Add back yaml support (#24293)

Co-authored-by: Franck Nijhof <frenck@frenck.nl>
Co-authored-by: J. Nick Koston <nick@koston.org>

source/_integrations/sql.markdown

@@ -19,8 +19,68 @@ ha_integration_type: integration
 The `sql` sensor platform enables you to use values from an [SQL](https://en.wikipedia.org/wiki/SQL) database supported by the [sqlalchemy](https://www.sqlalchemy.org) 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.**
+
 {% include integrations/config_flow.md %}
 
+## 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):
+
+{% raw %}
+```yaml
+# Example configuration.yaml
+sql:
+  - name: Sun state
+    query: >
+      SELECT *
+      FROM states
+      WHERE entity_id = 'sun.sun'
+      ORDER BY state_id
+      DESC LIMIT 1;
+    column: "state"
+```
+{% endraw %}
+
+{% configuration %}
+sql:
+  description: Integration.
+  required: true
+  type: map
+  keys:
+    db_url:
+      description: The URL which points to your database. See [supported engines](/integrations/recorder/#custom-database-engines).
+      required: false
+      default: "Defaults to the default recorder `db_url` (not the current `db_url` of recorder)."
+      type: string
+    name:
+      description: The name of the sensor.
+      required: true
+      type: string
+    query:
+      description: An SQL QUERY string, should return 1 result at most.
+      required: true
+      type: string
+    column:
+      description: The field name to select.
+      required: true
+      type: string
+    unit_of_measurement:
+      description: Defines the units of measurement of the sensor, if any.
+      required: false
+      type: string
+    value_template:
+      description: Defines a template to extract a value from the payload.
+      required: false
+      type: template
+    unique_id:
+      description: Provide a unique id for this sensor.
+      required: false
+      type: string
+{% endconfiguration %}
+
 ## Information
 
 See [supported engines](/integrations/recorder/#custom-database-engines) for which you can connect with this integration.