Question

场景是我是管理员，我有一个会话，会话表由session_id，coach_name，日期（格式Y-m-d）组成。现在我想计算每个“月”教练的总活动量。所以我的观点是如何在SQL查询中获得此类输出。

所需的输出是每个教练每月的活动量。

Name        | No. of session this month
Coach_name1 =   13
Coach_name2 =   5

这是我当前的查询，它给了我教练的名字，但我不知道如何获得每个月

public function getAll(){
    $query = $this->db->query('SELECT DISTINCT coach_name FROM sessions);
    return $query->result();
}

Answer 1

在查询中使用MySQL MONTH()。所以基本上，如果您的会话表中包含所有数据，请在查询中尝试以下内容。

SELECT DISTINCT(`name`),COUNT(`name`) AS `activity` FROM `session` 
WHERE MONTH(`date`)=8 GROUP BY `name`;

签入SQLFiddle

Answer 2

你必须准备如下的查询：

select 
       coach_name, 
       month(your_date_field), 
       count(1) 
from 
       your_table 
where 
      month(your_date_field) = 8
group by 
       coach_name, month(your_date_field)

哪会返回如下记录，

| coach_name    | month(your_date_field) | count(1)   |
+---------------+------------------------+------------+
| Coach_name1   |                    8   |        x   |
| Coach_name2   |                    8   |        x   |
| Coach_name3   |                    8   |        x   |
+---------------+------------------------+------------+

在codeigniter中

$this->db->select("coach_name, month(your_date_field) as month_number,count(1) as counts");
$this->db->where('month(your_date_field)',8);
$this->db->group_by('coach_name,MONTH(your_date_field)');
$query = $this->db->get('your_table');

// results
foreach ($query->result_array() as $row)
{
        // do this to see array
        print_r($row);

        // to access individual fields
        echo $row['coach_name']; 
        echo $row['month_number'];
        echo $row['counts'];
}

Answer 3

使用此查询获取结果。使用mysql MONTH（）从日期和组中获取月号。您将获得所有月份数据。

SELECT coach_name,
       Count(*) AS activities
FROM   sessions
WHERE  Month(date) = 8 //for specfic month 
GROUP  BY coach_name, Month(date) // for all months

使用此查询根据系统日期动态获取当前月份

SELECT coach_name,
       Count(*) AS activities
FROM   sessions
WHERE  Month(date) = MONTH(CURRENT_DATE()) //for selecting current month.
GROUP  BY coach_name

使用月份的Codeigniter计数？

3 个答案: