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