Error classification in GraphQL - Interactive Code Practice

Practice - 5 Tasks

1fill in blank

easy

Complete the code to define a GraphQL error type with a message field.

GraphQL

type Error { message: [1] }

Drag options to blanks, or click blank then click option'

AInt

BString!

CBoolean

DFloat

Attempts:

3 left

💡 Hint

Common Mistakes

Using Int or Boolean instead of String for error messages.

Forgetting the exclamation mark to make the field required.

The message field should be a non-nullable string to hold error messages.

2fill in blank

medium

Complete the code to define a GraphQL query that returns a list of errors.

GraphQL

type Query { errors: [[1]!]! }

Drag options to blanks, or click blank then click option'

ABoolean

BString

CError

DInt

Attempts:

3 left

💡 Hint

Common Mistakes

Using String or Int instead of the Error type.

Not marking the list or its items as non-nullable.

The query returns a non-nullable list of non-nullable Error objects.

3fill in blank

hard

Fix the error in the mutation definition to accept an error message as input.

GraphQL

type Mutation { addError(message: [1]): Error }

Drag options to blanks, or click blank then click option'

AString

BBoolean

CInt

DFloat

Attempts:

3 left

💡 Hint

Common Mistakes

Using non-string types for the message argument.

Omitting the argument type.

The message argument should be a string to accept text input.

4fill in blank

hard

Fill both blanks to define an input type for error classification with a code and message.

GraphQL

input ErrorInput { code: [1] message: [2] }

Drag options to blanks, or click blank then click option'

AInt!

BString

CString!

DBoolean

Attempts:

3 left

💡 Hint

Common Mistakes

Using nullable types when fields should be required.

Using Boolean for message instead of String.

The code is a non-nullable integer and message is a non-nullable string.

5fill in blank

hard

Fill all three blanks to define a mutation that accepts ErrorInput and returns an Error.

GraphQL

type Mutation { createError(input: [1]): [2] }

Drag options to blanks, or click blank then click option'

AErrorInput!

BError

CError!

DErrorInput

Attempts:

3 left

💡 Hint

Common Mistakes

Forgetting exclamation marks for required input or output.

Mixing input and output types.

The mutation takes a non-nullable ErrorInput and returns a non-nullable Error.

Practice

1. What is the main purpose of error classification in data science models?

easy

A. To group model mistakes into clear categories for better understanding

B. To increase the speed of the model's predictions

C. To reduce the size of the dataset

D. To improve the model's user interface

Solution

1. Step 1: Understand error classification

   Error classification means sorting mistakes into groups to see patterns.

2. Step 2: Identify the goal of grouping errors

   Grouping helps find where the model works well or needs improvement.

3. Final Answer:

   To group model mistakes into clear categories for better understanding -> Option A

4. Quick Check:

   Error classification = Group mistakes [OK]

Hint: Error classification groups mistakes to spot issues fast [OK]

Common Mistakes:

• Thinking error classification speeds up predictions
• Confusing error classification with data size reduction
• Believing it improves user interface

2. Which GraphQL query structure correctly requests error counts grouped by error type?

easy

A. query { errorCountList { errorType, total } }

B. query { errors { count type } }

C. query { errorCounts(type, count) }

D. query { errorCounts { type count } }

Solution

1. Step 1: Identify correct GraphQL syntax

   GraphQL queries use curly braces with fields inside, like { errorCounts { type count } }.

2. Step 2: Check field names and order

   query { errorCounts { type count } } uses correct field names and structure matching typical GraphQL style.

3. Final Answer:

   query { errorCounts { type count } } -> Option D

4. Quick Check:

   Correct GraphQL query = query { errorCounts { type count } } [OK]

Hint: GraphQL queries list fields inside braces in correct order [OK]

Common Mistakes:

• Using parentheses instead of braces
• Swapping field names order incorrectly
• Using wrong field names not defined in schema

3. Given this GraphQL query:

query { errorCounts { type count } }

And this response:

{ "data": { "errorCounts": [ { "type": "False Positive", "count": 5 }, { "type": "False Negative", "count": 3 } ] } }

What is the total number of errors reported?

medium

A. 3

B. 8

C. 5

D. 15

Solution

1. Step 1: Extract counts from response

   The response shows 5 False Positives and 3 False Negatives.

2. Step 2: Add the counts together

   5 + 3 = 8 total errors.

3. Final Answer:

   8 -> Option B

4. Quick Check:

   5 + 3 = 8 total errors [OK]

Hint: Add all error counts from response to get total [OK]

Common Mistakes:

• Choosing only one error type count
• Multiplying counts instead of adding
• Ignoring one of the error types

4. This GraphQL query returns an error:

query { errorCounts { type, count } }

What is the likely cause?

medium

A. Incorrect field names

B. Missing query keyword

C. Using commas between fields inside braces

D. Using parentheses instead of braces

Solution

1. Step 1: Check GraphQL field syntax

   GraphQL fields inside braces should not have commas separating them.

2. Step 2: Identify the error cause

   The query uses commas between fields, causing syntax error.

3. Final Answer:

   Using commas between fields inside braces -> Option C

4. Quick Check:

   No commas between fields in GraphQL [OK]

Hint: Remove commas between fields in GraphQL queries [OK]

Common Mistakes:

• Adding commas between fields
• Omitting the query keyword (optional but valid)
• Using wrong field names without checking schema

5. You want to find which error type has the highest count using GraphQL. Which query and approach is best?

hard

A. query { errorCounts { type count } } and then find max count in client code

B. query { maxErrorCount } to get highest count directly

C. query { errorCounts(type: "max") { count } } to filter max error

D. query { errorCounts { count } } and assume first is max

Solution

1. Step 1: Understand GraphQL query capabilities

   GraphQL typically returns lists; aggregation like max often done client-side.

2. Step 2: Choose approach to find max error count

   Query all error counts and find max in client code is standard and flexible.

3. Final Answer:

   query { errorCounts { type count } } and then find max count in client code -> Option A

4. Quick Check:

   Get all counts, find max outside GraphQL [OK]

Hint: Fetch all counts, then find max in your code [OK]

Common Mistakes:

• Expecting GraphQL to do max aggregation automatically
• Filtering by 'max' as a type which is invalid
• Assuming first item is max without checking