Manage Data Fields

Handling Nulls

When you open AutoPrep, it parses the input data and suggests how to handle null values and missing key/value pairs. For example, it suggests Empty string for String fields. If you do not change the null handling from Empty string, at runtime, when a row includes a null, AutoPrep replaces it with an empty string. The Manage null values display lists the suggested null handling to the right of each field as shown below:

Fields where AutoPrep found null values have an informational tooltip:

AutoPrep uses the suggested null handling unless you explicitly change it. Roll your cursor over the value to see the others available for that field. You can choose from the following:

For a Boolean field: False, True, Custom input, or Ignore
For numeric types: Average, Zero, Ignore, or Custom input
For a String or a Date field: Empty string, Ignore, Custom input, or Popular

Custom input enables you to specify a value to use for nulls. If you add a value that is not valid for the field type, the null data will output as NaN. Popular causes AutoPrep to calculate and insert the field’s most frequently-used value.

Modifying Null Handling

Modify null handling as follows:

Select the Handle nulls tab to view the Manage null values table:
To change the rule, hover over the pill and choose from the available options:
Click Update.

Using Data Masking

Data masking provides a way to protect sensitive data. AutoPrep supports the following algorithms to hash values so they are no longer human-readable:

When you mask a field, AutoPrep uses the selected algorithm to transform each value into a masked string. Apply data masking to a field from the Preview data pane:

In the field header, hover over the right side of the column and click the three dots to open the options menu:
Select Mask.
Select the algorithm.

AutoPrep applies the algorithm to the values in the field and if the field was not a string, changes its type to a string.