SQL

The sql sensor platform enables you to use values from an SQL database supported by the sqlalchemy library, to populate a sensor state (and attributes). This can be used to present statistics about Home Assistant sensors if used with the recorder integration database. It can also be used with an external data source.

This integration can be configured using both config flow and by YAML.

Configuration

To add the SQL integration to your Home Assistant instance, use this My button:

Configuration by YAML

To configure this sensor, define the sensor connection variables and a list of queries to your configuration.yaml file. A sensor will be created for each query.

To enable it, add the following lines to your configuration.yaml file (example by required fields):

# Example configuration.yaml
sql:
  - name: Sun state
    query: >
      SELECT
        states.state
      FROM
        states
        LEFT JOIN state_attributes ON (
          states.attributes_id = state_attributes.attributes_id
        )
      WHERE
        metadata_id = (
          SELECT
            metadata_id
          FROM
            states_meta
          where
            entity_id = 'sun.sun'
        )
      ORDER BY
        state_id DESC
      LIMIT
        1;
    column: "state"

Information

See supported engines for which you can connect with this integration.

The SQL integration will connect to the Home Assistant Recorder database if “Database URL” has not been specified.

There is no explicit configuration required for attributes. The integration will set all columns returned by the query as attributes.

Note that in all cases only the first row returned will be used.

Examples

In this section, you find some real-life examples of how to use this sensor.

Current state of an entity

This example shows the previously recorded state of the sensor sensor.temperature_in.

sensor:
  - platform: random
    name: Temperature in
    unit_of_measurement: "°C"

The query will look like this:

SELECT
  states.state
FROM
  states
WHERE
  metadata_id = (
    SELECT
      metadata_id
    FROM
      states_meta
    WHERE
      entity_id = 'sensor.temperature_in'
  )
ORDER BY
  state_id DESC
LIMIT
  1;

Use state as column for value.

Previous state of an entity

Based on previous example with temperature, the query to get the former state is :

SELECT
  states.state
FROM
  states
WHERE
  state_id = (
    SELECT
      states.old_state_id
    FROM
      states
    WHERE
      metadata_id = (
        SELECT
          metadata_id
        FROM
          states_meta
        WHERE
          entity_id = 'sensor.temperature_in'
      )
      AND old_state_id IS NOT NULL
    ORDER BY
      last_updated_ts DESC
    LIMIT
      1
  );

Use state as column for value.

State of an entity x time ago

If you want to extract the state of an entity from a day, hour, or minute ago, the query is:

SELECT 
  states.state
FROM 
  states 
  INNER JOIN states_meta ON 
    states.metadata_id = states_meta.metadata_id
WHERE 
  states_meta.entity_id = 'sensor.temperature_in' 
  AND last_updated_ts <= strftime('%s', 'now', '-1 day')
ORDER BY 
  last_updated_ts DESC 
LIMIT
  1;

Replace -1 day with the target offset, for example, -1 hour. Use state as column for value.

Keep in mind that, depending on the update frequency of your sensor and other factors, this may not be a 100% accurate reflection of the actual situation you are measuring. Since your database won’t necessarily have a value saved exactly 24 hours ago, use “>=” or “<=” to get one of the closest values.

MariaDB

On MariaDB the following where clause can be used to compare the timestamp:

...
  AND last_updated_ts <= UNIX_TIMESTAMP(NOW() - INTERVAL 1 DAY)
...

Replace - INTERVAL 1 DAY with the target offset, for example, - INTERVAL 1 HOUR.

Database size

Postgres

SELECT pg_database_size('dsmrreader')/1024/1024 as db_size;

Use db_size as column for value. Replace dsmrreader with the correct name of your database.

MariaDB/MySQL

Change table_schema="homeassistant" to the name that you use as the database name, to ensure that your sensor will work properly.

SELECT table_schema "database", Round(Sum(data_length + index_length) / POWER(1024,2), 1) "value" FROM information_schema.tables WHERE table_schema="homeassistant" GROUP BY table_schema;

Use value as column for value.

SQLite

If you are using the recorder integration then you don’t need to specify the location of the database. For all other cases, add sqlite:////path/to/database.db as Database URL.

SELECT ROUND(page_count * page_size / 1024 / 1024, 1) as size FROM pragma_page_count(), pragma_page_size();

Use size as column for value.

MS SQL

Use the same Database URL as for the recorder integration. Change DB_NAME to the name that you use as the database name, to ensure that your sensor will work properly. Be sure username has enough rights to access the sys tables.

Example Database URL: "mssql+pyodbc://username:password@SERVER_IP:1433/DB_NAME?charset=utf8&driver=FreeTDS"

SELECT TOP 1 SUM(m.size) * 8 / 1024 as size FROM sys.master_files m INNER JOIN sys.databases d ON d.database_id=m.database_id WHERE d.name='DB_NAME';

Use size as column for value.