Exclude certain values from plots

I am using the Discrete panel for my Thermostat and here’s what I have:

operation_str can take the values cool,heat, fan, and idle. I want to exclude idle from the plot, but I am not sure how to go about the same. Here’s my current query:

Is there any way to add NOT IN in the current query that I have SELECT "operation_str" FROM "climate.downstairs" WHERE $timeFilter?

Thanks in advance!