Connecting to a Database

Connecting to a Database

Once your data provider is installed, you can connect from your application to your database with a connection string. See Table 31 for a list of the connection string options.

NOTE: If your application uses the ADO.NET Entity Framework, you can use the Entity Data Model Wizard to create a new connection or use an existing connection. See Creating a Model for more information.

Example: Using the Provider-Specific Objects

The following example uses the provider-specific objects to connect to a database using the ADO.NET data provider from an application developed in Visual Studio using C#.

1

In the Solution Explorer, right-click References.

2

Click Add Reference; then, select the Pervasive PSQL data provider in the component list. If the data provider is not in the component list, click the Browse tab and navigate to the data provider assembly.

3

Click OK. The Solution Explorer now includes the Pervasive PSQL data provider.

4

Add the data provider’s namespace to the beginning of your application, as shown in the following C# code fragment:

// Access Pervasive PSQL

using System.Data;

using System.Data.Common;

using Pervasive.Data.SqlClient;

5

Add exception handling code and the connection information for your server:

PsqlConnection DBConn = new PsqlConnection("Server DSN=DEMODATA;Host=localhost");

// Open the connection

Console.WriteLine("Connection Successful!")

catch (PsqlException ex)

// Connection failed

writer.WriteLine(ex.Message);

6

Close the connection.

// Close the connection

DBConn.Close();

Example: Using the Common Programming Model

The following example illustrates connecting to a Pervasive PSQL database from an application developed in Visual Studio using C# and the Common Programming Model.

1

Check the beginning of your application. Ensure that the ADO.NET namespaces are present.

// Access Pervasive using factory

using System.Data;

using System.Data.Common;

2

Add the connection information of your server and exception handling code and close the connection.

DbProviderFactory

factory=DbProviderFactories("Pervasive.Data.SqlClient");

DbConnection Conn = factory.createConnection();

Conn.CommandText = "Server DSN=DEMODATA;Host=localhost;";

Console.WriteLine("Connection successful!");

catch (Exception ex)

// Connection failed

Console.WriteLine(ex.Message);

// Close the connection

Example: Using the Pervasive Common Assembly

You can optionally include the Pervasive Common Assembly if you want to use features such as Pervasive Bulk Load in an application that conforms to the Common Programming Model. See Using Pervasive Bulk Load for information about how to use Pervasive Bulk Load with your application.

The following example illustrates how to use the Pervasive Common Assembly in an application developed in Visual Studio using C# and the Common Programming Model.

1

Check the beginning of your application. Ensure the .NET Framework and Pervasive PSQL data provider namespaces are present.

// Access Pervasive PSQL using factory

using System.Data;

using System.Data.Common;

using Pervasive.Data.Common;

2

Add the connection information of your server and exception handling code and close the connection.

// This code does a bulk copy operation from one

// Pervasive PSQL database to another

DbProviderFactory Factory = DbProviderFactories.GetFactory("Pervasive.Data.SqlClient");

DbConnection sourceConnection = Factory.CreateConnection();

sourceConnection.ConnectionString = "Host=localhost;Server DSN=DEMODATA;";

sourceConnection.Open();

DbCommand command = sourceConnection.CreateCommand();

command.CommandText = "SELECT * FROM test";

DbDataReader reader = command.ExecuteReader();

DbConnection destinationConnection = Factory.CreateConnection();

destinationConnection.ConnectionString =
"Host= ntsl2003b;Server DSN=DEMODATA";

destinationConnection.Open();

DbBulkCopy bulkCopy = new DbBulkCopy(destinationConnection);

bulkCopy.DestinationTableName = "test";

bulkCopy.WriteToServer(reader);

catch (DbException ex)

Console.WriteLine( ex.Message );

reader.Close();

MessageBox.Show("done");