Mysql 计算并显示特定列结果的数量

我有下表

|id|city|job|
|12|New York|Truck driver|
|13|Chicago|Postman|
|14|New York|Postman|
|15|Las Vegas|Dealer|
|16|Las Vegas|Dealer|
|17|New York|Post Office|

我希望能够计算出每个城市有多少个工作岗位，然后按描述顺序返回工作岗位最多的十个城市。像下面这样

• 纽约（3）
• 拉斯维加斯（2）
• 芝加哥（1）

我如何做到这一点

我的代码如下所示

 $this->db->select('city');
 $this->db->select_sum('city', 'total');
 $this->db->group_by('city'); 
 $this->db->order_by('total', 'desc'); 
 $query = $this->db->get('job', 10);

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

return $data;

我从这条线索中得到了灵感：

---

但是似乎做得不对。

为什么不使用

$this->db->query（）

给你：-

$query = $this->db->query('SELECT city, COUNT(city) AS jobcount FROM `jobs` GROUP BY city ORDER BY jobcount DESC');

if ($query->num_rows() > 0)
    foreach ($query->result() as $row) 
        $data[] = array(
            'total' => $row->jobcount,
            'city'  => $row->city
        );

return $data;

别忘了用您的表名交换
“作业”
，或者添加一个限制（mysql/TOP用于mssql）？
$query = $this->db->query('SELECT city, COUNT(city) AS jobcount FROM `jobs` GROUP BY city ORDER BY jobcount DESC');

if ($query->num_rows() > 0)
    foreach ($query->result() as $row) 
        $data[] = array(
            'total' => $row->jobcount,
            'city'  => $row->city
        );

return $data;