HasRows Property (PgSqlDataReader)
Gets a value indicating whether the
PgSqlDataReader contains one or more rows.
public override bool HasRows {get;}
'Declaration
Public Overrides ReadOnly Property HasRows As Boolean
Property Value
true if the
PgSqlDataReader contains one or more rows; otherwise,
false.
This sample shows how to optimize reading from a data source using
HasRows property.
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();
}
}
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
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