Description
Counts the distinct occurrences of an certain value of an column. This functionality is similar to the SQL distinct() function.
Example
<function class="org.jfree.report.function.CountDistinctFunction" name="Cnt_Dstnct_USA">
<properties>
<property name="field">Country</property>
<property name="group">Product</property>
<property name="value">USA</property>
</properties>
</function>