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Loop Paths

An element in a schema is looping if its Max Occurs property is greater than 1. A loop path occurs when you draw a link between a looping element in the source schema and a looping element in the destination schema.

Configuring a Loop Path

BizTalk Mapper automatically handles the looping records when you create a loop path.

You can configure a loop path in a map by linking a field in a looping record in the source schema to a field that is in a looping record in the destination schema. The figure below shows a map that copies only food survey records into a master address list.

Map illustrating the use of a loop path.
Loop Path Map

Multiple Loop Paths

A multiple loop path occurs in a map when you link fields contained by two or more looping records to fields contained in a single looping record. The following figure shows an attempt to combine addresses collected from two different surveys into a single master address list.

Map with multiple loop paths
Map With Multiple Loop Paths (Incorrect)

This map will not produce the expected results. When the Mapper encounters multiple loop paths during compilation, it produces a warning and selects the first loop path by default. In order to combine the two different addresses into a single master address list, use a Looping functoid as shown in the map below.

Map illustrating the use of the looping functoid.
Looping Functoid Map (Correct)

The Looping functoid should be used instead of multiple loop paths in the following scenarios:

  1. When the Mapper does not produce the desired output in a multiple loop paths scenario.

  2. To combine multiple repeating structures in an input instance message into a single repeating structure in the output instance message.

  3. To convert a flat schema to a hierarchical schema by mapping a single record to multiple records. This is a common operation in converting flat schemas to Microsoft Commerce Server catalogs.

See Also

How to Add Looping Functoids to a Map
Looping Functoid