Raw data import mode allows control over what the content of each node object but requires specially formatted CSV files.
Your CSV file must contain field names in its first row. The following fields are required:
title' the title of the post.
uid' (user ID) or '
name' (user name).
type' the type of the node.
UID or name are ignored if current user does not have administer nodes permission. If the user does have this permission, name is used if available, otherwise UID, otherwise anonymous user is assumed. Your CSV file should use quotes around strings that contain a comma. Parsing is handled by the php fgetcsv function. Field names should match those usually entered into your database.