How to serialize object properties into a multidimensional structure?

Question

Laravel

I use the Laravel framework, so when I make a request to the database, I get the following structure as a result:

Collection {#288 ▼
  #items: array:7 [▼
    0 => {#323 ▼
      +"record_id": 1
      +"city_id": 4
      +"value": "90"
      +"from_date": "2017-11-01 00:00:00"
      +"to_date": "2018-11-30 23:59:59"
    }
    1 => {#321 ▼
      +"record_id": 2
      +"city_id": 4
      +"value": "70"
      +"from_date": "2018-12-01 00:00:00"
      +"to_date": "2019-03-31 23:59:59"
    }
    2 => {#324 ▶}
    3 => {#326 ▶}
    4 => {#327 ▶}
    5 => {#328 ▶}
    6 => {#329 ▶}
  ]
}

How to bring it using Eloqunet or native php to

mind

Collection {#288 
  #items: array:3 [
   + city_id(4) => {
      + value(90) => {
         +"from_date": "2017-11-01 00:00:00"
         +"to_date": "2018-11-30 23:59:59"
       }
       + value(70) => {
         +"from_date": "2018-12-01 00:00:00"
         +"to_date": "2019-11-30 23:59:59"
       }
    }
    + city_id(3) => {
    //etc
    }
}

There are many methods in the Eloquenet documentation that allow you to get a similar result, but perhaps due to the lack of a complete understanding of how to achieve the result, it does not work for me. So far the best I have

came out:

Collection {#345 ▼
  #items: array:3 [▼
    4 => Collection {#338 ▼
      #items: array:3 [▼
        90 => Collection {#335 ▼
          #items: array:1 [▼
            0 => {#323 ▼
              +"value": "90"
              +"from_date": "2017-11-01 00:00:00"
              +"to_date": "2018-11-30 23:59:59"
            }
          ]
        }
        70 => Collection {#336 ▶}
        60 => Collection {#337 ▶}
      ]
    }
    3 => Collection {#341 ▼
      #items: array:2 [▼
        90 => Collection {#339 ▼
          #items: array:1 [▼
            0 => {#326 ▼
              +"value": "90"
              +"from_date": "2017-11-01 00:00:00"
              +"to_date": "2019-02-28 23:59:59"
            }
          ]
        }
        60 => Collection {#340 ▶}
      ]
    }
    10 => Collection {#344 ▶}
  ]
}

Almost, but because of the intermediate array at the end, calling the desired property will look like city_id->value[0]->property, which is not very good, because then the data will need to be packed into json and then it will work on the client side. How to do it right?

Answer 1

->groupBy('city_id')
edit:->groupBy('city_id')->map->groupBy('value')