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REST APIs are a powerful way to interact with data and services over the internet. They use a consistent set of rules to define how data is accessed and manipulated, which makes them easy to use and understand. One of the most important aspects of REST APIs is how they handle data. Data can be passed to and from REST APIs in few ways: Query Parameters, Path Parameters, and body structure.
API parameters are customizable options that can be added to an API endpoint to modify the response. For example When making a GET request, these parameters are appended to the end of the API URL as a string. For POST requests, they are included in the request body.
Have you ever noticed how website URLs can change into a jumbled mix of characters and symbols as you interact with the site? This is because the URL is being modified with parameters that influence the content being displayed. Similarly, API parameters help us the API response to our specific needs.
In the world of API Parameters are like search filters, depending on parameters we set we get a different response each time.
REST API URLs Structure
To be able to reproduce REST API URLs in a standardized manner, REST API URLs have a common shared structure, which consists of:
Protocol: Protocols are usually in the form of HTTP or HTTPS, which specify how to communicate with the API.
Host: The host defines the server address where the API resides (e.g., api.example.com).
Path: A path defines the specific resource within the API, starting with a forward slash (e.g., /students).
Query String (optional): Query strings, which are optional, allow developers to add additional parameters that can filter or refine the resource, using key-value pairs after a question mark (e.g., /users?name=Bhavana).
Path Parameters
Path parameters limit a request to one individual resource. They help you to retrieve, update, or delete information about a specific entity. A path parameter is a variable part of the URL, in curly braces ({…}). path parameters usually denote various types of ID. They are listed in API reference documentation with the label path.
Path parameters are a powerful way to customize the behavior of a REST API. They can be used to make APIs more efficient and user-friendly.We can specify URL path parameters in either {pathParam} or :pathParam format, which will be used to generate the final URL path where the request should be executed.
For example, Here We are sending GET request with UUID as a path parameter.UUID is Dynamic path variable of the URL which is used to identify a specific resource.
UUID is placeholder which will be replaceable with actual value while making the request.
If UUID is replaced with "c589fd76-fe61-42ca-ba71-00d1ad296122" then the GET request looks like this https://demoqa.com/Account/v1/User/c589fd76-fe61-42ca-ba71-00d1ad296122
While the path and query parameters differ in many ways, they both have their boons.However, both styles should conform to the HTTP protocol for them to work. And since path parameters offer a more descriptive and distinct style, are more readable and easier to understand, they are the ideal choice when you want to identify a specific resource.
Query Parameters
API Query parameters can be defined as the optional key-value pairs that appear after the question mark in the URL. Basically, they are extensions of the URL that are utilized to help determine specific content or action based on the data being delivered. Query parameters are appended to the end of the URL, using a ‘?’. The question mark sign is used to separate path and query parameters.
If we want to add multiple query parameters, an ‘&’ sign is placed in between them to form what is known as a query string. It can feature various object types with distinct lengths such as arrays, strings, and numbers.
It critical to note that query parameters can play a pivotal role in attribution, however, it is vitally essential to ensure that the attribution strategy is in the cross-platform, and it is performing everything it can.
Here in this example ,We are sending the GET request https://demoqa.com/BookStore/v1/Book?ISBN=9781449337711 to get specific book information from the DemoQA Book Store API using its ISBN
Query parameters are useful in many ways. They can be used in filtering criteria, sorting criteria, or to represent the current page number in a paginated collection. Additionally, query parameters can be used in API requests that retrieve data. They are ideal to be passed to various methods to extend the functionality of the API.
Difference between Path and Query parameters
The difference between query and path parameters is their position in the URL. While the query parameters appear on the right side of the ‘?’ in the URL, path parameters come before the question mark sign.
The query parameters are used to sort/filter resources. On the other hand, path parameters are used to identify a specific resource or resources.
We can’t omit values in path parameters since they are part of the URL. On the other hand, query parameters are added at the end of the URL, and thus can allow omission of some values as long as the serializing standards are followed.
Query parameters have unique attributes which help to define resources in a better way. Path parameters, on the other hand, have dynamic resources, which act upon more granular objects of the resource.