Release 10.1A: OpenEdge Data Management:
DataServer for ODBC

Programming Considerations

An application developed in the OpenEdge Studio can use the DataServer for ODBC to access data from multiple sources transparently. With the DataServer, your applications can access information in both OpenEdge databases and supported foreign ODBC data sources. This chapter discusses the differences between OpenEdge databases and supported ODBC data sources that you must consider when you plan your applications and design your databases, as well as the DataServer strategies for resolving these differences, which your application might need to accommodate. Specifically, it discusses the following topics:

Database design issues including database objects, naming conventions, limitations, code pages, indexes, views, triggers, and sequences.
Application issues including data types (user defined, arrays, unknown values, zero-length character string), record creation and record locking, transactions, error handling, and cursors.
Progress 4GL issues including the COMPILE statement, field lists, the FIND statements, the ROWID and RECID functions, as well as 4GL statements and functions that the DataServer does not support.
Stored procedures including running native stored procedures from a Progress 4GL procedure, retrieving return codes, setting parameter values, defining buffers and receiving database results, and sending SQL directly to the data source.
Enhancing DataServer performance.

Follow these guidelines carefully when you develop your application to ensure that it can access OpenEdge databases and ODBC data sources transparently.

The material in this chapter is also of interest to users who plan to migrate an OpenEdge database to an ODBC data source. However, such a migration raises additional issues that you must consider when designing your application. For details, see the "Running the Progress-to-ODBC utility" section.