An opaque data type is an atomic data type that you define to extend the database server. The database server has no information about the opaque data type until you provide routines that describe it.
Extending the database server also frequently requires that you create user-defined routines (UDRs) to support the extensions. A UDR is a routine that you create that can be invoked in an SQL statement, by the database server, or from another UDR. UDRs can be part of opaque types, or they can be separate.
The JDBC 3.0 standard provides the java.sql.SQLInput and java.sql.SQLOutput methods to access opaque types. The definition of these interfaces is extended to fully support Informix fixed binary and variable binary opaque types. This extension includes the following interfaces:
In addition, the following classes simplify creating Java opaque types and UDRs in the database server from a JDBC client application:
The UDTManager and UDRManager classes provide an infrastructure for mapping client-side Java classes as opaque data types and UDRs and storing their instances in the database.
This facility works only in client-side JDBC. For details about the features and limitations of server-side JDBC, see the IBM Informix: J/Foundation Developer's Guide.
For detailed information about opaque types and UDRs, see the following manuals:
You can find the online versions of both these guides at http://www.ibm.com/software/data/informix/pubs/library/.
This chapter includes the following topics:
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