根据codeigniter中的外键从两个表中获取json编码数据答案

【问题标题】：Get json encode data from two tables on the basis of foreign key in codeigniter根据codeigniter中的外键从两个表中获取json编码数据
【发布时间】：2018-03-25 15:22:25
【问题描述】：

我有一个问题要问你，我还没有找到解决方案，所以我有 2 个表：

分类：

id  category

1   BBA
2   BSCS
3   BEE

子类别：

id  category_id sub_category_name
1       1           Accountant
2       1           Manager
3       1           Sales
4       2           Data Adminsitrator
5       2           Web Developer
6       3           Airline Pilot
7       3           Airport Security Screener
8       3           Aircraft Mechanic

我想从第一个表中加入两个表，我想获取类别，在类别下我想要所有子类别

我的控制器如下所示：

public function getVehicles()
    {
        $result = $this->crud_m->getUserVehicles($data,'vehicle');
        return $this->output->set_output(json_encode(array(     
                'status' => 'OK',
                'statusCode' => '402',
                'response' => array(   
                        'description' => 'Details',
                        'category'=> $result
                )
            )));

        }

我的模型是这样的：

    public function getUserVehicles($data)
        {   
            $this->db->select('*');
            $this->db->from('categories');                      
            $this->db->join('sub_category','sub_category.category_id=categories.id');
            $this->db->group_by('categories.id');
            $query = $this->db->get();
            $result = $query->result();
            if(empty($result)){     
                return '401';
                }
            else{

                return $result; 
            }
        }

我的输出现在是这样的：

{
  "status": "OK",
  "statusCode": "402",
  "response": {
    "description": "Details",
    "category": [
      {
        "id": "1",
        "category": "BBA",
        "category_id": "1",
        "sub_category_name": "Accountant"
      },
      {
        "id": "4",
        "category": "BSCS",
        "category_id": "2",
        "sub_category_name": "Data Adminsitrator"
      },
      {
        "id": "6",
        "category": "BEE",
        "category_id": "3",
        "sub_category_name": "Airline Pilot"
      }
    ]
  }
}

而我需要的是这样的：

[
  {
    "categoryId": "1",
    "category": "BBA",
    "subCategory": [
      {
        "subCategoryId": "1",
        "subCategoryName": "Accountant"

      },
      {
        "subCategoryId": "2",
        "subCategoryName": "Manager"

      },
      {
        "subCategoryId": "3",
        "subCategoryName": "Sales"

      }
    ]
  },
  {
    "categoryId": "2",
    "category": "BSCS",
    "subCategory": [
      {
        "subCategoryId": "4",
        "subCategoryName": "Data Adminsitrator"

      },
      {
        "subCategoryId": "5",
        "subCategoryName": "Web developer"

      }
    ]
  }
]

【问题讨论】：

您需要从类别记录集中获得一个 for 循环，并将其附加到返回数组中。
删除 $this->db->group_by('categories.id'); 然后你将拥有所有行。循环结果并根据您的要求创建单独的数组

标签： php mysql json codeigniter

【解决方案1】：

您可以使用以下代码随意获取数据。

    public function getUserVehicles($data)
    {   
        $categories = array();
        $this->db->select('*');
        $this->db->from('categories');                      
        $query = $this->db->get();
        $result = $query->result();
        foreach($result as $r){
            $r['subCategory'] = $this->getSubCategory($r['id']);
            array_push($categories, $r);
        }
        if(empty($result)){     
            return '401';
        }else{
            return $categories; 
        }
    }


        public function getSubCategory($cat)
    {   
        $this->db->select('*');
        $this->db->from('sub_category');      
        $this->db->where('id', $cat);
        $query = $this->db->get();
        $result = $query->result();
        return $result; 
    }

【讨论】：