Create JSON from Query with tjsonDocOutput

[Anonymous]

Hello,

I am new to the tjsonDoc* components. I read the documentation from jlolling but still not sure how to create the following json from a (one?) database query

{
  "data": {
    "masters": [
      {
        "master_number": "12345678912",
        "origin": "BER",
        "destination": "FRA",
        "items": 2
      }
    ],
    "items": [
      {
        "master_number": "12345678912",
        "item_number": "1",
        "item_origin": "BER"
      },
      {
        "master_number": "12345678912",
        "item_number": "2",
        "item_origin": "BER"
       }
     ]
   }
}

Is it neccessary to query the database twice, once for master and again for child data (items)?So far I created the following:

But I get (as configured in the job) a json array with objects containing master and item data in it:

 "masters": [
    {
  	"master_number" : "12345678912",
  	"origen" : "BER",
  	"destination" : "FRA",
  	"items" : 2
 	"item_number": "1",
        "item_origin": "BER"
    }, 
    {
  	"master_number" : "12345678912",
  	"origen" : "BER",
  	"destination" : "FRA",
  	"items" : 2
 	"item_number": "2",
        "item_origin": "BER"

    }, 
...

So it puts every row and corresponding columns to one new json objects. How to split it into one master and its items? I guess I should use forreign key structure?

Could someone give me a hint for the basic job structure?