User Guide > Designing and Executing Data Profile > Derived Fields
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Derived Fields
Derived fields are not part of the original source data file or table. Instead, they are dynamically generated in memory using specific rules or scripts. These fields are created using function or conversion rules applied to existing fields, allowing you to generate new output fields derived from the original field.
Derived fields can be leveraged for further rule creation (see Add Rules from Derived Fields) or used in calculations within scripts.
By default derived fields are non output fields and are listed under -NonOutputFields- (see Managing Rules from Rules Tab). Non-output-fields are fields that exist in memory, have rules defined on them, but are not written to the target (output). However you can use the Add source/derived fields to output option to write them to target (see Add Source/Derived Fields to Output).
The following are some examples of derived field usage:
Example 1:
If your source data file contains a string field called DateOfBirth and you need it to be a date field for further calculations, you can use the StringToConversion rule to convert it into a date data type derived field. This will generate a derived field called d_DateOfBirth_StringToConversion. You can then create additional rules for the derived field (see Add Rules from Derived Fields) or write it to the target (see Add Source/Derived Fields to Output).
Note:  In the Add Rules dialog, or in the Expression column of the Rules tab > Field/Rule pane, the derived field, is listed below all the source fields.
Example 2:
If your field is a string but should be a numeric field, and you need to test that the field values are not greater than 2000, you can follow these steps:
First, use the StringToConversion rule to convert the string field into a numeric data type derived field. This will generate a derived field called d_FieldName_StringToConversion. This derived field will now be available for further use.
Next, apply the CompareToConstant rule to this derived field. Set the Operator to ">" and specify the Constant value as 2000.
Refer to the following topics for more information:
 
Last modified date: 01/08/2026