What is required for working with aggregates in OutSystems?

Working with aggregates in OutSystems requires SQL knowledge because aggregates are essentially a way to retrieve and manipulate data from the database using visual queries that resemble SQL operations. Understanding SQL allows developers to grasp how data is structured, relate tables, and apply filtering or sorting in aggregates effectively.

In OutSystems, aggregates utilize SQL concepts to define how data is fetched and processed, such as using joins, distinguishing between different data types, and managing relationships. This foundational knowledge enables developers to create efficient data queries that align with the application's requirements.

The other options relate to different aspects of web development. Java is commonly associated with backend logic and server-side programming; HTML is used for structuring and displaying content in web applications, and PHP is another server-side scripting language, but none of these are directly pertinent to working with data aggregates in OutSystems.