Understanding how to add and modify fields in Sanity documents

The query I got is not equal to the schema I created, it lacks "grade".

export default {

    name: 'user',
    title: 'User',
    type:'document',
    fields:[
        {
            name:"userName",
            title:"UserName",
            type:"string"
        },
        {
            name:'image',
            title: 'Image' ,
            type:'string'
        },
        {
            name:"admin",
            title:"Admin",
            type:"boolean",
            initialValue: false,
        },
        {
            name:"grade",
            title:"Grade",
            type:"string",
            initialValue: "somethingpls"
        }
    ],
}

Then here's the query I wrote:

When I console.log the query, it gives me this:

The result in the console doesn't include grade

why?

oh I see. Then would the grade attribute be created as well?

at least it should give grade: undefined

No, because the Content Lake is schemaless, so grade doesn't exist until you set it.

How do I affect the existing document in client?

Also, in the backend, it does have grade

The studio has grade but the printed out user doesn't have grade

Even after I gave a value to the grade manually, it still doesn't have it, so I am confused, is the process of fetching wrong, or the document is wrong

As I said, the backend it schemaless. That field only exists in the Studio UI until you set it.
If you specifically said in your query:

It
would give you a

null

for grade.
To retroactive apply information to existing documents, you have to run a
mutation either via the API or a client .

One thing to check if you have set the field and it's not coming through on your frontend is whether or not you've published the change.

Lemme try publishing it again

Oh you are right!

got the grade now

man

Thx, it's solved, now I just need to learn how to change it

Come back if you're having trouble with the mutation. It's tricky when you first encounter it!

Cool, thankx!

Hey, I have trouble reading the doc of mutation. I don't know where this example is supposed to belong to:

I want every user able to set their grade in frontend

I know how to write a query like this, but I don't know where that example should be put at. It looks more like a console command.

Ah, if you're writing to your dataset from the frontend you'll need to use one of the clients. What frontend framework are you using?

I am using react. If I can do client.create, then I can also do client.patch right?

I did the client.create here

If I want to change value instead of creating, I can just use client.patch right? I didn't know this function before

Exactly. You'll want to use

patch

. If you look at this example:
First, you give it the document ID you want to patch, then you set and object that matches the fields in your schema you want to change, then you commit those changes.

lol dude, it worked! Thank you

as simple as this

one time success no debug lol