Hi Hari,
I don't have experience on XS development, so cannot really tell you the technical reason, if there is any. But just looking at the code, there seems to be some spelling mistake. Not sure if it is also in your code or just typing mistakes here.
name ="Col1" ; sqlType = VARCHAR; nullable = flase -------> Shouldn't this be false ?
There are similar spelling mistakes in other lines too (Col 3 and Col4).
Regards,
Ravi