Connection String is a normal String representation which contains Database connection information to establish the connection between Datbase and the Application. The Connection String includes parameters such as the name of the driver, Server name and Database name , as well as security information such as user name and password. Data providers use a connection string containing a collection of parameters to establish the connection with the database.

The .NET Framework provides mainly three data providers: Microsoft SQL Server, OLEDB and ODBC. Here you can see how to make connection string to these ADO.NET Data Providers.

Microsoft SQL Server Connection String

connetionString ="Data Source = ServerName; Initial Catalog = Databasename; User ID = UserName; Password=Password"

OLEDB Data Provider Connection String

connetionString = "Provider = Microsoft.Jet.OLEDB.4.0; Data Source = yourdatabasename.mdb;"

ODBC Connection String

connetionString = "Driver = {Microsoft Access Driver (*.mdb)}; DBQ = yourdatabasename.mdb;"

Note : You have to provide the necessary informations to the Connection String attributes.

In the following section you can see how to these ADO.NET Data Providers establish connection to the Databse in detail.

SQL Server Connection

OLEDB Connection

ODBC Connection