Query arguments in GraphQL - Cheat Sheet & Quick Revision

Recall & Review

beginner

What are query arguments in GraphQL?

Query arguments are values you pass to a GraphQL query to filter or customize the data you want to get back.

beginner

How do you define an argument in a GraphQL query?

You add the argument inside parentheses after the field name, like user(id: 5), where id is the argument name and 5 is the value.

beginner

Why use query arguments in GraphQL?

They let you ask for specific data, like one user instead of all users, making your query faster and results smaller.

intermediate

What is the difference between query arguments and variables in GraphQL?

Arguments are values written directly in the query, while variables let you pass values separately, making queries reusable and cleaner.

beginner

Show an example of a GraphQL query with an argument to get a user by ID.

Example:

query {
  user(id: 3) {
    name
    email
  }
}

In GraphQL, where do you put query arguments?

A Before the query keyword

B Inside curly braces after the query keyword

C At the end of the query string

D Inside parentheses after the field name

Query arguments go inside parentheses right after the field name, like user(id: 1).

What is the main benefit of using query arguments?

A To add comments inside queries

B To get specific data instead of everything

C To change the query language

D To make queries longer

Query arguments help you get only the data you want, making queries efficient.

Which of these is a valid GraphQL query with an argument?

A query { user { name(id: 10) } }

B query { user[id=10] { name } }

C query { user(id: 10) { name } }

D query { user { id=10, name } }

Arguments use parentheses after the field name, like user(id: 10).

How do variables relate to query arguments in GraphQL?

A Variables let you pass argument values separately from the query

B Variables replace arguments completely

C Variables are only for mutations

D Variables are used to name queries

Variables allow passing argument values outside the query text, making queries reusable.

If you want to get a user by ID using a query argument, which is correct?

A user(id: 5) { name }

B user { id: 5, name }

C user[id=5] { name }

D user { name(id: 5) }

Arguments go inside parentheses after the field name: user(id: 5).

Explain what query arguments are in GraphQL and why they are useful.

Think about how you ask for only what you want in a request.

Describe the difference between writing arguments directly in a query and using variables for arguments.

Consider how you might reuse the same query with different values.

Practice

1. What is the purpose of query arguments in GraphQL?

easy

A. To write comments inside queries

B. To define new types in the schema

C. To specify exactly what data you want from the server

D. To create mutations for updating data

Solution

1. Step 1: Understand what query arguments do

   Query arguments allow you to tell the server exactly which data you want, like filtering or limiting results.

2. Step 2: Compare options to the purpose

   Only To specify exactly what data you want from the server describes specifying data in queries. Other options describe unrelated tasks.

3. Final Answer:

   To specify exactly what data you want from the server -> Option C

4. Quick Check:

   Query arguments = specify data [OK]

Hint: Arguments filter or limit data inside parentheses [OK]

Common Mistakes:

• Confusing arguments with schema definitions
• Thinking arguments create mutations
• Using arguments for comments

2. Which of the following is the correct syntax to pass an argument named id with value 5 to a GraphQL query field user?

easy

A. user(id: 5) { name }

B. user[id=5] { name }

C. user{id=5} { name }

D. user(id=5) { name }

Solution

1. Step 1: Recall GraphQL argument syntax

   Arguments go inside parentheses after the field name, with colon separating name and value.

2. Step 2: Check each option's syntax

   user(id: 5) { name } uses parentheses and colon correctly. Options B and C use brackets or braces incorrectly. user(id=5) { name } uses equals sign instead of colon.

3. Final Answer:

   user(id: 5) { name } -> Option A

4. Quick Check:

   Arguments use (name: value) syntax [OK]

Hint: Use parentheses and colon for arguments (name: value) [OK]

Common Mistakes:

• Using square brackets instead of parentheses
• Using equals sign instead of colon
• Placing arguments inside braces

3. Given the query { books(limit: 2) { title } } and a database with books titled 'A', 'B', 'C', what will the query return?

medium

A. [{ title: 'A' }, { title: 'B' }, { title: 'C' }]

B. [] (empty list)

C. Error: 'limit' is not a valid argument

D. [{ title: 'A' }, { title: 'B' }]

Solution

1. Step 1: Understand the limit argument

   The limit: 2 argument restricts the number of returned books to 2.

2. Step 2: Predict the returned data

   From books 'A', 'B', 'C', only the first two 'A' and 'B' will be returned.

3. Final Answer:

   [{ title: 'A' }, { title: 'B' }] -> Option D

4. Quick Check:

   limit: 2 returns 2 items [OK]

Hint: Limit argument restricts number of results [OK]

Common Mistakes:

• Assuming all items return ignoring limit
• Thinking limit causes error
• Expecting empty list when data exists

4. Identify the error in this GraphQL query: { users(age: 'twenty') { name } } assuming age expects an integer argument.

medium

A. The field name 'users' is invalid

B. The argument value should be an integer, not a string

C. Missing curly braces around the argument

D. The query is correct and will run without errors

Solution

1. Step 1: Check argument type requirements

   The age argument expects an integer, but the query passes a string 'twenty'.

2. Step 2: Identify the type mismatch error

   Passing a string instead of an integer causes a type error in GraphQL.

3. Final Answer:

   The argument value should be an integer, not a string -> Option B

4. Quick Check:

   Argument types must match schema [OK]

Hint: Match argument types exactly as defined [OK]

Common Mistakes:

• Passing strings instead of numbers
• Assuming field names cause errors
• Thinking braces are needed around arguments

5. You want to query a list of products sorted by price descending and limited to 3 items. Which query correctly uses arguments to achieve this?

hard

A. { products(sortBy: "price_desc", limit: 3) { name price } }

B. { products(limit: 3, order: "desc") { name price } }

C. { products(sort: price, limit: 3) { name price } }

D. { products(limit: 3, sortBy: "desc_price") { name price } }

Solution

1. Step 1: Identify correct argument names and values

   The argument sortBy with value "price_desc" clearly indicates sorting by price descending. The limit argument limits results to 3.

2. Step 2: Evaluate each option's correctness

   { products(sortBy: "price_desc", limit: 3) { name price } } uses both arguments correctly. { products(limit: 3, order: "desc") { name price } } uses 'order' which may be invalid. { products(sort: price, limit: 3) { name price } } uses 'sort' without quotes and no direction. { products(limit: 3, sortBy: "desc_price") { name price } } uses 'desc_price' which is not standard.

3. Final Answer:

   { products(sortBy: "price_desc", limit: 3) { name price } } -> Option A

4. Quick Check:

   Use correct argument names and values [OK]

Hint: Use exact argument names and values from schema [OK]

Common Mistakes:

• Using wrong argument names like 'order' or 'sort'
• Passing unquoted values for strings
• Mixing argument order incorrectly