Why value revert to zero when job aborted with system error?

I have a codeunit that is use to import some files for updating the pricing on items. One of the pricing becomes zero when the import terminated. The termination was be due to a 'mis-match condition' which hits a system date error. The pricing for those items that were in eg. 1st to 4th files becomes zero even though the import are successful for these earlier
files.

For example: File 1, file 2, file 3 and file 4. File 1 to 3 have been imported successfully whilest there is a system error during the import of file 4 and the job got aborted.

Why is it so that the pricing for the items in File 1 to 3 becomes zeros instead of rolling back to a previous values or not writting to the database at all?

:roll: