The KSQL CLI is a command prompt to interact with KSQL; it is very similar to the one that comes with relational databases such as MariaDB or MySQL. To see all the possible commands, type help and a list with the options will be displayed.
At the moment, we have not informed KSQL of anything. We must declare that something is a table or a stream. We will use the information produced from previous chapters with the producers that write JSON information to the healthchecks topic.
If you remember, the data looks like this:
{"event":"HEALTH_CHECK","factory":"Lake Anyaport","serialNumber":"EW05-HV36","type":"WIND","status":"STARTING","lastStartedAt":"2018-09-17T11:05:26.094+0000","temperature":62.0,"ipAddress":"15.185.195...
