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Overview of Oracle Objects for OLE (OO4O)

OraAQMsg

The OraAQMsg object encapsulates the message to be enqueued or dequeued. The message can be of any user-defined or raw type.

For a detailed description of Oracle Advanced Queuing, refer to Oracle Streams Advanced Queuing User's Guide and Reference.

OraAQAgent

The OraAQAgent object represents a message recipient and is only valid for queues that allow multiple consumers. It is a child of OraAQMsg.

An OraAQAgent object can be instantiated by invoking the AQAgent method. For example:

Set agent = qMsg.AQAgent(name)

An OraAQAgent object can also be instantiated by invoking the AddRecipient method. For example:

Set agent = qMsg.AddRecipient(name, address, protocol).

Support for Oracle LOB and Object Datatypes

Oracle Objects for OLE provides full support for accessing and manipulating instances of object datatypes and LOBs in Oracle Database. Figure 1–4, "Supported Oracle Datatypes" illustrates the datatypes supported by OO4O.

Instances of these types can be fetched from the database or passed as input or output variables to SQL statements and PL/SQL blocks, including stored procedures and functions. All instances are mapped to COM Automation Interfaces that provide methods for dynamic attribute access and manipulation.

Programmatic Environments 1-37

Overview of Oracle Objects for OLE (OO4O)

Figure 1–4 Supported Oracle Datatypes

OraObject

OraAttribute

OraField

 

OraRef

OraAttribute

OraParameter

 

OraCollection

Element Values

OraParamArray

 

OraBLOB

 

OraCLOB

OraBFILE

Value of all other scalar types

OraBLOB and OraCLOB

The OraBlob and OraClob interfaces in Oracle Objects for OLE provide methods for performing operations on large database objects of datatype BLOB, CLOB, and NCLOB. BLOB, CLOB, and NCLOB datatypes are also referred to here as LOB datatypes.

LOB data is accessed using Read and the CopyToFile methods.

LOB data is modified using Write, Append, Erase, Trim, Copy, CopyFromFile, and CopyFromBFile methods. Before modifying the content of a LOB column in a row, a row lock must be obtained. If the LOB column is a field of an OraDynaset, object, then the lock is obtained by invoking the Edit method.

OraBFILE

The OraBFile interface in Oracle Objects for OLE provides methods for performing operations on large database objects of datatype BFILE.

BFILE objects are large binary data objects stored in operating system files outside of the database tablespaces.

1-38 Oracle Database Application Developer's Guide - Fundamentals

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