Import Update vs Replace.

[RayYates]

What's the difference?

'Add New and Update Existing Categories'

'Add New and Replace Existing Categories'

If we lookup a record then replace the field data, how is that different than deleting a record and adding it back in?

[RayYates]

Here is why I ask this question. The loop below contains common import options and a description of how I interpret them.

Three problems:
1. It's not clear what Update existing means with respect to fields that are blank in the import file.
2. Replace Existing could mean replace all existing records or it could mean replace record only if it exists.
3. The option that seems to be missing is Replace ALL db_records letting you clear all records before importing.

foreach import_record {
options:

Add New db_record Only // If db_record exists Skip else Add New
Update Existing db_record Only // If db_record exists Update NON BLANK db fields else Skip
Add New and Update Existing db_record // If db_record exists Update NON BLANK db fields else Add New
Replace Existing db_record Only // If db_record exists Update ALL db fields else Skip
Add New and Replace Existing db_record // If db_record exists Delete+Add New else Add New

}

Please clarify.