> What are the function present in mysql++ for
> dump the database into microsoft XL file.
There are no large-scale data format conversion functions of any sort in
MySQL++. That is not its purpose.
You could use MySQL++ to write such a thing, with MySQL++ handling the
"read from MySQL" part, but it would be up to you to figure out how to
write the data you retrieve out in Excel format.
If you just need a simple one-time data conversion (i.e. not something
ongoing or needing automation) I recommend MySQL's Query Browser tool: