> For the complete documentation index, see [llms.txt](https://docs.snomed.org/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://docs.snomed.org/snomed-ct-practical-guides/snomed-ct-data-analytics-guide/9-database-queries.md).

# Database Queries

Practically all analytical processes are driven by database queries. A database query is a machine readable question presented to a database in a predefined language.

Unlike other code systems, which either have no hierarchy or a hierarchy that is fully represented within the code (e.g. H65.9), just retrieving the SNOMED CT codes recorded in a patient record does not fully utilize the analytics capabilities of SNOMED CT. To get the most benefit from using SNOMED CT in patient records, one must be able to not only query the records themselves, but also query SNOMED CT.

In this section, we describe how record and terminology queries can work together to perform powerful queries over SNOMED CT enabled data.

***

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# Agent Instructions
This documentation is published with GitBook. GitBook is the documentation platform designed so that both humans and AI agents can read, navigate, and reason over technical content effectively. Learn more at gitbook.com.

## Querying This Documentation
If you need additional information that is not directly available in this page, you can query the documentation dynamically by asking a question.

Perform an HTTP GET request on the current page URL with the `ask` query parameter, and the optional `goal` query parameter:

```
GET https://docs.snomed.org/snomed-ct-practical-guides/snomed-ct-data-analytics-guide/9-database-queries.md?ask=<question>&goal=<endgoal>
```

`ask` is the immediate question: it should be specific, self-contained, and written in natural language.
`goal` is optional and describes the broader end goal you are ultimately trying to accomplish on behalf of the user. GitBook uses it to tailor the answer towards what is most useful for that goal.

The response will contain a direct answer to the question and relevant excerpts and sources from the documentation.

Use this mechanism when the answer is not explicitly present in the current page, you need clarification or additional context, or you want to retrieve related documentation sections.