While mssql allows direct insert/update of TEXT fields, it seems that binaries aren't allowed.
So it needs the same type of trick than the used for Oracle (initial insertion to null) and update of image fields later via UpdateBlob().
So, I'll modify these current methods:
allowing them to work, potentially with any DB. Then, conditions in:
insert_record(), update_record() and set_field() will be changed to call them under mssql too.