SQL is good for tabular data, or information that fits neatly into rows and columns. XML is ideal for hierarchical data or data that has multiple levels of varying sizes. SQL is useful for storing and searching data. XML is useful for both conveying and formatting data.
Instead of developing a whole database, you might utilise XML. However, I would recommend that you consider the type and amount of data you want to keep, as well as your justifications for not using a database. The relational elements of a database, such as MySql or SQL, are one of the benefits of using one. The database server's ability to execute a reasonable amount of work, as well as the fact that this is a typical method of storing data in the tech world.
Nowadays, there are several alternatives to using a full-scale database, one of which is XML.
You can also store data as a JSON object if you're using Javascript, or as an array in whatever programming language, you're using. There are NoSql databases that use JSON to store data as a single large array of key => value pairs that can be nested for quite complex data structures. If you're using a framework like React, you can also use Flux or Redux to store data in a Javascript structure known as a Store.
