Unique values symbology method adds all values even if not present in the data

Description

On the 'Unique values' symbology dialog box, when selecting a field and pressing the 'Add all values' button, and the field has coded domains defined, the method adds all domain codes, even if some codes are not present in the data. This also occurs for subtype fields.

A related problem is that frequencies are not calculated for these types of fields; instead, the Count column on the 'Unique values' symbology dialog box is populated with question marks.

Cause

This problem only occurs with geodatabase data, and only if the value field has coded domains defined or is the subtype field. In this scenario, the unique-values-symbology method does not parse the data to determine all unique values; instead, all the coded domains (or subtypes) are added. Values are added even if there are no features present in the data that fall into a particular coded domain or subtype.

Conversely, if there are features in the data that do not fall into a subtype/coded domain, they will not be added to the renderer.

Finally, because the data are not being parsed upon pressing 'Add all values,' the 'Unique values' dialog box does not display counts by default.

Solution or Workaround

• To remove values from the symbology that are not present in the data:

1. Open the Unique values symbology dialog box: Layer properties > Symbology tab > Categories > Unique values.
2. Pick a Value field.
3. Click the Add all values button.
4. Click the Count column header to get frequencies.
5. Select all values with Count = 0.
6. Click the Remove value(s) button.

• To add values to the symbology that are present in the data, but that do not fall into a coded domain or subtype:

1. Open the Unique values symbology dialog box: Layer properties > Symbology tab > Categories > Unique values.
2. Pick a Value field.
3. Click the Add all values button.
4. Click the Add values button to open the Add values dialog box.
5. Type a value under New value and click the Add to List button. Repeat until finished adding values.
6. Click OK to close the Add values dialog box and add the new values to the symbology.