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

# Tool Execution

> Execute database tools directly from your browser

Run pre-defined SQL statements through a constrained form interface, with URL query parameters to prefill fields for bookmarking and sharing.

## execute\_sql Tools

For `execute_sql` tools, you get a full SQL editor with syntax highlighting.

![execute-sql](https://raw.githubusercontent.com/bytebase/dbhub/main/docs/images/workbench/execute-sql.webp)

| Parameter | Description                           | Example                                       |
| --------- | ------------------------------------- | --------------------------------------------- |
| `sql`     | Prefills the SQL editor (URL encoded) | `?sql=SELECT%20*%20FROM%20users%20LIMIT%2010` |

## Custom Tools

Custom tools provide a **constrained interface** that limits users to running pre-defined SQL statements. Instead of writing arbitrary SQL, users fill in a parameter form—reducing errors and enforcing safe query patterns.

![custom-tool](https://raw.githubusercontent.com/bytebase/dbhub/main/docs/images/workbench/custom-tool.webp)

Example configuration in `dbhub.toml`:

```toml dbhub.toml theme={null}
[[tools]]
name = "delete_employee_salaries"
description = "Delete salary records for a specific employee"
source = "local_pg"
readonly = false  # Explicitly allow DELETE operations
statement = "DELETE FROM salary WHERE emp_no = $1"

[[tools.parameters]]
name = "emp_no"
type = "integer"
description = "Employee number"
required = true
```

In the Workbench, this renders as a form with a single input. The generated SQL is shown as a read-only preview before execution.

| Parameter      | Description                                                       | Example         |
| -------------- | ----------------------------------------------------------------- | --------------- |
| `{param_name}` | Prefills the form field matching the parameter name (URL encoded) | `?emp_no=10001` |