# Variables and Jinja in SQL

> Insert run dates and pipeline variables into SQL assets with Jinja, and check the rendered query before it runs.

SQL assets can use Jinja to insert values that change between runs, such as the start of the data window, or pipeline variables that several assets share. Renart renders the template for the selected window and environment, and completion, hovers and type checking work on the rendered SQL.

![A SQL asset filtering on '{{ start\_date }}'; the hover shows the Jinja expression and its rendered date, which also appears after the expression in the editor](https://getrenart.com/docs-media/jinja-variables.webp)

## Insert a run value

1. In the SQL editor, type the braces where the value belongs, for example `WHERE order_date >= '{{ }}'`.
2. With the cursor inside the braces, open completion (**Ctrl+Space**) and choose a value.
3. Hover the expression to see what it renders to. The rendered value also appears after the expression in the editor.

```sql
SELECT
    order_date,
    SUM(total_amount) AS revenue
FROM staging.orders
WHERE order_date >= '{{ start_date }}'
GROUP BY order_date
```

Built-in values:

| Value                              | Meaning                        |
| ---------------------------------- | ------------------------------ |
| `start_date`, `end_date`           | Run start and end date         |
| `start_datetime`, `end_datetime`   | Run start and end datetime     |
| `start_timestamp`, `end_timestamp` | Run start and end timestamp    |
| `execution_date`                   | Run execution date             |
| `full_refresh`                     | Whether this is a full refresh |
| `pipeline`                         | Current pipeline name          |
| `run_id`                           | Current run ID                 |
| `this`                             | Current asset name             |
| `var`                              | Pipeline variables             |

Values follow the window selected next to the environment in the top bar. A scheduled run renders the same template for its own window.

## Share a value with pipeline variables

1. In the Explorer, open **Pipeline settings**, then **Variables**.
2. Choose **Add variable** and enter a name, a type and a default value.
3. Choose **Save changes**.
4. Use the variable as `{{ var.name }}`. Inside the braces, completion lists the pipeline’s variables with their types.

Pipeline variables are saved with the pipeline and can be referenced from SQL, YAML and Python assets.

## Check the rendered query

Open **Render** in the results panel to see the compiled SQL, the run window and the planned operations without executing anything. If a template cannot be rendered, **Review run** reports it as a blocker, so fix the expression before running.

## Related

- [The asset editor](https://getrenart.com/docs/editing-assets/asset-editor.md): the editor, results panel and workbench.
- [Catch errors with type checking](https://getrenart.com/docs/editing-assets/type-checking.md): checks also run on rendered templates.
- [Python assets](https://getrenart.com/docs/asset-types/python-assets.md): read the run window and pipeline variables from Python.