codeigniter 中的活动记录答案

【问题标题】：Active record in codeignitercodeigniter 中的活动记录
【发布时间】：2013-01-01 11:34:01
【问题描述】：

任何人都可以将此查询转换为活动记录代码点火器？？？

 SELECT  b.name,
    SUM(CASE WHEN c.size = 'S' THEN 1 ELSE 0 END) S,
    SUM(CASE WHEN c.size = 'M' THEN 1 ELSE 0 END) M,
    SUM(CASE WHEN c.size = 'L' THEN 1 ELSE 0 END) L,
    SUM(CASE WHEN c.size = 'XL' THEN 1 ELSE 0 END) XL
   FROM    orderTB a
    INNER JOIN productTB b
        ON a.id_product = b.id_shirt
    INNER JOIN sizeTB c
        ON a.id_size = c.id_size
GROUP BY b.name

我试过这样

  function get()
 {
  $this->db->select("b.name,SUM(CASE WHEN c.size ='S' THEN 1 ELSE 0 END) as S,SUM(CASE    WHEN c.size = 'M' THEN 1 ELSE 0 END) as M,SUM(CASE WHEN c.size = 'L' THEN 1 ELSE 0 END) as   L,SUM(CASE WHEN c.size = 'XL' THEN 1 ELSE 0 END) as XL");

 $this->db->from('order');
 $this->db->join('ukuran','order.id_size=ukuran.id_size');
 $this->db->where('date',$date);
 return $this->db->get();
 }

但是错了

【问题讨论】：

你不应该有SELECT b.name, c.size, COUNT(*) FROM ... GROUP BY b.name, c.size，然后再重新组织数据吗？
将 FALSE 作为第二个参数添加到您的选择中

标签： mysql codeigniter activerecord php

【解决方案1】：

试试这个，然后告诉我，

$this->db->select("b.name,SUM(CASE WHEN c.size = 'S' THEN 1 ELSE 0 END) S,SUM(CASE WHEN c.size = 'M' THEN 1 ELSE 0 END) M,SUM(CASE WHEN c.size = 'L' THEN 1 ELSE 0 END) L,SUM(CASE WHEN c.size = 'XL' THEN 1 ELSE 0 END) XL", FALSE );
$this->db->from('orderTB a');
$this->db->join('productTB b','a.id_product = b.id_shirt','inner');
$this->db->join('sizeTB c','a.id_size = c.id_size','inner');
$this->db->group_by('b.name');

来自文档here

$this->db->select() 接受可选的第二个参数。如果你设置它为 FALSE，CodeIgniter 不会尝试保护您的字段或表带有反引号的名称。如果您需要复合选择，这很有用声明。

编辑

只需在您的选择语句中添加FALSE

function get() {
    $this->db->select("b.name,SUM(CASE WHEN c.size ='S' THEN 1 ELSE 0 END) as S,SUM(CASE    WHEN c.size = 'M' THEN 1 ELSE 0 END) as M,SUM(CASE WHEN c.size = 'L' THEN 1 ELSE 0 END) as   L,SUM(CASE WHEN c.size = 'XL' THEN 1 ELSE 0 END) as XL",FALSE);

    $this->db->from('order');
    $this->db->join('ukuran','order.id_size=ukuran.id_size');
    $this->db->where('date',$date);
    return $this->db->get();
}

【讨论】：