Search across types in GraphQL - Interactive Code Practice

Practice - 5 Tasks

1fill in blank

easy

Complete the code to search for all items with the keyword "GraphQL".

GraphQL

query { search(text: "GraphQL") { __typename [1] } }

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

Aname

Bdescription

Cid

Dtitle

Attempts:

3 left

💡 Hint

Common Mistakes

Using title which may not exist on all types.

Using id which is less descriptive for search results.

The name field is common across types and used to identify items in search results.

2fill in blank

medium

Complete the code to include the description field in the search results.

GraphQL

query { search(text: "GraphQL") { __typename name [1] } }

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

Asummary

Bdescription

Ccontent

Ddetails

Attempts:

3 left

💡 Hint

Common Mistakes

Choosing summary which may not be defined in the schema.

Choosing content which might be too long or detailed.

The description field provides a brief explanation of the item and is useful in search results.

3fill in blank

hard

Fix the error in the fragment usage to fetch the author name.

GraphQL

query { search(text: "GraphQL") { __typename ... on Article { title author { [1] } } } }

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

Afullname

BauthorName

Cname

Dusername

Attempts:

3 left

💡 Hint

Common Mistakes

Using fullname which is not defined.

Using authorName which is not a valid field.

The name field is the correct field to get the author's name in the schema.

4fill in blank

hard

Fill both blanks to fetch the title and the published date for BlogPost type in search results.

GraphQL

query { search(text: "GraphQL") { __typename ... on BlogPost { [1] [2] } } }

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

Atitle

BpublishedDate

Cauthor

Dsummary

Attempts:

3 left

💡 Hint

Common Mistakes

Using author which is not requested here.

Using summary which is not the published date.

The title and publishedDate fields are used to show the blog post's name and when it was published.

5fill in blank

hard

Fill all three blanks to fetch the name, description, and URL for Repository type in search results.

GraphQL

query { search(text: "GraphQL") { __typename ... on Repository { [1] [2] [3] } } }

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

Aname

Bdescription

Curl

Dstars

Attempts:

3 left

💡 Hint

Common Mistakes

Using stars which is not requested here.

Mixing up the order of fields.

The name, description, and url fields provide the repository's basic info and link.

Practice

1. What does the __typename field do in a GraphQL query when searching across types?

easy

A. It tells you the type of each returned object in the result.

B. It filters the results to only one type.

C. It sorts the results alphabetically.

D. It limits the number of results returned.

Solution

1. Step 1: Understand the role of __typename

   The __typename field returns the name of the type of each object in the query result.

2. Step 2: Differentiate from other options

   It does not filter, sort, or limit results; it only identifies the type.

3. Final Answer:

   It tells you the type of each returned object in the result. -> Option A

4. Quick Check:

   __typename shows object type [OK]

Hint: Remember: __typename reveals object type, not filters or limits [OK]

Common Mistakes:

• Thinking __typename filters results
• Assuming it sorts or limits data
• Confusing it with field selection

2. Which of the following is the correct syntax to query two different types, Book and Author, in one GraphQL query using fragments?

easy

A. query { search { ... on Book { title } ... on Author { name } } }

B. query { search { Book { title } Author { name } } }

C. query { search { title, name } }

D. query { search { ...Book { title } ...Author { name } } }

Solution

1. Step 1: Recognize fragment syntax for multiple types

   Fragments use ... on TypeName { fields } to specify fields for each type.

2. Step 2: Check each option's syntax

   query { search { ... on Book { title } ... on Author { name } } } correctly uses inline fragments for Book and Author. Options B, C, and D have invalid syntax.

3. Final Answer:

   query { search { ... on Book { title } ... on Author { name } } } -> Option A

4. Quick Check:

   Fragments use ... on Type [OK]

Hint: Use ... on Type for each type's fields [OK]

Common Mistakes:

• Using type names as fields directly
• Omitting 'on' keyword in fragments
• Trying to list fields without fragments

3. Given this GraphQL query:

query { search { __typename ... on Book { title author } ... on Author { name booksCount } } }

What will be the output if the search returns one Book and one Author?

medium

A. [{ "title": "1984", "author": "Orwell" }, { "name": "Orwell", "booksCount": 5 }]

B. [{ "__typename": "Book", "title": "1984", "author": "Orwell" }, { "__typename": "Author", "name": "Orwell", "booksCount": 5 }]

C. [{ "__typename": "Book", "name": "1984", "author": "Orwell" }, { "__typename": "Author", "title": "Orwell", "booksCount": 5 }]

D. Error: Cannot query field 'booksCount' on type 'Author'

Solution

1. Step 1: Understand the query structure

   The query requests __typename and fields specific to Book and Author types.

2. Step 2: Match output to query

   The output includes type names and requested fields correctly matched to each object.

3. Final Answer:

   [{ "__typename": "Book", "title": "1984", "author": "Orwell" }, { "__typename": "Author", "name": "Orwell", "booksCount": 5 }] -> Option B

4. Quick Check:

   Output matches requested fields and types [OK]

Hint: Look for __typename and matching fields in output [OK]

Common Mistakes:

• Ignoring __typename in output
• Mixing fields between types
• Assuming syntax errors without cause

4. Identify the error in this GraphQL query that searches across types:

query { search { ... on Book { title author } ... on Author { name booksCount } } }

Assuming booksCount is not a valid field on Author type.

medium

A. The query will ignore the Author fragment entirely.

B. The query will succeed but return null for booksCount.

C. The query will fail because booksCount is not a valid field on Author.

D. The query syntax is invalid due to missing commas.

Solution

1. Step 1: Check field validity on types

   Since booksCount is not defined on Author, the query is invalid.

2. Step 2: Understand GraphQL error handling

   GraphQL returns an error and fails the query if a requested field does not exist on the type.

3. Final Answer:

   The query will fail because booksCount is not a valid field on Author. -> Option C

4. Quick Check:

   Invalid field causes query failure [OK]

Hint: Check if all fields exist on their types before querying [OK]

Common Mistakes:

• Assuming invalid fields return null
• Ignoring GraphQL schema validation errors
• Thinking commas are required between fragments

5. You want to search across three types: Book, Author, and Publisher. Each type has a field name, but Book also has pages, Author has birthYear, and Publisher has location. Which query correctly fetches the name for all types and their specific fields?

hard

A. query { search { ...Book { name pages } ...Author { name birthYear } ...Publisher { name location } } }

B. query { search { name pages birthYear location } }

C. query { search { __typename { name } ... on Book { pages } ... on Author { birthYear } ... on Publisher { location } } }

D. query { search { __typename ... on Book { name pages } ... on Author { name birthYear } ... on Publisher { name location } } }

Solution

1. Step 1: Use __typename to identify each type

   This helps distinguish which object is which type in the results.

2. Step 2: Use inline fragments with ... on Type syntax

   Each fragment fetches the common name and the type-specific fields.

3. Step 3: Verify syntax correctness

   query { search { __typename ... on Book { name pages } ... on Author { name birthYear } ... on Publisher { name location } } } correctly uses fragments and includes __typename. Other options have syntax errors or missing fragments.

4. Final Answer:

   query { search { __typename ... on Book { name pages } ... on Author { name birthYear } ... on Publisher { name location } } } -> Option D

5. Quick Check:

   Fragments + __typename fetch all fields correctly [OK]

Hint: Use __typename and fragments for each type's fields [OK]

Common Mistakes:

• Listing all fields without fragments
• Omitting __typename for type identification
• Incorrect fragment syntax without 'on'