How can you use queries to support data visualization?

If possible, get your hands on a data model, data schema or metadata (technical &/or operational &/or business). This will enable you to know what data is in which store. From there you can "shop" for the data you want at the appropriate "store" with queries.

One can use them (queries, see main title) by sending them to a database where one suspects the data to be. It's recommendable to know a little bit about technical metadata and use this information properly to create syntactically correct queries. Some of these requirements will however soon be less strict. By using LLMs one can formulate queries in natural language and together with some agents one can speak in natural language to a database. SAP will soon offer "Just ask" to allows interaction with data in a syntactically less strict way. I haven't checked this yet, but I guess that the other big providers will offer similar functionality already or soon.

Leveraging queries to construct views and materialized views provides a structured and efficient approach to preparing data for visualization, optimizing performance, and ensuring that visualizations align with business objectives.

Limit the most unneeded data as quickly as possible. Temp tables / CTE's are great friends for this. Try to keep WHERE statements simple and add limits to joins and/or temp tables/CTE's.

Queries are used to extract data from the source systems and build visualizations. To provide a better user experience, improving the dashboard with filters and parameters could enhance interactivity. Interactivity gives the user an option to choose a date range, select particular categories, and filter by KPI to view the dashboard in different formats. In tableau, parameters can be created with calculated fields to support filtering options for the user.

In Business Intelligence (BI), utilizing queries effectively supports data visualization by extracting relevant information from databases. Constructing well-crafted SQL queries allows you to retrieve specific data sets that align with your visualization objectives. Filter and aggregate data through queries to provide the necessary inputs for charts, graphs, or dashboards. Ensure the queries are optimized for performance to enhance the speed and responsiveness of your visualizations. By mastering query language and understanding database structures, you empower yourself to create dynamic and insightful visual representations that accurately convey the story within your data.