[Solved] Given this input type:input LocationInput { street: String!, city: String! }and mutation:mutation createLocation($loc: LocationInput!) { addLocation(location:... What is the most likely cause? | GraphQL

GraphQL - Mutations

Given this input type:

input LocationInput { street: String!, city: String! }

and mutation:

mutation createLocation($loc: LocationInput!) { addLocation(location: $loc) { id } }

You receive an error about missing required fields when calling the mutation with variables. What is the most likely cause?

AThe mutation is missing a return type for the <code>addLocation</code> field.

BThe input type fields are optional but the mutation requires them to be non-null.

CThe variable name in the mutation call does not match the expected argument name.

DGraphQL does not support nested input types in mutations.

Step-by-Step Solution

Solution:

Step 1: Check variable names
The mutation expects a variable named $loc of type LocationInput!.
Step 2: Verify mutation call
If the mutation call uses a different variable name or argument name (e.g., $location instead of $loc), GraphQL will report missing required fields.
Step 3: Confirm input fields
Since fields are non-null, they must be provided, but the error is usually due to mismatched variable names.
Final Answer:
The variable name in the mutation call does not match the expected argument name. is the most likely cause.
Quick Check:
Variable names must match mutation argument names exactly. [OK]

Quick Trick: Match variable names exactly in mutation calls [OK]

Common Mistakes:

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