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rel hier mapping

Nathan Richardson edited this page Jan 11, 2019 · 3 revisions
Mapping

Icon

metl mapping 48x48 color

Use When

Data needs to be mapped from a relational model to a hierarchical one

Samples

Description

The mapping component allows you to map relational messages to hierarchical messages

Inbound Message Type

Model Based Message

Output Message Type

Model Based Message

Control Message Handling

Input: As entity messages are received this component will process the data. Otherwise, when the input message is not an entity message and the 'Hierarchical Query Method' is 'BY QUERY' and the Unit of Work Boundary is received then the messages will be processed.

Output: A single control message will be forwarded to downstream components once all messages have been processed through this step.

Properties
Name Description

Input Model

Output Model

Error Suspense Step

Whether to forward failed messages and continue processing. This is the name of a linked component to forward the failed messages to.

Enabled

Set Unmapped Attributes To Null

Whether attributes in the output model that don’t have a mapping specified from the input model should be set to null.

Hierarchical Query Method

Determines the method by which hierarchical relationships are formed from the relational data. Either BY_QUERY or BY_JOIN. Defaults to by join. Using the BY_JOIN method, relational data is sent to the relational / hierarchical mapper based on a single joined query from an rdbms reader. When the joined data comes in to the mapper, it completes control/break logic on the data to transform it into the hierarchical model. The control break logic is based on foreign key definitions in the relational model. Using the BY_QUERY method allows one or more queries to be run from one or more rdbms readers for each entity in the hierarchical model.

Log Input

Log Output

Inbound Queue Capacity

Component Editor

Double clicking on the Mapping component in the flow will result in the Mapping editor being displayed as shown below.

hierarchical mapping editor

TODO: Add additional details here…​

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