我的视图文件中的简单转储：

 Array
 (
[0] => Array
    (
        [user_id] => 1
        [entry_id] => 1
        [entry_name] => twkla nnn xxx
        [entry_body] => this is just UPDATED
        [status] => active
        [created_timestamp] => 2017-01-03 00:00:00
        [updated_timestamp] => 2017-01-04 00:00:00
        [id] => 1
        [comment] => This is a comment
        [blog_id] => 1
    )

[1] => Array
    (
        [user_id] => 1
        [entry_id] => 1
        [entry_name] => twkla nnn xxx
        [entry_body] => this is just UPDATED
        [status] => active
        [created_timestamp] => 2016-12-04 00:00:00
        [updated_timestamp] => 2017-01-03 00:00:00
        [id] => 2
        [comment] => This is another comments
        [blog_id] => 1
    )

 )

但是，正如您所看到的，视图中缺少许多字段，因为这是执行的SQL：

 SELECT  `entry`.`user_id` ,  `entry`.`entry_id` ,  `entry`.`entry_name` ,       
 `entry`.`entry_body` ,  `entry`.`status` , `entry`.`created_timestamp` ,  
 `entry`.`updated_timestamp` ,  `comments`.`id` ,  `comments`.`comment` , 
 `comments`.`user_id` ,  `comments`.`blog_id` ,  `comments`.`status` ,  
 `comments`.`created_timestamp` , `comments`.`updated_timestamp` 
 FROM  `entry` 
 LEFT JOIN  `comments` ON  `entry`.`entry_id` =  `comments`.`blog_id` 
 WHERE  `entry`.`entry_id` =1

为什么显示所有字段？

Answer 1

您在＆＃34;条目＆＃34;中有相同的列名称表以及＆＃34;评论＆＃34;像user_id，status等...具有相同的列名，然后将返回主表值。只需为下面的匹配列创建别名。

comments.user_id为cuser_id，comments.status为cstatus

Answer 2

用这个替换你的select语句。

    $this->db->select('
    entry.user_id as euid,
    entry.entry_id,
    entry.entry_name,
    entry.entry_body,
    entry.status as entry_status ,
    entry.created_timestamp as entry_addtime,
    entry.updated_timestamp as entry_updatetime,
    comments.id as comments_id,
    comments.comment,
    comments.user_id as comments_userID,
    comments.blog_id,
    comments.status as comments_status,
    comments.created_timestamp as comments_addtime,
    comments.updated_timestamp as comments_addtime
');

Codeigniter 3.x - 左连接和显示字段问题

2 个答案: