Issuing a Command that Returns a String Using the GetChars Method

Use the GetChars method to issue a command that returns a string.

1. Declare and initialize a Connection object.
2. Open the connection.
3. Add a Command object to define and execute a SQL statement:

   For C#:

   AseCommand cmd = new AseCommand( 
      "select au_id, copy from blurbs", conn );

   For Visual Basic .NET:

   Dim cmd As New AseCommand( _
      "select au_id, copy from blurbs", conn)

4. Call the ExecuteReader method to return the DataReader object:

   For C#:

   AseDataReader reader = cmd.ExecuteReader();

   For Visual Basic .NET:

   Dim reader As AseDataReader = cmd.ExecuteReader()

   The following code reads the two columns from the result set. The first column is a varchar, while the second column is Text. GetChars is used to read 100 characters at a time from the Text column:

   For C#:

   int length = 100;
   char[] buf = new char[ length ];
   String au_id;
   long dataIndex = 0;
   long charsRead = 0;
   long blobLength = 0;
   while( reader.Read() )
   {
      au_id = reader.GetString(0);
      do 
      {
         charsRead = reader.GetChars(
            1, dataIndex, buf, 0, length);
         dataIndex += length;
         // do something with the chars read	
         //.... some code
         //
         // reinitialize char array
         buf = new char[ length ];
      } while ( charsRead == length );
      blobLength = dataIndex + charsRead;
   }

   For Visual Basic .NET:

   Dim length As Integer = 100
   Dim buf(length) As Char
   Dim au_id As String
   Dim dataIndex As Long = 0
   Dim charsRead As Long = 0
   Dim blobLength As Long = 0
   While reader.Read()
      au_id = reader.GetString(0)
      Do
         charsRead = reader.GetChars( _
            1, dataIndex, buf, 0, length)
         dataIndex = dataIndex + length
         ' do something with the data read
         ' 
         '  use code
         '
         ' reinitialize the char array
         ReDim buf(length)
      Loop While (charsRead = length)
      blobLength = dataIndex + charsRead
   End While

5. Close the DataReader and Connection objects:

   For C#:

   reader.Close();
   conn.Close();

   For Visual Basic .NET:

   reader.Close()
   conn.Close()