Real Time Information Director User Documentation

RTID Metadata Language
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Mapping
The Mapping enrichment looks up fields in a table that correlates external identifying
information, such as a person’s name, with an internal identifier assigned by the Director.
The enrichment is reversible, in that it performs a lookup in one direction for an inbound
document and in the opposite direction for an outbound document. For example, a
Mapping enrichment is used to obtain the internal ID of a patient from the external ID of
the patient in an update document. In the corresponding query, the same enrichment is
used to obtain the patient’s external ID from the internal ID. The goal is to expose the
external ID to the client application, in both inbound and outbound documents, while
storing the internal ID in the database. The searched table should be keyed or indexed in
both directions, unless it is very small, or unless you take pains to ensure that mapping
occurs in only one direction.
Note: This use of the term “mapping” is unrelated to the task, discussed earlier, of
mapping elements of an IDoc to the database.
The Mapping enrichment is often used in records that reference a table keyed using the
SystemKey enrichment. However there is no requirement for these enrichments to be
used together.
A Mapping enrichment requires you to
1. Construct a Mapper object to describe the table that maps external identifiers to
internal ones. The constructor requires you to specify the name of the mapping
table, the column that contains the internal ID, and the column or columns that
contain the corresponding external identifiers.
2. Construct an actual mapping, within a document definition, by calling the map
method of the Mapper object. When you invoke the map method, you specify the
elements of the inbound or outbound document that contain the external
identifiers, and the column of the corresponding database table where the internal
ID is stored or must be stored.
It is possible to use the same mapping table to store different types of internal and
external IDs. For example, you could use the same table to store IDs for people and
organizations. In this case, each row of the mapping table includes a typecode that places
the external and internal IDs in the appropriate category. The steps for creating what we
call a Qualified Mapping enrichments differ only slightly from the steps for creating a
regular Mapping enrichment:
1. Construct an UnqualifiedMapper object to describe the lookup table. The
parameters are the same as for a regular Mapper, except that you must also
specify the column that contains the typecode.