Prisma

```
mutation {
  updateEmployee(
    data: {
      title: ""
    }
    where: {
      title: null
    }
  ) {
    id
    name
  }
}
```

Can’t find again where I found this once, but using a `where: { field: null }`should be the valid way of doing this

```
"Argument 'where' expected type 'EmployeeWhereUniqueInput!' but got: {title: null}. Reason: 'title' Field 'title' is not defined in the input type 'EmployeeWhereUniqueInput'. (line 2, column 44):\n  updateEmployee(data: {title: \"\"}, where: {title: null}) {\n                                           ^\n (line 2, column 45):\n  updateEmployee(data: {title: \"\"}, where: {title: null}) {\n 
```

Apparently it works when I try the `id` field, but that seems kinda pointless :stuck_out_tongue:

Ah right, that’s because you first need to put your field as not required, script your migration using the above mutation, and then put it as required once all your nodes have data

I first tried to deploy the `String!` variant, but then prisma let me know that constraints would be violated. Ok fine..I wanted to try the mutation.. and here we are :stuck_out_tongue:

`Reason: 'title' Field 'title' is not defined in the input type 'EmployeeWhereUniqueInput'`: Looks like your `title` field wasn’t properly deployed to your api

is `title` a unique property on the `Employee` type?

Then you can't use it in the `where` selection for single nodes.

Maybe you meant to run `updateManyEmployees`?

Aha, I guess so then. Since there was a where clause in the `updateEmployee`, I kinda expected it to hit all rows in the table.

`updateEmployee` updates a single node, selected by a unique argument specified in `where`

`updateManyEmployee` updates an arbitrary number of nodes, selected by arbitrary conditions specified in `where`

Ahhhh, of course, silly me! Good catch <@U0RQY0KK5>!

I don't *quite* understand why there is a distinction between updating one node and updating many nodes, but oh well. This is exactly what I needed!

There are different reasons :slightly_smiling_face:

some are mentioned here: <https://www.prisma.io/docs/reference/prisma-api/concepts-utee3eiquo#batch-operations>