{planLabel}
{displayName}{" "}
{defaultDescription} {description}
;
};
SQL in GrowthBook is first run through a templating engine (Handlebars) to allow for dynamic SQL generation. This allows for several advanced use cases, outlined below.
## Date Filters
GrowthBook always includes a date filter in the SQL queries it generates, but because the queries are complex with multiple nested subqueries, database engines are not always able to fully take advantage of these filters for optimization.
If you have a date-partitioned table, you can use template variables within the SQL you enter in GrowthBook to provide better hints to your database. This applies to metrics, fact tables, and experiment assignment queries.
Here's an example of a simple Fact Table definition that uses template variables:
```sql theme={null}
SELECT
timestamp,
user_id,
amount
FROM purchases
WHERE
timestamp BETWEEN '{{startDate}}' AND '{{endDate}}'
```
The following variables are available:
* **startDate** - `yyyy-MM-dd HH:mm:ss` of the earliest data that needs to be included
* **startDateISO** - `yyyy-MM-dd'T'HH:mm:ss.SSS'Z'` of the startDate in ISO format
* **endDate** - `yyyy-MM-dd HH:mm:ss` of the latest data that needs to be included
* **endDateISO** - `yyyy-MM-dd'T'HH:mm:ss.SSS'Z'` of the endDate in ISO format
There is also a `date` helper you can use with the ISO variables to format the date exactly how you need it. For example `{{date endDateISO "yyyyMMdd"}}`
| code | meaning |
| ---- | --------- |
| yyyy | year |
| MM | month |
| dd | day |
| HH | hour |
| mm | minutes |
| ss | seconds |
| t | timestamp |
Here's a full example of this being used:
```sql theme={null}
SELECT
user_id as user_id,
received_at as timestamp
FROM
orders
WHERE
partition_key BETWEEN
'{{date startDateISO "yyyyMMdd"}}' AND '{{date endDateISO "yyyyMMdd"}}'
```