How PeopleImport reads .csv and .xls data?

QUESTION: 
How does PeopleImport read .csv and .xls data?

ANSWER:

• PeopleImport uses the standard Microsoft data components to load data from XLS or CSV.
  • These components work great with Access MDB files or a SQL Server connection as the format of the columns are formally defined. 
  • In an XLS or CSV file (and Excel), the data reader will look at the first few rows of data to determine the field type.
  • It then uses that field type to read the data.
    • In the case of a zip code, if the first 5 records are all 5-digit zip codes it will assume that the entire column is a numeric integer and then trim off the data that is supplied from the database.
      • We do not have control on this as it is done by the Microsoft component. 
    • You can try to force the column to be seen as text and make sure that a 5+4 zip code or Canadian postal code is in the first 5 lines.