从 Codeigniter Active Record 中的子查询中选择

Question

我将如何在 Codeigniter ActiveRecord 中执行以下查询：-

SELECT *, 

(SELECT 
        image_path
    FROM
        image
    WHERE
        image_table = 'model'
            AND image_table_id = model_id
    GROUP BY image_table_id
    LIMIT 1) AS ModelImg 

FROM

   (SELECT 
      *
   FROM
      vw_newcars
    where offer_table = 'derivative'
    order by offer_order
   ) x

WHERE make_name = 'Fiat'
group by offer_table_id
limit 12

我遇到的问题是如何从 Active Record 中的子查询中进行选择。

我在文档中没有看到 from_select 函数或任何类似的东西。

Answer 1

我设法通过将from sub_query 放入初始选择语句来使查询工作：

$this->db->select("*, 
  (select image_path from image where image_table = 'model' and image_table_id = model_id
  group by image_table_id limit 1) as ModelImg FROM 
  (SELECT * FROM $view where offer_table = 'derivative' order by offer_order) x");