> ## Documentation Index
> Fetch the complete documentation index at: https://docs.querybear.com/llms.txt
> Use this file to discover all available pages before exploring further.

# Schema Detection

> QueryBear auto-detects every table, column, and relationship the moment you connect a database — so your AI writes accurate SQL instead of hallucinating column names.

The single biggest reason AI-generated SQL fails is that the model guesses at your schema. QueryBear removes the guessing: the moment you connect a database, it introspects the full structure and exposes it to your AI clients through the `get_schema` tool.

## What gets detected

On connect, QueryBear scans:

* **Tables and views** — including materialized views.
* **Columns** — names, data types, nullability.
* **Relationships** — foreign keys, so the AI knows how to join correctly.
* **Indexes** — useful context for the AI to write efficient queries.

```
✓ Found 24 tables, 186 columns, 12 foreign keys
  users           14 columns
  orders          11 columns
  products         9 columns
  …
✓ 12 foreign keys mapped
✓ Schema cached and ready for queries
```

## How the AI uses it

When an AI client needs to write a query, it calls `get_schema` first. QueryBear returns the structure of your **allow-listed** tables, with **blocked columns stripped out**. The AI then writes SQL grounded in the real schema — correct table names, correct column names, correct joins.

This is why the recommended workflow is always *"call get\_schema, then write the query."* It dramatically improves accuracy.

## Caching and refresh

The schema is cached so repeated `get_schema` calls are fast. When your database structure changes (a migration adds a column), refresh the schema from the dashboard or let QueryBear pick it up on the next scan. Newly added tables remain invisible until you add them to the [allow-list](/features/access-control) — schema detection never silently widens access.

## Respects your access rules

Schema detection and [access control](/features/access-control) work together: the AI only ever sees the schema of tables you've enabled, minus any blocked columns. Detection gives the AI *enough* context to be accurate, never more than you've allowed.

## Related

* [Access control](/features/access-control) — scope which schema the AI sees
* [Custom context](/features/custom-context) — enrich the schema with descriptions