Instrument Library API (Grapql)

Introduction

This project is a GraphQL cloud service implemented in Node.js. It facilitates the buying and selling of musical instruments through posts. Users can create selling posts with details about the instrument they want to sell, and potential buyers can query and filter posts to find instruments of interest.

The service utilizes Apollo Server for GraphQL implementation and leverages GraphQL's flexibility in querying specific data needs. The underlying data is managed through resolvers, providing efficient data retrieval.

Apollo Server is a community-driven, open-source GraphQL server that works with any GraphQL schema. It simplifies the process of building GraphQL servers.

graphql is a query language for APIs and a runtime for executing those queries against your data. It allows clients to request only the data they need, providing a more efficient and flexible alternative to traditional REST APIs.

Running the server

Before running the server, make sure to install the necessary dependencies using the following command:

npm install

Start the server by running the following command:

npm start

The server will be accessible at the specified address (standard http://localhost:4000). You can use tools like Apollo Playground or Rested to interact with the GraphQL API

Usage

Queries

instrumentPosts

get all stored instrument posts

query {
  instrumentPosts {
    // Fields to retrieve
  }
}

instrumentTypes

get all stored instrument types

query {
  instrumentTypes {
    // Fields to retrieve
  }
}

locations

get all stored locations

query {
  locations {
    // Fields to retrieve
  }
}

instrumentPostwithID

Get an instrument post by its unique ID.

query {
  instrumentPostwithID(id: "uniqueID") {
    // Fields to retrieve
  }
}

filterInstrumentPosts

Filter instrument posts based on specified criteria.

query {
  filterInstrumentPosts(
    sellerUserName: "username"
    instrumentType: "type"
    instrumentFamily: STRING
    locationName: "location"
    condition: NEW
    priceMin: 100
    priceMax: 500
  ) {
    // Fields to retrieve
  }
}

filterInstrumentTypes

Filter instrument types based on the instrument family.

query {
  filterInstrumentTypes(instrumentFamily: STRING) {
    // Fields to retrieve
  }
}

Mutations

createInstrumentPost

Create a new instrument post.

mutation {
  createInstrumentPost(
    title: "Title"
    description: "Description"
    imageUrl: "Image URL"
    type: "Type"
    age: 3
    condition: NEW
    price: 300.5
    location: { city: "City" }
    seller: { userID: 1, userName: "Username", email: "user@example.com" }
  ) {
    // Fields to retrieve
  }
}

deleteInstrumentPost

Delete an instrument post by its ID.

mutation {
  deleteInstrumentPost(postID: 1) {
    // Fields to retrieve
  }
}

Types and Enumerations

User

type User {
  userID: Int!
  userName: String!
  email: String!
  instrumentsForSale: [InstrumentPost]!
}

UserInput

input UserInput {
  userID: Int!
  userName: String!
  email: String!
}

InstrumentPost

type InstrumentPost {
  id: ID!
  title: String!
  description: String!
  imageUrl: String!
  type: InstrumentType!
  age: Int!
  condition: InstrumentCondition!
  price: Float!
  location: Location!
  seller: User!
}

Location

type Location {
  city: String!
  instrumentsForSale: [InstrumentPost]!
}

LocationInput

input LocationInput {
  city: String!
}

InstrumentType

type InstrumentType {
  name: String!
  family: InstrumentFamily!
  instrumentsForSale: [InstrumentPost]!
}

InstrumentFamily (Enumeration)

enum InstrumentFamily {
  Strings
  Woodwind
  Brass
  Percussion
  Electronic
}

InstrumentCondition (Enumeration)

enum InstrumentCondition {
  NEW
  USED
  OLD
}