HasRows Property (PgSqlDataReader)

In This Topic

Gets a value indicating whether the PgSqlDataReader 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 PgSqlDataReader 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(PgSqlConnection pgConnection)
{
  PgSqlCommand cmd = new PgSqlCommand("SELECT * FROM Test.Dept");
  cmd.FetchSize = 100;
  cmd.Connection = pgConnection;
  pgConnection.Open();
  try
  {
    PgSqlDataReader 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
  {
    pgConnection.Close();
  }
}

Visual Basic

Public Sub FetchResults(ByVal pgConnection As PgSqlConnection)
  Dim cmd As PgSqlCommand = New PgSqlCommand("SELECT * FROM Test.Dept")
  cmd.FetchSize = 100
  cmd.Connection = pgConnection
  pgConnection.Open()
  Try
    Dim reader As PgSqlDataReader = 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
    pgConnection.Close()
  End Try
End Sub

Reference

PgSqlDataReader Class
PgSqlDataReader Members

Send Feedback