Instance Mappings vs Mapping Rules

In the Studio a data mapping essentially consists of a collection of instance mappings. Structurally each instance mapping has a target entity, a single source expression and optionally one or more additional context expressions. The source expression is used to determine which source instances must be mapped to instances of the target entity. Additional context expressions are used to activate an additional source instance, for each source instance, when determining attribute and relation values for each target instance.

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A notable difference between an instance mapping and a mapping rule, other than the specific type, is that a mapping rule may have multiple target entities. For each target entity there also is a separate value mapping and a separate matching strategy.

Rule Type Definitions

The basic mapping scenarios (Direct, Join, Split, Full) are defined by the number of source instances and target instances that are mapped together when executing a mapping rule.

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Examples

The following package contains example projects with data mappings for the Join, Split and Full rule types.

MappingRuleExamples.package.zip

Direct Image Modified

The Direct rule type is most simple rule type. It is used in scenarios where a single instance in the source profile must be mapped to a single instance in the target profile.

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• consists of a single instance mapping
• has no additional contexts defined
• source expression/label is unique across all instance mappings

Join Image Modified

The Join rule type is used in scenarios where data from multiple instances in the source profile must be mapped to a single instance in the target profile.

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• consists of a single instance mapping
• has with additional contexts defined
• source expression/label and list of additional contexts/labels are unique over all instance mappings

Split Image Modified

The Split rule is used when a single source instance must be mapped to multiple target instances.

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• consists of multiple instance mappings
• no additional contexts defined for all instance mappings in the Split mapping rule
• source expression and label is identical for all instance mappings in the Split mapping rule

Full Image Modified

The Full rule is used when multiple source instances must be mapped to multiple target instances.

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• consists of multiple instance mappings
• additional contexts defined for all instance mappings in the Full mapping rule
• source expression/label and list of additional contexts/labels are identical for all instance mappings in the Full mapping rule

Transformation to mapping rules

How the transformation from instance mappings to mapping rules is performed is described in the following steps:

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