Data Importer does not populate a Contact's last name of Null (example- Sharon Null)
a: Administration tab\System Configuration\Data Importer Engine\*String represesnting No Data or Null Value in Import Data File (case insensitive)
a. Existing datafiles contain 'NULL'/(blank) values which are intended to insert DBNull.
b. Now user would like to insert NULLString into (say) 'Middle Name'.
c. User changes value in the new field introduced in SystemConfig-DataImporter to (example) 'dummy' (can be any value though).
d. User will need to replace all the existing 'NULL' occurrences in data file and with 'dummy' string.
e. And enter ‘NULL’ (case insensitive) in the DataFile wherever Middle Name needs to have NULLString. (example ‘Jane Null’).
And replace all ‘NULL’ occurrences in their data file with the value mentioned in the New Field in Systemconfiguration.
And use ‘NULL’ in wherever use need to insert NULLString.
NOTE:
If there is NO value in the Data File for the particular field, it is considered DBNull while writing to DB regardless of string configured in System Configuration page.