Zero Values Versus Null Values

Zero and null have different meanings in table auditing. A zero value means that the data stored in the field is '0', whereas a null value means that there is no data in the field at all.

For example, consider the following examples:

Example 1:

Attribute Name	Old Value	New Value
Remaining Duration	5	0

In this example, the data for the Remaining Duration field has changed from 5 to 0, suggesting that the activity was completed, or the remaining duration was changed by a user.

Example 2

Attribute Name	Old Value	New Value
Remaining Duration	5

In this example, the data for the Remaining Duration field has changed from 5 to null, suggesting that the activity has been deleted, so that the row has been removed from the table.