How to Pass Arguments in GraphQL Query: Simple Guide

In GraphQL, you pass arguments by specifying them inside parentheses after the field name in your query using argumentName: value syntax. These arguments allow you to filter or customize the data returned by the query.

Syntax

To pass arguments in a GraphQL query, write the field name followed by parentheses containing argumentName: value pairs. Values can be strings (in quotes), numbers, booleans, or variables. This tells the server what specific data you want.

• Field name: The data you want to fetch.
• Arguments: Parameters inside parentheses to filter or customize the data.
• Values: The actual data you pass, like a string or number.

graphql

query GetUser {
  user(id: "123") {
    name
    email
  }
}

Example

This example shows a query that fetches a user by their id argument. The server returns the user's name and email. This demonstrates how to pass a string argument to get specific data.

graphql

query GetUserById {
  user(id: "abc123") {
    name
    email
  }
}

Output

{
  "data": {
    "user": {
      "name": "Alice",
      "email": "[e-mail]"
    }
  }
}

Common Pitfalls

Common mistakes when passing arguments include:

• Forgetting to put string values in quotes, which causes syntax errors.
• Using incorrect argument names that the server does not recognize.
• Passing variables without declaring them in the query.

Always check the schema for correct argument names and types.

graphql

query WrongQuery {
  user(id: abc123) {  # Missing quotes around string value
    name
  }
}

# Corrected version:
query CorrectQuery {
  user(id: "abc123") {
    name
  }
}

Quick Reference

Concept	Description	Example
Argument syntax	Use parentheses after field with name:value pairs	user(id: "123")
String values	Must be in double quotes	"abc123"
Number values	Use numbers directly	limit: 10
Boolean values	Use true or false	active: true
Variables	Declare and pass with $ prefix	user(id: $userId)

Key Takeaways

Pass arguments in GraphQL by adding parentheses with name:value pairs after the field.

Always put string argument values in double quotes to avoid syntax errors.

Check the GraphQL schema for correct argument names and types before querying.

Use variables for dynamic arguments by declaring them in the query.

Common errors include missing quotes and wrong argument names.