nullSecKeyCompare

The nullSecKeyCompare element is used to define how the Duplicate Detect engine behaves when it compares a non-null secondary key value to fields containing a null value. The nullSecKeyCompare element has an attribute, nullCompareDec, that indicates whether a null value compared with a non-null value is or is not called a potential duplicate. Valid values for nullCompareDec are:
  • N - indicates that a null value compared to a non-null value is called a non-duplicate
  • P - indicates that a null value compared to a non-null value is called a potential duplicate. This value is the default.
The following example shows how to specify an overall default value for nullSecKeyCompare and override that default for specific fields: 
<nullSecKeyCompare nullCompareDec="P">
  <fields>
    <field colName="EPC" nullCompareDec="N"/>
    <field colName="AUX_ONUS" nullCompareDec="N"/>
  </fields>
</nullSecKeyCompare>

Setting the nullCompareDec attribute of the nullSecKeyCompare element specifies a default value for all null to secondary key comparisons. This default value is overridden for individual fields by using the fields element within nullSecKeyCompare. Specify a field element for each field to be overridden.

In the example, the overall null comparison default for the nullSecKeyCompare element is set to P for potential duplicate. The EPC and AUX_ONUS fields are overridden and set to N for non-duplicate.

Note:
  1. In the field element, the value specified for the colName attribute must exactly match the name of the secondary key. If a namespace contains a colName attribute that does not exactly match a column name in the database, the namespace is not loaded and an error is reported.
  2. When the nullSecKeyCompare element is not specified, or it does not have a nullCompareDec attribute, the default is that a null value compared with a non-null value is called a potential duplicate.