Mastering Crystal Reports 9 [Electronic resources] نسخه متنی

Native Connections

A native connection is one made from Crystal to a data source using a DLL that is specific to the database itself and that is sometimes provided directly by the database manufacturer. Native drivers are used for these connections and are the preferred way to access a database using Crystal, if one is available, because they have been optimized for fast, efficient direct access to data for that type of database. Figure 10.17 depicts the close relationship between the native driver and the database itself.

Figure 10.17. Native drivers

Crystal ships with a long list of native driver DLL files. The following table shows a partial list of native drivers that are placed on a computer during the installation of Crystal Reports. The driver itself, however, is not actually installed until you connect to it for the first time in Crystal Reports.

When you read the filenames, the characters to the left of the period give you a hint as to what type of data the driver retrieves. For instance, the p2bact3.dll retrieves data from Act! 3.0 databases, and p2soutlk.dll retrieves data from Outlook databases.

In the Crystal Reports interface, you select the native drivers through the Create New Connection folder and its More Data Sources option in the Database Expert, as shown in Figure 10.18.

Figure 10.18. Native drivers in Database Expert

When you expand the Create New Connection folder in the Database Expert, a list of friendly names describing the DLLs that were found on the computer is shown. The friendly version of the name tells you what database it is rather than showing the actual DLL filename. On the initial install of Crystal Reports, the following databases can be accessed with native drivers stored on your computer:

ACT! 3.0

ADO.NET

Borland Database Engine

Btrieve

CDO

COM Data

Dataset Consumer

Exchange Folders/Address Book

Field Definitions

File System Data

IBM DB2

Informix

Java Data

Lotus Domino

Mailbox Admin

Message Tracking Loc

Miracle Systems IIS/Proxy Log Files

NT Archived Event Log

NT Current Event Log

Oracle

Outlook

Public Folder ACL

Public Folder Admin

Public Folder Replica

Sybase

Web/IIS Log Files

xBase

To install the driver for any of the additional data sources, you double-click it and Crystal Reports installs the driver. Once the driver is installed, that type of data source is moved out of the list of More Data Sources and added to the list of data sources directly under the Create New Connection folder.

A connection to an Oracle server, for instance, would use a native connection making use of software provided by Oracle. If an Oracle client exists on a computer, the Net8 Easy Config utility would configure the client for communication with an Oracle server. The process of using the configuration utility installs the necessary native drivers to the computer, therefore making them available to Crystal Reports.