How to deal with the error

Error Cannot return null for non-nullable type

. I added a new attribute 

name!

  in the data model file and then did

prisma generate

and

prisma deploy

. When I query, it gives the above error

Hey @Suhail 👋 Could you share your datamodel and query that you are performing?

Initial data model

type User {id: ID! @id, username: string}

Then I did

prisma generate

and then

prisma deploy

I performed insertions and update queries using the API generated by prisma

prisma.updateUser

Then I updated the data model file as

type User {id: ID! @id, username: string, name: string!}

adding

name

attribute and making it

!

. Now when I perform

prisma.user

(i.e. get query), I get this error @Ryan

You have added a non-nullable field

name

. Due to this the previous records will have the

name

field set to

null

. Could you try adding non-null values to name for all the current records in the database and then query again?

Yes, that will work. But is there any other way out? I am working with a Mongo database and if this happens in prod, I will have to update all the documents in a collection @Ryan

You would need to add a nullable field then like:

name: String

If you add a non-null field, then you would always need to update the previous records before performing the migrations.

Alright. Is there a way with

prisma

to do automatic migrations?

Could you explain what automatic would be in this case? Do you want to perform any operation before/after migrations?

Yes. Considering the above case. Would there be a way where I could add non-null [empty string] values before doing

prisma deploy

?

It would have to be done in the following steps: 1. Create a field first that is nullable:

name: String

and run

prisma deploy

2. Seed the data via a script (either js/ts) file into all current records in the database 3. Change the field to non-nullable

name: String!

and again run

prisma deploy

Currently you would have to follow these steps to add a non-nullable field with already present records

Okay