The Visual Basic Upgrade Companion achieves its high automation ratio and superior code quality by applying advanced transformation rules to adapt the legacy constructions to their respective .NET counterparts.

The .NET platform offers a collection of classes for data access that takes into consideration modern application requirements for distribution, reliability and scalability, plus a provider-independent data access model (System.Data.Common) which enables developers to write ADO.NET code that works against any .NET data provider.

So in terms of the .NET framework, the way to access data has changed: .NET uses XML as its underlying data structure, and even records from databases are represented internally as XML, which is then converted to the data type required by the client application. Data access classes and methods have been re-written by Microsoft, building a new version of ActiveX Data Objects (ADO) called ADO.NET.

This new data access model provides the following advantages:

The Visual Basic Upgrade Companion migrates the legacy data access models (ADO, RDO, DAO, ADOR) to .NET equivalents, employing special transformation rules and helper classes (for some specific source/target combinations).

The Visual Basic Upgrade Companion provides different alternatives to upgrade the data access model to ADO.NET. For example it is possible to upgrade ADO into ADO.NET using the SqlClient libraries. This works perfect when using SQL Server, but if you want your application to connect to any database using a compliant .NET data provider, the tool generates code that uses the classes introduced with version 2.0 of the .NET Framework in the System.Data.Common namespace.

Besides the Data access libraries, the tool is able to upgrade the ADODC and MSRDC data controls.

The possible data source-target combinations are described in this table:

The following example demonstrates a simple usage of ADO for data access with a simple query execution.

Original VB6 source code

Public Sub DataAccessExample()
    Set db = New ADODB.Connection
    Set rs = New ADODB.Recordset
    db.Open "Provider=MSDASQL;DSN=TikkisDb;Password=Password1;"
    rs.Open "SELECT * FROM Table1", db, adOpenKeyset, adLockPessimistic
End Sub 

The Visual Basic Upgrade Companion generated source code employs .NET data access constructions. The user can select from different available techniques to upgrade the data access methodology from the tools Profile Manager screen. Besides the target language, the user can also select the data access library to be employed (SqlClient or System.Data.Common).

VB.NET code generated by the Visual Basic Upgrade Companion using SQLClient libraries

Public Sub DataAccessExample()
    Dim db As New SqlConnection
    Dim rs As New DataSet
      db.ConnectionString = "Provider=MSDASQL;DSN=TikkisDb;Password=Password1;"
    db.Open()
    Dim com As SqlCommand = New SqlCommand()
    com.Connection = db
    com.CommandText = "SELECT * FROM Table1"
	  Dim adap As SqlDataAdapter = New SqlDataAdapter(com.CommandText, com.Connection)
    rs = New DataSet("dsl")
    adap.Fill(rs)
End Sub

C#.NET code generated by the Visual Basic Upgrade Companion using SQLClient libraries

public void  DataAccessExample()
{
    SqlConnection db = new SqlConnection();
    DataSet rs = new DataSet();
    db.ConnectionString = "Provider=MSDASQL;DSN=TikkisDb;Password=Password1;";
    db.Open();
    SqlCommand com = new SqlCommand();
    com.Connection = db;
    com.CommandText = "SELECT * FROM Table1";
    SqlDataAdapter adap = new SqlDataAdapter(com.CommandText, com.Connection);
    rs = new DataSet("dsl");
    adap.Fill(rs);
}

C#.NET code generated by the Visual Basic Upgrade Companion using System.Data.Common namespace

public void  DataAccessExample()
{
	DbConnection db = AdoFactoryManager.GetFactory().CreateConnection();
	RecordSetHelper rs = new RecordSetHelper(AdoFactoryManager.GetFactory());
	db.ConnectionString = "Provider=MSDASQL;DSN=TikkisDb;Password=Password1;";
	db.Open();
	rs.Open("SELECT * FROM Table1", db, LockTypeEnum.adLockPessimistic);
}

Call us today at 1-425-609-8458 or email us at info@mobilize.net