> For the complete documentation index, see [llms.txt](https://docs.qyrus.com/data-testing/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://docs.qyrus.com/data-testing/sql-databases/index.md).

# SQL Connectors

> Set up SQL database connectors to retrieve data for comparison or evaluation jobs. Each connector requires database credentials, connection details, and optional keys for alignment.

## Overview

SQL (Structured Query Language) connectors enable you to connect to relational databases for data validation. Whether you're using cloud-based solutions, enterprise databases, or open-source options, Data Testing supports comprehensive SQL integration.

{% hint style="info" %}
All SQL connectors support custom SQL queries, pagination controls, and advanced filtering to accommodate your specific validation needs.
{% endhint %}

***

## Available SQL Connectors

{% tabs %}
{% tab title="Cloud Data Warehouses" %}
Modern, scalable cloud-native solutions:

| Connector           | Platform    | Approach                    |
| ------------------- | ----------- | --------------------------- |
| **Amazon Redshift** | AWS         | Column-store data warehouse |
| **Snowflake**       | Multi-Cloud | Elastic cloud data platform |

[Amazon Redshift →](/data-testing/sql-databases/index/redshift.md) [Snowflake →](/data-testing/sql-databases/index/snowflake.md)
{% endtab %}

{% tab title="Enterprise Databases" %}
Industry-standard, battle-tested solutions:

| Connector                | Platform       | Type             |
| ------------------------ | -------------- | ---------------- |
| **Oracle Database**      | Multi-Platform | Enterprise RDBMS |
| **Microsoft SQL Server** | Windows/Cloud  | Enterprise RDBMS |
| **IBM DB2**              | Enterprise     | Enterprise RDBMS |

[Oracle →](/data-testing/sql-databases/index/oracle.md) [SQL Server →](/data-testing/sql-databases/index/mssql.md) [DB2 →](/data-testing/sql-databases/index/db2.md)
{% endtab %}

{% tab title="Open Source" %}
Community-driven, widely-adopted solutions:

| Connector | Platform       | Type              |
| --------- | -------------- | ----------------- |
| **MySQL** | Multi-Platform | Open-source RDBMS |

[MySQL →](/data-testing/sql-databases/index/mysql.md)
{% endtab %}
{% endtabs %}

***

## Common SQL Settings

All SQL connectors share common configuration patterns:

### Connection Parameters

| Parameter         | Description                     | Required |
| ----------------- | ------------------------------- | -------- |
| **Host/Hostname** | Database server address or IP   | ✅ Yes    |
| **Port**          | Database service port           | ✅ Yes    |
| **Database Name** | Specific database to connect to | ✅ Yes    |
| **Username**      | Authentication username         | ✅ Yes    |
| **Password**      | Authentication password         | ✅ Yes    |

### Optional Parameters

| Parameter           | Description                         |
| ------------------- | ----------------------------------- |
| **Schema**          | Specific schema within the database |
| **Connection Pool** | Connection pooling configuration    |
| **Query Timeout**   | Query execution timeout (seconds)   |
| **SSL/TLS**         | Secure connection options           |

***

## SQL Query Configuration

{% hint style="info" %}
Write your SQL queries to:

* Select specific columns you want to validate
* Filter to relevant data with WHERE clauses
* Use consistent ordering for comparisons
* Consider performance with LIMIT clauses
  {% endhint %}

### Example Query Format

```sql
SELECT 
  id,
  customer_name,
  email,
  created_at,
  status
FROM customers
WHERE created_at >= '2024-01-01'
  AND status = 'active'
ORDER BY id ASC
LIMIT 10000;
```

***

## Advanced Features

### Pagination & Limits

Enable pagination controls to handle large datasets efficiently:

* 📊 **Limit** - Restrict number of records retrieved
* 📍 **Offset** - Skip specific number of records
* 🔄 **Batch Processing** - Process data in chunks

{% hint style="success" %}
Perfect for reducing resource usage and validating data in batches.
{% endhint %}

### Alignment Keys

Specify keys for aligning data during comparison jobs:

* Use **Primary Keys** to match records across sources
* Support for **Composite Keys** (multiple columns)
* Automatic key detection available

***

## Connection Best Practices

{% hint style="warning" %}
**Security & Performance:**

1. ✅ Use dedicated read-only database users
2. ✅ Restrict database access by network/IP
3. ✅ Enable TLS/SSL for connections
4. ✅ Rotate credentials regularly
5. ✅ Monitor query performance and resource usage
6. ✅ Keep database statistics up-to-date for optimal planning
   {% endhint %}

***

## Troubleshooting Connection Issues

| Issue                 | Solution                                         |
| --------------------- | ------------------------------------------------ |
| Connection Timeout    | Check host/port, verify firewall rules           |
| Authentication Failed | Verify username/password, check user permissions |
| Query Errors          | Validate SQL syntax, check table/column names    |
| Performance Issues    | Add query limits, optimize WHERE clauses         |

***

## Quick Links

**SQL Connectors:**

* [Amazon Redshift](/data-testing/sql-databases/index/redshift.md) - AWS data warehouse
* [MySQL](/data-testing/sql-databases/index/mysql.md) - Open-source relational database
* [Microsoft SQL Server](/data-testing/sql-databases/index/mssql.md) - Enterprise SQL database
* [IBM DB2](/data-testing/sql-databases/index/db2.md) - Enterprise database system
* [Oracle Database](/data-testing/sql-databases/index/oracle.md) - Industry standard database
* [Snowflake](/data-testing/sql-databases/index/snowflake.md) - Cloud data platform

**Related Topics:**

* [Compare Jobs](/data-testing/jobs-and-workflows/index/compare-job.md)
* [Evaluate Jobs](/data-testing/jobs-and-workflows/index/evaluate-job.md)
* [Data Source Overview](/data-testing/data-sources/index.md)