Hot Chocolate:
An Introduction to GraphQL for .NET
Michael Staib MVP
Demo
Ask for what you want
query {
me {
name
feed {
message
from {
name
}
images {
title
url
}
}
}
}
Get what you asked for
{
"data": {
"me": {
"name": "Michael Staib",
"feed": {
"message": "Have just arrived in Seattle for the Microsoft Build 2017 conference. Did some touristy stuff with Rafael Staib to stay awake and fight the jetlag :) I think we'll hit the bar now to have a little wine.",
"from": {
"name": "Michael Staib"
},
"images": {
"title": "Wine Glass",
"url": "http://facebook.com/images/44546654654876.png"
}
}
}
}
}
Get what you asked for
{
"data": {
"me": {
"name": "Michael Staib",
"feed": {
"message": "Have just arrived in Seattle for the Microsoft Build 2017 conference. Did some touristy stuff with Rafael Staib to stay awake and fight the jetlag :) I think we'll hit the bar now to have a little wine.",
"from": {
"name": "Michael Staib"
},
"images": {
"title": "Wine Glass",
"url": "http://facebook.com/images/44546654654876.png"
}
}
}
}
}
query {
me {
name
feed {
message
from {
name
}
images {
title
url
}
}
}
}
GET
https://webservices.amazon.com/onca/xml?
Service=AWSECommerceService&
AWSAccessKeyId=mY-Sup3r-s3cr3!-k3y&
AssociateTag=12345&
Operation=ItemLookup&
ItemId=0316067938&
ResponseGroup=Reviews&
TruncateReviewsAt=256&
IncludeReviewsSummary=False&
Version=2013-08-01&
Timestamp=[YYYY-MM-DDThh:mm:ssZ]&
Signature=[Request Signature]
What is GraphQL?
GraphQL
Business Layer
Storage Layer
GraphQL
Rest
Services
gRPC
Services
...
Client
GraphQL
- Single Source of Truth
- One Endpoint
- One Request
- No over- or under- fetching (N+1)
- Type System
- Real-time
-
Predictability
GraphQL gives clients the power to ask for exactly what they need and nothing more.
Backend Engineer: Hmm. So you’re saying this “GraphQL” will allow any web or native engineer to arbitrarily query basically any field in any backend service, recursively, however they want, without any backend engineers involved?
Frontend Engineer: Yeah, right? It’s amazing!
[…silence…]
Backend Engineer: Guards, seize this person.
type Project {
name: String!
tagline: String
contributors: [User]
@cost(complexity: 10)
}
Describe your data
Operation | GraphQL | REST |
---|---|---|
Read | Query | GET |
Write | Mutation | PUT, POST, PATCH, DELETE |
Events | Subscription | N/A |
Demo
What is GraphQL not?
- Graph Database Query Language
- Bound to a specific data source
- Facebooks version of OData
- Good solution for binary streams
- Limited to HTTP
- Limited to the JavaScript world
Demo
What about
Entity Framework?
Demo
query {
students(where: { OR: [{ lastName: "Bar" }, { lastName: "Baz" }] }) {
firstMidName
lastName
enrollments {
course {
title
}
}
}
}
SELECT "s"."FirstMidName", "s"."LastName", "s"."Id", "t"."Title",
"t"."EnrollmentId", "t"."CourseId"
FROM "Students" AS "s"
LEFT JOIN (
SELECT "c"."Title", "e"."EnrollmentId", "c"."CourseId", "e"."StudentId"
FROM "Enrollments" AS "e"
INNER JOIN "Courses" AS "c" ON "e"."CourseId" = "c"."CourseId"
) AS "t" ON "s"."Id" = "t"."StudentId"
WHERE ("s"."LastName" = 'Bar') OR ("s"."LastName" = 'Baz')
ORDER BY "s"."Id", "t"."EnrollmentId", "t"."CourseId"
Lets make it real-time
Demo
Conclusion
- Iterate faster.
- Request what you need get exactly that.
- Fetch data more efficiently.
- Takes away the complexity of data-fetching.
https://chillicream.com
https://github.com/chillicream/hotchocolate
NDC Porto 2020 - Hot Chocolate: An Introduction to GraphQL on ASP.NET Core
By Michael Ingmar Staib
NDC Porto 2020 - Hot Chocolate: An Introduction to GraphQL on ASP.NET Core
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