Developing a Data Access Layer for Sybase Using ADO.NET: Essentials - Configuring Sybase for data access using ADO.NET
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To work with a Sybase database using ADO.NET natively, we need to have a Sybase database installed on our computer. If the database exists on another server, then we need to install “Sybase client” (or “pc-client”) which is freely downloadable from Sybase's website.
You need to select a custom installation during the installation of Sybase client. You need to “switch on” all ODBC, OLEDB and ADO.NET components during the custom installation of Sybase client (to activate the full use of ADO.NET). The installation also includes some samples of VB.NET solutions for getting connected with the Sybase database. You can have a trial run using those samples for testing connections, datasets, and so on.
The following are the core DLLs of Sybase that deal with data access using ADO.NET:
Sybase.Data.AseClient.dll
sybdrvado11.dll
sybdrvssl.dll
Of all of the above DLLs, we will work with only the assembly “Sybase.Data.AseClient.dll” (which indeed works with the rest of the DLLs) in ADO.NET. It is always suggested to copy all of the three into the “bin” folder of your ASP.NET application (for instance, if you are developing a web application). You also need to add a reference to “Sybase.Data.AseClient” from the “.NET components” (and not from the “bin” folder) to your application, if it needs any data access to the Sybase database.
Another most important issue is that the files “sybdrvado11.dll” and “sybdrvssl.dll” should also be copied into the folder “C:windowsassemblygacSybase.Data.AseClient
1.1.327.0__26e0f1529304f4a7”. The folder is not directly visible from Windows Explorer. You need work with “Run” or “Command Prompt” to go to that folder and copy the files specified. This is a step that everyone tends to forget.
Once the above is properly configured, your .NET applications can easily interact with the Sybase database. A sample connection string (make it into a single line) to get connected to Sybase would be as follows:
Data Source='172.28.4.175';
Port='5000';UID='sa';PWD='';Database='databasename'
You need to modify the above connection string based on the configurations of the Sybase server. If you are not very familiar with such configurations, you need to consult your Sybase database administrator or system administrator.
It is always suggested that you have your connection string in “Web.Config” (if using web forms) or “app.config” (if using Windows forms). You can encrypt the connection string, if you don’t want it to be simply readable.
The “web.config” file may look something like the following:
<?xml version="1.0" encoding="utf-8"?>
<configuration>
<appSettings>
<add key="ConnectionString" value="Data
Source='dbServernameORipaddress';Port='PortNo';UID='sa';
PWD='';Database='databasename'"/>
</appSettings>
<system.web>
.
.
.
The next section will start with developing the DAL.
Next: The Constructor in the Data Access Layer >>
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