# Part 3: A closer look at operations and queries · A simple Chromia app with Rell and React · Learn Chromia > This lesson shows you how to change data on the Chromia blockchain platform. You write Rell operations that create users, publish posts, and manage who… Source: https://chromia.com/learn/my-news-feed/module-one/operations-queries/ A simple Chromia app with Rell and ReactLesson 10 of 27 1. [01Building a simple Chromia app with Rell, React and FT4](https://chromia.com/learn/my-news-feed/introduction/) 2. [02Project setup complete](https://chromia.com/learn/my-news-feed/setup/) Module 1: A Rell backend with FT accounts 1. [03Overview](https://chromia.com/learn/my-news-feed/module-one/) 2. [04Part 1: Designing the database schema](https://chromia.com/learn/my-news-feed/module-one/data-modeling/) 3. [05The data model](https://chromia.com/learn/my-news-feed/module-one/data-modeling/tables/) 4. [06Code the model in Rell](https://chromia.com/learn/my-news-feed/module-one/data-modeling/model/) 5. [07Part 2: Set up accounts](https://chromia.com/learn/my-news-feed/module-one/create-accounts/) 6. [08FT4 accounts configuration](https://chromia.com/learn/my-news-feed/module-one/create-accounts/install-configure-ft4/) 7. [09Authentication with FT4 accounts](https://chromia.com/learn/my-news-feed/module-one/create-accounts/authentication/) 8. [10Part 3: A closer look at operations and queries](https://chromia.com/learn/my-news-feed/module-one/operations-queries/) 9. [11Basic operations](https://chromia.com/learn/my-news-feed/module-one/operations-queries/basic-operations/) 10. [12Basic queries](https://chromia.com/learn/my-news-feed/module-one/operations-queries/write-queries/) 11. [13Part 4: Validating and verifying input](https://chromia.com/learn/my-news-feed/module-one/input-verification/) 12. [14Verify inputs](https://chromia.com/learn/my-news-feed/module-one/input-verification/input-verification/) 13. [15Run unit tests](https://chromia.com/learn/my-news-feed/module-one/input-verification/tests/) 14. [16Part 5: How the dapp project is organized](https://chromia.com/learn/my-news-feed/module-one/project-structure/) 15. [17Work with Rell modules](https://chromia.com/learn/my-news-feed/module-one/project-structure/modules/) 16. [18Add modules to your dapp](https://chromia.com/learn/my-news-feed/module-one/project-structure/incorporate-modules/) 17. [19Part 6: Sign up users with an EVM wallet](https://chromia.com/learn/my-news-feed/module-one/register-evm-accounts/) 18. [20Sign up accounts with EVM wallets](https://chromia.com/learn/my-news-feed/module-one/register-evm-accounts/register-evm-accounts/) 19. [21Test the registration](https://chromia.com/learn/my-news-feed/module-one/register-evm-accounts/test-registration/) Module 2: The React project 1. [22Overview](https://chromia.com/learn/my-news-feed/module-two/) 2. [23Set up the project](https://chromia.com/learn/my-news-feed/module-two/setup/) 3. [24Project scaffold](https://chromia.com/learn/my-news-feed/module-two/scaffold/) 4. [25Connect the client](https://chromia.com/learn/my-news-feed/module-two/connecting-the-client/) 5. [26Summary and manual testing](https://chromia.com/learn/my-news-feed/module-two/summary-and-tests/) 1. [27What is next?](https://chromia.com/learn/my-news-feed/what-next/) [Learn](https://chromia.com/learn/)[A simple Chromia app with Rell and React](https://chromia.com/learn/my-news-feed/) 10 / 27Module 1: A Rell backend with FT accountsBeginner # Part 3: A closer look at operations and queries This lesson shows you how to change data on the Chromia blockchain platform. You write Rell operations that create users, publish posts, and manage who follows whom, with a code example for each step. You also test your dapp to confirm it behaves correctly. After that, you read data back with queries. You begin with simple ones that return user details and follower counts, then build up to queries that paginate and sort results. The lesson ends with you running queries by hand through the Chromia CLI. ## In this lesson 1. [Basic operations](https://chromia.com/learn/my-news-feed/module-one/operations-queries/basic-operations/) 2. [Basic queries](https://chromia.com/learn/my-news-feed/module-one/operations-queries/write-queries/) [Begin lesson →](https://chromia.com/learn/my-news-feed/module-one/operations-queries/basic-operations/) Written for this site from Chromia’s public course. Code samples are the course’s own. [← Previous**Authentication with FT4 accounts**](https://chromia.com/learn/my-news-feed/module-one/create-accounts/authentication/)[Next →**Basic operations**](https://chromia.com/learn/my-news-feed/module-one/operations-queries/basic-operations/)