You can run this query from VB.net using DATAReader and Data connection object
select data_type
from information_schema.columns
where table_schema = 'myschema'
and table_name = 'mytable'
and column_name = 'mycol'
Replace your database , table , field names
You can run query for alteration of field to change type , size in my sql
read below mysql blog to know more about ALTER query
ALTER TABLE Syntax[
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