HasRows Property (MySqlDataReader)

In This Topic

Gets a value indicating whether the MySqlDataReader contains one or more rows.

Syntax

Visual Basic
C#

'Declaration
 
Public Overrides ReadOnly Property HasRows As Boolean

public override bool HasRows {get;}

Property Value

true if the MySqlDataReader contains one or more rows; otherwise, false.

Remarks

Note that this property returns true even if all rows were read out.

Example

This sample shows how to optimize reading from a data source using HasRows property.

csharp

public void FetchResults(MySqlConnection myConnection)
{
  MySqlCommand cmd = new MySqlCommand("SELECT * FROM Test.Dept");
  cmd.FetchSize = 100;
  cmd.Connection = myConnection;
  myConnection.Open();
  try
  {
    MySqlDataReader reader = cmd.ExecuteReader();
    if (reader.HasRows)
    {
      while (reader.Read())
      {
        for (int i=0;i<reader.FieldCount;i++)
        {
          Console.Write("\t"+reader[i]);
        }
        Console.WriteLine();
      }
    }
    else
    {
      Console.WriteLine("No rows detected.");
    }
  }
  finally
  {
    myConnection.Close();
  }
}

Visual Basic

Public Sub FetchResults(ByVal myConnection As MySqlConnection)
  Dim cmd As MySqlCommand = New MySqlCommand("SELECT * FROM Test.Dept")
  cmd.FetchSize = 100
  cmd.Connection = myConnection
  myConnection.Open()
  Try
    Dim reader As MySqlDataReader = cmd.ExecuteReader()
    If reader.HasRows Then
      While reader.Read()
        Dim i
        For i = 0 To reader.FieldCount - 1
          Console.Write(String.Concat(" ", reader(i)))
        Next i
        Console.WriteLine()
      End While
    Else
      Console.WriteLine("No rows detected.")
    End If
  Finally
    myConnection.Close()
  End Try
End Sub

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

MySqlDataReader Class
MySqlDataReader Members

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