Update data-flow-select.md

Author: kromerm

articles/data-factory/data-flow-select.md

@@ -6,7 +6,7 @@ ms.author: makromer
 ms.service: data-factory
 ms.topic: conceptual
 ms.custom: seo-lt-2019
-ms.date: 02/12/2019
+ms.date: 03/08/2020
 ---
 
 # Mapping data flow select transformation
@@ -51,5 +51,10 @@ When you choose rule-based mapping, you are instructing ADF to evaluate your mat
 
 More details on pattern matching is available at the [Column Pattern documentation](concepts-data-flow-column-pattern.md).
 
+### Use rule-based mapping to parameterize the Select transformation
+You can parameterize field maping in the Select transformation by using rule-based mapping. Use the keyword ```name``` to check the incoming column names against a parameter. For example, if you have a data flow parameter called ```mycolumn``` you can create a single Select transformation rule that always maps whatever column name you set ```mycolumn``` to a field name this way:
+
+```name == $mycolumn```
+
 ## Next steps
 * After using Select to rename, reorder, and alias columns, use the [Sink transformation](data-flow-sink.md) to land your data into a data store.