DataTableReader.GetDouble(Int32) Method
Definition
Important
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Gets the value of the column as a double-precision floating point number.
public:
override double GetDouble(int ordinal);public override double GetDouble(int ordinal);override this.GetDouble : int -> doublePublic Overrides Function GetDouble (ordinal As Integer) As Double- ordinal
- Int32
The zero-based ordinal of the column.
The value of the specified column.
The index passed was outside the range of 0 to FieldCount - 1.
An attempt was made to retrieve data from a deleted row.
An attempt was made to read or access a column in a closed DataTableReader.
The specified column does not contain a double-precision floating point number.
The following example displays the contents of the column numbered 2 within the passed-in DataTableReader. If the value the column within a particular row is null, the code displays the text <NULL>. If the data within the column is not of the correct type, the example displays an error message for each row.
private static void PrintColumn(DataTableReader reader)
{
// Loop through all the rows in the DataTableReader
while (reader.Read())
{
if (reader.IsDBNull(2))
{
Console.Write("<NULL>");
}
else
{
try
{
Console.Write(reader.GetBoolean(2));
}
catch (InvalidCastException)
{
Console.Write("Invalid data type.");
}
}
Console.WriteLine();
}
}
Private Sub PrintColumn(ByVal reader As DataTableReader)
' Loop through all the rows in the DataTableReader
While reader.Read()
If reader.IsDBNull(2) Then
Console.Write("<NULL>")
Else
Try
Console.Write(reader.GetBoolean(2))
Catch ex As InvalidCastException
Console.Write("Invalid data type.")
End Try
End If
Console.WriteLine()
End While
End Sub
No conversions are performed; therefore the data retrieved must already be a double-precision floating point number or must be coercible to a double-precision floating point number.
Call IsDBNull to see if there are null values before calling this method.
