SQL query of difficulty?

[vaibhav]

Refer to this:

@vaibhav

The conversion formula is

d = (D - 1)/9

where D is the difficulty from 1 to 10 and d is the difficulty in percent

As for the code, you can refer to the FSRS helper add-on. In general, the add-on code should be the first point of reference when you want to retrieve any FSRS-related info.