如何使用Codeigniter计算组中的项目？

I am using active record to return a grouped list of dates with the following code:

我使用活动记录返回日期的分组列表，其中包含以下代码：

function get_archive_links(){

        $this->db->order_by('date','desc');
        $this->db->group_by('MONTH(date), YEAR(date)');
        $query = $this->db->get('blog'); 

    foreach ($query->result() as $row) {
        $data[] = array(
            'id' => $row->id,
            'date' => $row->date
        );
    }

    return $data;
}

Which when looped and echoed on my page returns:

在我的页面上循环和回显时返回：

Febuary 2012
2012年2月
January 2012
2012年1月
December 2012
2012年12月

How can I count each item in the group and display it in my list? Example:

如何计算组中的每个项目并将其显示在列表中？例：

Febuary 2012 (2)
2012年2月（2）
January 2012 (6)
2012年1月（6）
December 2012 (7)
2012年12月（7）

I will be counting how many blog posts there where for each month.

我将计算每个月有多少博客帖子。

4 个解决方案

#1

You need to either remove the GROUP BY then count in PHP, or add a ->select('COUNT(id) AS num_posts') to your AR query. I'd probably add the ->select(), as it's less work :)

您需要删除GROUP BY然后在PHP中计数，或者在AR查询中添加 - > select（'COUNT（id）AS num_posts'）。我可能会添加 - > select（），因为它的工作量较少:)

#2

You can it with sql count function. if you are using group by, count function returning count rows for row group.

你可以使用sql count函数。如果您正在使用group by，则count函数返回行组的计数行。

like this,

喜欢这个，

function get_archive_links(){
    $this->db->select("count(*) as count, blog.*);
    $this->db->order_by('date','desc');
    $this->db->group_by('MONTH(date), YEAR(date)');
    $query = $this->db->get('blog'); 

    foreach ($query->result() as $row) {
        $data[] = array(
            'id' => $row->id,
            'date' => $row->date,
            'count' => $row->count
        );
    }

return $data;

}

#3

This works perfect but not shows zero counts if not exist post for category

这种方法很完美，但如果不存在类别，则不显示零计数

here is my function,

这是我的功能，

function get_category_list()
{
    $this->db->select("count(*) as num_posts,cb_category.*");
    $this->db->where_in('cb_post.city', $city_ids);
    $this->db->join('cb_posts', 'cb_post.category = cb_category.cat_id or cb_post.parent = cb_category.cat_id', 'left');

    $this->db->order_by('cat_name_en', 'ASC');

    $this->db->group_by('cb_category.cat_id');

    $query = $this->db->get('cb_category');

}

#4

SELECT
  categories.*,
  COUNT(posts.category_id) AS `count`
FROM
  (categories
LEFT JOIN
    posts 
ON posts.category_id = categories.category_id)
GROUP BY
  Category_name;

I've got the answer for the zero count issue.

我得到零计数问题的答案。

#1