---
title: MySQL Custom Queries
description: Datadog, the leading service for cloud-scale monitoring.
breadcrumbs: Docs > Integrations > Integration Guides > MySQL Custom Queries
---

# MySQL Custom Queries

The Datadog MySQL integration can collect metrics from custom queries.

## Configuration{% #configuration %}

Follow the configuration details in the [MySQL conf.yaml](https://github.com/DataDog/integrations-core/blob/master/mysql/datadog_checks/mysql/data/conf.yaml.example) file. Additional items of consideration are below.

### Qualify your database{% #qualify-your-database %}

When adding a custom query to the [MySQL conf.yaml](https://github.com/DataDog/integrations-core/blob/master/mysql/datadog_checks/mysql/data/conf.yaml.example), each table referenced must have the database qualified. This is done by prepending the table with its database name in the following format:

```sql
SELECT * FROM database_name.table_name WHERE...
```

If you omit the database name, the Agent fails to run the query with the error: `No database selected`.

### Name your metric{% #name-your-metric %}

The names applied to your query metrics are taken as provided (there are no prepends). For example, your metric name could be: `myapp.custom_query.test`.

### Collection frequency{% #collection-frequency %}

By default your metrics are collected by the MySQL check every 15-20 seconds. To query these metrics at a different frequency, reduce the frequency of the entire MySQL check (this affects the frequency of your general `mysql.*` metrics), or run a custom scheduled CRON script to submit metrics with the [API](https://docs.datadoghq.com/api/) or [DogStatsD](https://docs.datadoghq.com/metrics/custom_metrics/dogstatsd_metrics_submission/).

### Number of custom queries{% #number-of-custom-queries %}

Running a large number of custom queries from the MySQL check can delay other Agent checks. If you need to collect metrics from a large number of custom MySQL queries, run a custom scheduled CRON script to submit metrics with the [API](https://docs.datadoghq.com/api/) or [DogStatsD](https://docs.datadoghq.com/metrics/custom_metrics/dogstatsd_metrics_submission/).

## Example{% #example %}

You have a database named `tester` with the table `test_table` that contains the following data:

```text
col_1 | col_2 | col_3
---------------------
1     | a     | a
2     | b     | b
3     | c     | c
```

Adding the following custom query to your MySQL `conf.yaml` collects the metric `myapp.custom_query.test.b` with a value of `2`.

```yaml
    custom_queries:
      - query: SELECT col_1 FROM tester.test_table WHERE col_2 = 'b'
        columns:
        - name: myapp.custom_query.test.b
          type: gauge
        tags:
        - tester:mysql
```

## Further Reading{% #further-reading %}

- [Datadog MySQL integration](https://docs.datadoghq.com/integrations/mysql)