I have downloaded the Trial version 1.1 of the HXTT Excel driver and when I use
executeUpdate("Alter Table taleName Modify columnName Varchar(10)")
Now HXTT Excel doesn't support alter table.
The Full version of HXTT Excel work whit Alter Table?
It supports only "Alter Table taleName rename TO .." sql now. If you need those above feature, we can support. But because MS Excel can store any value in a cell, that modify data type operation hasn't its meaning in fact.