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

# Activate a SQL data connector

> Connect external SQL databases to automatically sync data into your Mangrove project.

## Connector Overview

Mangrove offers pre-built data connectors for common database systems. Once activated, connectors automatically sync data from your external systems into your project.

* The connectors authenticate and fetch data from the database on a scheduled cadence. This is set to a daily schedule of 11:59pm ET; we plan on making the cadence configurable soon.
* Data is fetched from a set cursor value - this allows only the latest data to be pulled into Mangrove
* SQL queries are run to fetch the data in CSV format

### Available Connectors

* Microsoft SQL Server
* Snowflake
* Snowflake (Secure Share)

<Info>
  Don't see your database? <a href="mailto:support@mangrovesystems.com" target="_blank" rel="noopener noreferrer">Contact the Mangrove team</a>

  to discuss additional connector options.
</Info>

## Activate a Connector

<Frame>
  <img src="https://mintcdn.com/mangrovesystems-54ba4724/_Ddk75_ou7frlddn/images/Screenshot2026-03-19at8.25.59AM.png?fit=max&auto=format&n=_Ddk75_ou7frlddn&q=85&s=2d5af4821414910570d35b89275af05e" alt="Screenshot2026 03 19at8 25 59AM" width="3018" height="1708" data-path="images/Screenshot2026-03-19at8.25.59AM.png" />
</Frame>

**Before you begin**

You will need:

* Database connection details (host, port, database name)
* Database credentials (username and password)
* The event type(s) you want to transform the database data into in Mangrove

### Adding a new SQL-fetch Data Feed

<Steps>
  <Step title="Add connector credentials">
    In your project, go to **Data Inputs** > **Input Settings**. Click **Add Data Feed** and select a database connector.
  </Step>

  <Step title="Configure the SQL data connector">
    Select your database type.

    Enter your database connection details (host, port, database name, username, password), then click **Test Connection** to verify access.

    <Note>
      Mangrove connects directly to your database. Check that your firewall allows connections from Mangrove's IPs. Contact support for the current allowlist.
    </Note>
  </Step>

  <Step title="Add the SQL pre-query and query">
    Add the SQL query, and test it to preview the results. You can also add a pre-query to retrieve the right tables for selecting data.

    Ensure you have set:

    * the cursor field
    * an initial cursor value
  </Step>
</Steps>

### Writing SQL Queries

When writing your SQL query, you can reference the following variables. These variables enable dynamic  queries based on the database configuration and the SQL pre-query.

| Variable              | Description                                                                            | Example Value         |
| --------------------- | -------------------------------------------------------------------------------------- | --------------------- |
| `{{cursor_field}}`    | The name of the column used as a cursor to track sync progress                         | `last_updated`        |
| `{{cursor_value}}`    | The most recent value fetched for the cursor field (e.g. timestamp or incrementing id) | `2024-05-31T23:59:00` |
| *Pre-query variables* | Any columns returned from your configured pre-query, referenced by name                |                       |

You can reference these variables in your main SQL query using double curly braces, for example:

```sql theme={null}
SELECT * FROM {{my_table_from_prequery}}
WHERE {{cursor_field}} > '{{cursor_value}}'
  AND company_id = '{{company_id_from_prequery}}'
ORDER BY {{cursor_field}} ASC
```

## Troubleshooting

<AccordionGroup>
  <Accordion title="Connection failed">
    <ul>
      <li>Verify the credentials are correct</li>
      <li>Verify that there isn't any firewall or VPN necessary to access the database.</li>
    </ul>
  </Accordion>

  <Accordion title="No data appearing in query tests">
    <ul>
      <li>Verify the source table contains data</li>
      <li>Check that field mappings are correctly configured</li>
      <li>Ensure the database user has SELECT permissions on the mapped tables</li>
    </ul>
  </Accordion>

  <Accordion title="Duplicate data">
    <ul>
      <li>Check if multiple connectors are pointing to the same table</li>
      <li>Verify the sync schedule isn't running too frequently</li>
    </ul>
  </Accordion>
</AccordionGroup>

## Managing Connectors

You can update the credentials for the connector in the **Input Settings** > **Data Feed**, then click **Edit** beside the SQL source to modify connection details.