Access iSeries services from the middle tier

There are several ways to provide your middle-tier components with access to the iSeries™ server.

Note: Middle-tier components cannot have a user interface; therefore, if iSeries Access prompts for sign-on information, your three-tier applications may appear to hang. To prevent this, developers must use a new system object to specify required connection information (user ID and password) to the iSeries server. The prompt mode value for this object must be prompt never.

iSeries Access for Windows^® .NET Data Provider

The IBM^® DB2^® UDB for iSeries .NET Provider offers the best performance to access the iSeries database for programmers that write applications using Microsoft's .NET Data Access Framework. Throughout this documentation, Managed Provider is used interchangeably with IBM DB2 UDB for iSeries .NET Provider and IBM.Data.DB2.iSeries data provider. Regardless of the name that is referenced, you can take advantage of the full set of .NET data types and SQL functionality to make it easy for applications to work with data stored securely in your iSeries server databases.

See .NET programming for more information.

iSeries Access for Windows OLE DB provider

Most applications and components use the iSeries Access for Windows OLE DB provider through ActiveX Data Objects (ADO). Here are the four primary benefits to implementing this technique:

It allows your developers to make only minor modifications to a single interface and programming technique in order to access iSeries programs, commands, SQL queries, stored procedures, and physical and logical files.
It supports automatic data conversions between iSeries and PC data types.
It allows you to avoid the overhead associated with SQL by providing support for record-level file access.
It is relatively easy to implement and to develop applications. This method is generally the most simple technology for developing three-tier applications.

See OLE DB programming for more information.

iSeries Access for Windows ODBC driver

Additionally, you can access the iSeries Access ODBC driver through either ADO or Remote Data Services (RDS), by using the Microsoft^® OLE DB provider for ODBC (MSDASQL).

For more information about accessing ODBC through ADO, see Choosing an interface to access the ODBC driver.

For other iSeries Access ODBC driver information, see ODBC programming.

Note: The iSeries Access for Windows OLE DB provider, and several functions in the iSeries Access ODBC driver, require MDAC version 2.5 or later.

ActiveX automation objects

The iSeries Access for Windows client provides a library of ActiveX automation objects that your developers can use for middle-tier development. These objects provide access to:

iSeries data queues
Remote commands and distributed program calls
Administration objects
iSeries system objects
Data Transfer access to iSeries database tables

In some cases, ActiveX objects provide greater versatility and functionality than ADO, but require slightly more complex programming.

Note: The iSeries Access for Windows client includes the automation library from the Windows 95/NT client (the XD1 product). These automation objects, including database, do not support use in a three-tier environment.

Express C/C++ APIs