UniDataReader Class

In This Topic

Allows to read a forward-only stream of rows from a database.

Syntax

Visual Basic
C#

'Declaration
 
Public Class UniDataReader 
   Inherits Devart.Common.DbDataReaderBase
   Implements System.Collections.IEnumerable, System.Data.IDataReader, System.Data.IDataRecord, System.IDisposable

public class UniDataReader : Devart.Common.DbDataReaderBase, System.Collections.IEnumerable, System.Data.IDataReader, System.Data.IDataRecord, System.IDisposable

Remarks

To create a UniDataReader, you must call the ExecuteReader method of the UniCommand object, rather than directly using a constructor.

IsClosed and RecordsAffected are the only properties that you can call after the UniDataReader is closed. In some cases, you must call Close before you can call RecordsAffected.

Example

The following example creates a UniConnection, a UniCommand, and a UniDataReader. The example reads through the data, writing it out to the console. Finally, the example closes the UniDataReader, then the UniConnection.

csharp

public void ReadMyData(string myConnString) 
{
  string mySelectQuery = "SELECT DeptNo, DName FROM Test.Dept";
  UniConnection myConnection = new UniConnection(myConnString);
  UniCommand myCommand = new UniCommand(mySelectQuery,myConnection);
  myConnection.Open();
  try
  {
    UniDataReader myReader = myCommand.ExecuteReader();
    while (myReader.Read()) 
    {
      Console.WriteLine(myReader.GetInt32(0) + ", " + myReader.GetString(myReader.GetOrdinal("DName")));
    }
    myReader.Close();
  }
  finally
  {
    myConnection.Close();
  }
}

Visual Basic

Public Sub ReadMyData(ByVal myConnString As String)
  Dim mySelectQuery As String = "SELECT DeptNo, DName FROM Test.Dept"
  Dim myConnection As New UniConnection(myConnString)
  Dim myCommand As New UniCommand(mySelectQuery, myConnection)
  myConnection.Open()
  Try
    Dim myReader As UniDataReader = myCommand.ExecuteReader()
    ' Always call Read before accessing data.
    While myReader.Read()
      Console.WriteLine(myReader.GetInt32(0).ToString() + ", " _
          + myReader.GetString(myReader.GetOrdinal("DName")))
    End While
    ' always call Close when done reading.
    myReader.Close()
    ' Close the connection when done with it.
  Finally
    myConnection.Close()
  End Try
End Sub

Inheritance Hierarchy

System.Object
   System.MarshalByRefObject
      System.Data.Common.DbDataReader
         Devart.Common.DbDataReaderBase
            Devart.Data.Universal.UniDataReader

Requirements

Target Platforms: Windows 7, Windows Vista SP1 or later, Windows XP SP3, Windows Server 2008 (Server Core not supported), Windows Server 2008 R2 (Server Core supported with SP1 or later), Windows Server 2003 SP2

Reference

UniDataReader Members
Devart.Data.Universal Namespace
UniConnection Class
UniCommand Class

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