According to: https://github.com/agershun/alasql/wiki/XLSX you can send in the sheetid to read out a different sheet.
I can't however find any way to read out the available sheets.
Does anyone know how this should be done?
Instead of using alasql, first read your workbook yourself using the xlsx plugin
// file is instanceof File object
let workbook = XLSX.read(URL.createObjectURL(file));
console.log(workbook.SheetNames);