GraphQL Tutorial #9 - The Resolve Function

Hey all, in this GraphQL tutorial I'll show you how we can use the resolve function to go out and actually grab our data for the GraphQL server to return to the front-end.

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[Ladyhoat]

//Dummy data for lazy ones :)

const books = [
{name: 'Name of the Wind', genre: 'Fantasy', id: '1'},
{name: 'The Final Empire', genre: 'Fantasy', id: '2'},
{name: 'The Long Earth', genre: 'Sci-Fi', id: '3'}
]

[haciendadad]

You can use es6 instead of lodash like so: return book.find(book => book.id == args.id)

[incarnateTheGreat]

Very cool, but why not encourage using ES6 Find instead of downloading lodash and installing it just to do the same thing?

[jesseallaway]

Thank you for these tutorials, they're just the right amount of info!

[garybarnes]

Finally ! A course that has enabled me to successfully set up a Graphql server - Thanks !!

[moulcode]

hey, bro, I'm from Morocco & I'm so glad to watching ur videos are very helpful ; I have one question about resolve function : what's the needed of parent & why u passed in resolve function ?? thank u :)

[mukeshjaiswal]

For those looking for :
// dummy data
var books = [
{ name: 'Name of the Wind', genre: 'Fantasy', id: '1' },
{ name: 'The Final Empire', genre: 'Fantasy', id: '2' },
{ name: 'The Long Earth', genre: 'Sci-Fi', id: '3' },
];

[MobiusCoin]

We're good to use the filter method to return the book right?

[baibhavgautam]

Why did we use lodash instead of `return books.find(book => book.id === args.id); `

[gglandshomeunixorg]

It's a beauty! Je bois vos paroles ;)

[alexgeorge]

If you have got errors like graphqlTTP is not function, try destructure it from express-graphql

[Ladyhoat]

Hey Mr. Ninja! One beginner question for ya. I am wondering why I can't use javascript filter loop instead of lodash :)

[DineshChaturvedi-tp]

I am getting this error Could not find name 'book'. Did you mean 'books'?ts(2570). Surprised nobody is getting this error. Also GitHub Does not even have the below code.
book(id:"2"){
name
genre
}

I have very little understanding for nodejs right now, I have worked in JavaScript way before these things arrived.

[nathanie]

Why use lodash?

books.find(({ id: bookID}) => bookID === id)

[knowledgeforsuccess]

"loadash" is no longer supported and has been deprecated,
instead use "npm i lodash"

[stanleylouis]

resolve(parent, args) {
// code to get data from db / other source
// return _.find(books, { id: args.id });
// without lodash
return books.find(book => book.id === args.id);
}

[terrybabb]

Why require the ID, a randomly generated string, to look up a db item?? Nobody explains that. I would rather look up by title or author or some other human-friendly parameter!

[harshalrajput]

I followed all the steps as you told in this series, but the localhost is not responding, I think I made mistake is schema, can you please help me the code is in github repository

[databasenomad]

Hi, I'm facing a problem - the query in graphiql gives an error: "return_ is not defined" - I can't find the reason - googled several times but find nothing // this series is awesome, thanks

[yashuagrawal]

You are just adding packages like nothing. It just complicates everything instead of understanding.