Datatype conversion is handled differently by the access service for the different transfer types.
After converting the incoming source database datatypes, the source datatypes are converted into the actual datatypes of the target columns. If the source and target columns have incompatible datatypes, the transfer ends with an error.
After converting the incoming source database datatypes, the datatype qualifiers specified are used, with the question marks in the template. When the question marks do not have qualifiers, the access service uses the datatypes of the source to determine the default qualifiers.