@zloi_templar
I don't understand:

Why are you "saving" (whatever you mean by that) a number as a string? You're asking for trouble, save it as a number.

Is using toFloat() a good idea? floats have limited precision, at least use toDouble()/doubles?

Even then you will lose accuracy. The only "safe" way to store accurate floating point numbers in a database is via its decimal type support.