17 Access Patterns with GraphQL and AWS Amplify

schema.graphql

type Order @model
  @key(name: "byCustomerByStatusByDate", fields: ["customerID", "status", "date"])
  @key(name: "byCustomerByDate", fields: ["customerID", "date"])
  @key(name: "byRepresentativebyDate", fields: ["accountRepresentativeID", "date"])
  @key(name: "byProduct", fields: ["productID", "id"])
{
  id: ID!
  customerID: ID!
  accountRepresentativeID: ID!
  productID: ID!
  status: String!
  amount: Int!
  date: String!
}

type Customer @model
  @key(name: "byRepresentative", fields: ["accountRepresentativeID", "id"]) {
  id: ID!
  name: String!
  phoneNumber: String
  accountRepresentativeID: ID!
  ordersByDate: [Order] @connection(keyName: "byCustomerByDate", fields: ["id"])
  ordersByStatusDate: [Order] @connection(keyName: "byCustomerByStatusByDate", fields: ["id"])
}

type Employee @model
  @key(name: "newHire", fields: ["newHire", "id"], queryField: "employeesNewHire")
  @key(name: "newHireByStartDate", fields: ["newHire", "startDate"], queryField: "employeesNewHireByStartDate")
  @key(name: "byName", fields: ["name", "id"], queryField: "employeeByName")
  @key(name: "byTitle", fields: ["jobTitle", "id"], queryField: "employeesByJobTitle")
  @key(name: "byWarehouse", fields: ["warehouseID", "id"]) {
  id: ID!
  name: String!
  startDate: String!
  phoneNumber: String!
  warehouseID: ID!
  jobTitle: String!
  newHire: String! # We have to use String type, because Boolean types cannot be sort keys
}

type Warehouse @model {
  id: ID!
  employees: [Employee] @connection(keyName: "byWarehouse", fields: ["id"])
}

type AccountRepresentative @model
  @key(name: "bySalesPeriodByOrderTotal", fields: ["salesPeriod", "orderTotal"], queryField: "repsByPeriodAndTotal") {
  id: ID!
  customers: [Customer] @connection(keyName: "byRepresentative", fields: ["id"])
  orders: [Order] @connection(keyName: "byRepresentativebyDate", fields: ["id"])
  orderTotal: Int
  salesPeriod: String
}

type Inventory @model
  @key(name: "byWarehouseID", fields: ["warehouseID"], queryField: "itemsByWarehouseID")
  @key(fields: ["productID", "warehouseID"]) {
  productID: ID!
  warehouseID: ID!
  inventoryAmount: Int!
}

type Product @model {
  id: ID!
  name: String!
  orders: [Order] @connection(keyName: "byProduct", fields: ["id"])
  inventories: [Inventory] @connection(fields: ["id"])
}

Quick question here, let's say if we had to make it multiple products in a order, how would you do multiple products mutations in an order? Is batch update mutations is possible?

I'm currently facing the same task. I want to insert multiple entries for a given table. If you want batch updates you can do it with a custom resolver or with a lambda function.

Via Custom Resolver
https://medium.com/@jan.hesters/creating-graphql-batch-operations-for-aws-amplify-with-appsync-and-cognito-ecee6938e8ee
I would prefer this approach but honestly I can't get this to work. My issue is still here: https://stackoverflow.com/questions/61045181/aws-amplify-custom-resolver-unsupported-operation-batchputitem

Maybe you have more luck

Via Lambda function
I wrote a blog post some time ago how you can insert multiple entries to a dynamodb table
https://regenrek.com/posts/using-aws-lambda-insert-multiple-json-dynamodb/

Great example for Relational Data with DynamoDB and Amplify!
One questions, as all types are annotated with the @model directive, amplify will, in this cases, still generate 7 DynamoDB tables behind the scenes?
Or will it use a single table like it is advised in the adjacency list pattern?

That´s my question too !

I also would like to understand how to "manually" use the directives, in particular @connection for a one-to-one relationship. I had already written the resolvers (VLT scripts) needed for my "single" queries but need to retrieve additional info for an certain graphql type object, from a record in the same DynamoDB table. All without using the magic "create resources" option...

How to construct the appropriate query-resolver ?

Some where along the line:

type Project @model {
id: ID!
name: String
teamID: ID!
team: Team @connection(fields: ["teamID"])
}

type Team @model {
id: ID!
name: String!
}