The Data Callback Classes

SourcePro DB : DB Interface Module User’s Guide : PART IV Using Open SQL : Using the Open SQL Classes : The Data Callback Classes

The Open SQL API includes support for user-defined callback methods that facilitate the handling of character and binary data in pieces. Data callbacks are useful for very large data that may not fit in memory for a single database call. They allow data from any source to be sent to the database or to be read from the database and written to any sink. Supported types include the large object types (LOBs).

The DB Interface module provides a set of base classes that define interfaces for specifying data callback methods:

RWDBCharCallback for standard character data

RWDBUChar16Callback for UTF-16 data

RWDBBinaryCallback for binary data

NOTE: 	The data callback mechanism for large data is supported for the Oracle OCI, DB2 CLI, Microsoft SQL Server, ODBC, and Sybase access modules, but not for MySQL or PostgreSQL.