Child relationship mapping schema NReco.GraphQL documentation

It is possible to define a single child object (one-to-one) or multiple child objects (one-to-many) with RelatedObjects section in of the object's schema. Nested query to child objects may include a filter, sort, aggregate fields, and pagination parameters. In case of multiple queries, N+1 problem is solved with DataLoader that reduces number of SQL queries (see when DataLoader is used for loading nested objects).

{
 "SchemaObjects": [
  {
   "SingleName": "company",
   "ListName": "companies",
   "Table": "Companies",
   "Description": "Companies table - contains data about the best companies ever",
   "Fields": [
    {
     "Name": "id",
     "Column": "ID",
     "DataType": "string",
     "Description": "Unique identificator - using also to connect with contact"
    },
    {
     "Name": "title",
     "DataType": "string"
    }
   ],
   "RelatedObjects": [
    {
     "Name": "contact", // refers to the name of related object (single)
     "Relex": "Contacts(company_id=\"id\":var)[*]" // query used to load related object
    },
	{
     "Name": "contacts", // refers to the name of related objects (an array)
     "Relex": "Contacts(company_id=\"id\":var)[*]" // query used to load related object
    }
   ]
  },
  {
   "SingleName": "contact",
   "ListName": "contacts",
   "Table": "Contacts",
   "Fields": [
    {
     "Name": "id",
     "Column": "ID",
     "DataType": "int32"
    },
    {
     "Name": "first_name",
     "Column": "FirstName",
     "DataType": "string"
    },
    {
     "Name": "last_name",
     "DataType": "string"
    }
   ]
  }
 ]
}

Fetching child (nested) objects

																			
query {
	company {
		id
		contact {
			id
			first_name
		}
	}
}

{
	"data": {
		"company": {
			"id": 1,
			"title": "NReco Inc.",
			"contact": {
				"id": 1,
				"first_name": "Dave"
			}
		}
	}
}