New custom component: SQL Sensor

[Robbrad (Rob)]

This could be an unsung hero among sensors!! I have a ton of SQL data that I want to present or alert on

I’m using it to detect if my IoT air quality device hasn’t sent data for a set period of time

I had issues on the install - this fixed it

Error in setting up recorder with MySQL

While this is working a maybe better approach is to just install mysqlclient, a Python 3 compatible mysql-python fork. Because (as I understand) this package uses c-extensions and is thus theoretically faster then the pure python pymsql package. TL:DR: Run in your hass virtual environment: pip install mysqlclient and leave your config at db_url: 'mysql://user:psw@localhost/hass'