Update README.md

Author: MaxineXiong

README.md

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 [![GitHub](https://badgen.net/badge/icon/GitHub?icon=github&color=black&label)](https://github.com/MaxineXiong)
 [![License: MIT](https://img.shields.io/badge/License-MIT-yellow.svg)](https://opensource.org/licenses/MIT)
 [![MySQL](https://img.shields.io/badge/MySQL-4479A1?logo=MySQL&logoColor=white)](https://www.mysql.com/)
+
+<br/>
+
+This repository features my solutions to the following [LeetCode Database Problems](https://leetcode.com/problemset/database/) that I consider challenging:
+- [603](https://leetcode.com/problems/consecutive-available-seats/)
+- [1098](https://leetcode.com/problems/unpopular-books/)
+- [1164](https://leetcode.com/problems/product-price-at-a-given-date/)
+- [1270](https://leetcode.com/problems/all-people-report-to-the-given-manager/)
+- [1321](https://leetcode.com/problems/restaurant-growth/)
+- [1384](https://leetcode.com/problems/total-sales-amount-by-year/)
+- [1393](https://leetcode.com/problems/capital-gainloss/)
+- [1484](https://leetcode.com/problems/group-sold-products-by-the-date/)
+- [1517](https://leetcode.com/problems/find-users-with-valid-e-mails/)
+
+Each solution is organized in separate folders, named according to the LeetCode problem number. They are aimed at showcasing my expertise in SQL querying, database manipulation, and problem-solving skills.
+
+## Usage
+
+This repository is intended to be used as a reference for SQL learners or as a comparison for those who want to validate their own solutions. Feel free to explore the files and examine the queries to deepen your understanding of SQL concepts.
+
+If you're using these solutions as a learning resource, it's recommended to attempt the exercises on **LeetCode** first before referring to the solutions. Understanding the problem-solving process and developing your own solutions is crucial for gaining proficiency in SQL.
+
+## License
+
+This project is licensed under the [MIT License](https://choosealicense.com/licenses/mit/). Feel free to use, modify, and distribute the code in this repository.