I work in QGIS 2.8.3 and import an excel file (xlsx version 2013) containing 5 vectors: string, string, double, int, double. All vectors have a heading. However, QGIS tells me that the last double vector is imported as a QString. I also tried to use rounded values and import them as ints, copy everything as value into a brand new file, but to no avail.
I know that you can force QGIS to import vectors from CSV-files as predefined variable types, but I don't want to use CSV-files, and I particularly want to know why it does import one double as double and another double as QString. Is it a bug? If so, when does it occur?