CODEWITHSUNDEEP
graphql
SomethingsGottaGive
SomethingsGottaGive

Reputation: 1894

graphql - querying multiple tables

I am new to graphql and I need to query multiple tables at once to display some data. I have a dashboard that shows information on a home where it comes from 5 tables: address, person, hostinfo, room, and image. I initially have the person_id to query address table which contains the person_id etc... Here's what a brief scratch up of a uml looks like:

entity Address {
    AddressId BigInteger,
    FK_PersonId BigInteger,
    StreetNumber Integer,
    ...
}

entity HostInfo {
    HostInfoId BigInteger,
    FK_AddressId BigInt,
    HomestayName String,
    ...
}

entity Room {
    RoomId BigInteger,
    FK_HostInfoId BigInteger,
    RoomName String,
    ...
}

entity Image {
    FK_AddressId BigInt,
    FK_RoomID BigInt,
    Name String,
    ....
}

entity Person {
    PersonId,
    FirstName String,
    Age Integer required, //TODO remember to check age
}

My question is, how do I use graphql to grab all the data from these tables using just PersonId? EDIT-------- I refactored the typedefiniton as follows:

    export type Address = {
      StreetNumber: number,
      //..
      Person:Person
    }

    export type HostInfo = {
      HomestayName: string,
      //..
      Person:Person,
      Room:[Room!],
      Address:Address
    }

    export type Room = {
      RoomName: string,
      //..
      RoomImage:[RoomImage!],
      HostInfo:HostInfo
    }

    export type RoomImage = {
      Name: string,
      //..
      Room:Room,
    }

    export type HostInfoImage = {
      Name: string,
      ..
      HostInfo:HostInfo
    }

    export type PersonImage = {
      Name: string,
      //..
      Person:Person
    }

export type Person = {
  FirstName: string,
  ..
  PersonImage:[PersonImage]
  Address:Address
}

and perform the query as so:

query HostInfo($id: ID!) {
  node(id: $id) {
    ... on Person {
      firstName
      address {
        streetNumber
        hostInfo {
            HostName,
            //...
            Room {
                RoomName,
               [RoomImage],
               //....
           }
        }
      }
    }
  }
}

I would explicitly show the relationship both ways in my entities... I was expecting more of a sql(ly) way to do it.

Upvotes: 1

Views: 11054

Answers (1)

David Maze
David Maze

Reputation: 158995

Typically GraphQL would represent all of the links between objects explicitly in the schema: if in your database model an Address references a Person, then your Person GraphQL type would have a list of addresses. In the GraphQL schema language, you might have:

type Person implements Node {
  id: ID!,
  firstName: String,
  age: Int!,
  address: [Address!]!
}

If you knew the ID of a person, a typical query to retrieve much of the available data might hypothetically look like

query Person($id: ID!) {
  node(id: $id) {
    ... on Person {
      firstName
      age
      address {
        streetNumber
        hostInfo { ... }
      }
    }
  }
}

Upvotes: 2

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