' Nullify Class
' http://www.thoughtproject.com/Snippets/Nullify/

Option Explicit On
Option Strict On

''' <summary>
'''     Converts values to DBNull.Value when null or equal to a value treated as null.
''' </summary>
''' <remarks>
'''     <para>
'''         Each static method examines a value and either returns DBNull.Value or
'''         the value itself.  Most methods have overloads for value types and
'''         nullable types; parameter ordering and naming conventions are as
'''         consistent as possible.  For example, each method is named after the
'''         data type as it appears in the System namespace.
'''     </para>
'''     <para>
'''         Originally from http://www.thoughtproject.com/Snippets/Nullify and
'''         placed into the public domain by the author.  Check the above site
'''         for new versions.
'''     </para>
''' </remarks>
Public NotInheritable Class Nullify

    Private Sub New()
    End Sub

    ''' <summary>
    '''     Returns DBNull.Value if a nullable Boolean is null.
    ''' </summary>
    Public Shared Function [Boolean](ByVal value As Nullable(Of Boolean)) As Object

        If value.HasValue Then
            Return value.Value
        Else
            Return DBNull.Value
        End If

    End Function


    ''' <summary>
    '''     Returns DBNull.Value if a nullable Boolean is null or matches a specified value.
    ''' </summary>
    Public Shared Function [Boolean]( _
          ByVal value As Nullable(Of Boolean), _
          ByVal treatedAsNull As Boolean) As Object

        If Not value.HasValue OrElse value.Value = treatedAsNull Then
            Return DBNull.Value
        Else
            Return value.Value
        End If

    End Function


    ''' <summary>
    '''     Returns DBNull.Value if a byte array is null.
    ''' </summary>
    Public Shared Function ByteArray(ByVal value As Byte()) As Object

        If value Is Nothing Then
            Return DBNull.Value
        Else
            Return value
        End If

    End Function


    ''' <summary>
    '''     Returns DBNull.Value if a DateTime is the minimum possible date.
    ''' </summary>
    Public Shared Function DateTime(ByVal value As DateTime) As Object

        If value = System.DateTime.MinValue Then
            Return DBNull.Value
        Else
            Return value
        End If

    End Function


    ''' <summary>
    '''     Returns DBNull.Value if a DateTime matches a reserved value.
    ''' </summary>
    Public Shared Function DateTime( _
          ByVal value As DateTime, _
          ByVal treatedAsNull As DateTime) As Object

        If value = treatedAsNull Then
            Return DBNull.Value
        Else
            Return value
        End If

    End Function


    ''' <summary>
    '''     Returns DBNull.Value if a DateTime is null.
    ''' </summary>
    Public Shared Function DateTime(ByVal value As Nullable(Of DateTime)) As Object

        If value.HasValue Then
            Return value.Value
        Else
            Return DBNull.Value
        End If

    End Function


    ''' <summary>
    '''     Returns DBNull.Value if a DateTime is null or matches a reserved value.
    ''' </summary>
    Public Shared Function DateTime( _
          ByVal value As Nullable(Of DateTime), _
          ByVal treatedAsNull As DateTime) As Object

        If Not value.HasValue OrElse value.Value = treatedAsNull Then
            Return DBNull.Value
        Else
            Return value.Value
        End If

    End Function


    ''' <summary>
    '''     Returns DBNull.Value if a decimal is zero.
    ''' </summary>
    Public Shared Function [Decimal](ByVal value As Decimal) As Object

        If value = 0 Then
            Return DBNull.Value
        Else
            Return value
        End If

    End Function


    ''' <summary>
    '''     Returns DBNull.Value if a decimal matches a reserved value.
    ''' </summary>
    Public Shared Function [Decimal]( _
          ByVal value As Decimal, _
          ByVal treatedAsNull As Decimal) As Object

        If value = treatedAsNull Then
            Return DBNull.Value
        Else
            Return value
        End If

    End Function


    ''' <summary>
    '''     Returns DBNull.Value if a nullable Decimal is null.
    ''' </summary>
    ''' <param name="value"></param>
    ''' <returns></returns>
    ''' <remarks></remarks>
    Public Shared Function [Decimal](ByVal value As Nullable(Of Decimal)) As Object

        If value.HasValue Then
            Return value.Value
        Else
            Return DBNull.Value
        End If

    End Function


    ''' <summary>
    '''     Returns DBNull.Value if a Decimal is null or matches a reserved value.
    ''' </summary>
    ''' <param name="value"></param>
    ''' <param name="treatedAsNull"></param>
    ''' <returns></returns>
    ''' <remarks></remarks>
    Public Shared Function [Decimal]( _
          ByVal value As Nullable(Of Decimal), _
          ByVal treatedAsNull As Decimal) As Object

        If Not value.HasValue OrElse value.Value = treatedAsNull Then
            Return DBNull.Value
        Else
            Return value.Value
        End If

    End Function


    ''' <summary>
    '''     Returns DBNull.Value if a Double is 0.0.
    ''' </summary>
    Public Shared Function [Double](ByVal value As Double) As Object
        If value = 0.0 Then
            Return DBNull.Value
        Else
            Return value
        End If

    End Function


    ''' <summary>
    '''     Returns DBNull.Value if a Double matches a reserved value.
    ''' </summary>
    Public Shared Function [Double]( _
          ByVal value As Double, _
          ByVal treatedAsNull As Double) As Object

        If value = treatedAsNull Then
            Return DBNull.Value
        Else
            Return value
        End If
    End Function


    ''' <summary>
    '''     Returns DBNull.Value if a nullable Double is null.
    ''' </summary>
    ''' <param name="value"></param>
    ''' <returns></returns>
    ''' <remarks></remarks>
    Public Shared Function [Double](ByVal value As Nullable(Of Double)) As Object

        If value.HasValue Then
            Return value.Value
        Else
            Return DBNull.Value
        End If

    End Function



    ''' <summary>
    '''     Returns DBNull.Value if a Double is null or matches a reserved value.
    ''' </summary>
    Public Shared Function [Double]( _
          ByVal value As Nullable(Of Double), _
          ByVal treatedAsNull As Double) As Object

        If Not value.HasValue OrElse value.Value = treatedAsNull Then
            Return DBNull.Value
        Else
            Return value.Value
        End If

    End Function


    ''' <summary>
    '''     Returns DBNull.Value if a Guid is empty.
    ''' </summary>
    Public Shared Function Guid(ByVal value As Guid) As Object

        If value = System.Guid.Empty Then
            Return DBNull.Value
        Else
            Return value
        End If

    End Function


    ''' <summary>
    '''     Returns DBNull.Value if a Guid matches a reserved value.
    ''' </summary>
    Public Shared Function Guid( _
          ByVal value As Guid, _
          ByVal treatedAsNull As Guid) As Object

        If value = treatedAsNull Then
            Return DBNull.Value
        Else
            Return value
        End If

    End Function


    ''' <summary>
    '''     Returns DBNull.Value if a Guid is null.
    ''' </summary>
    Public Shared Function Guid(ByVal value As Nullable(Of Guid)) As Object

        If value.HasValue Then
            Return value.Value
        Else
            Return DBNull.Value
        End If

    End Function


    ''' <summary>
    '''     Returns DBNull.Value if a nullable Guid is null or matches a reserved value.
    ''' </summary>
    Public Shared Function Guid( _
          ByVal value As Nullable(Of Guid), _
          ByVal treatedAsNull As Guid) As Object

        If Not value.HasValue OrElse value.Value = treatedAsNull Then
            Return DBNull.Value
        Else
            Return value.Value
        End If

    End Function


    ''' <summary>
    '''     Returns DBNull.Value if an Int16 is zero.
    ''' </summary>
    Public Shared Function Int16(ByVal value As Int16) As Object

        If value = 0 Then
            Return DBNull.Value
        Else
            Return value
        End If

    End Function


    ''' <summary>
    '''     Returns DBNull.Value if an Int16 matches a reserved value.
    ''' </summary>
    Public Shared Function Int16( _
          ByVal value As Int16, _
          ByVal treatedAsNull As Int16) As Object

        If value = treatedAsNull Then
            Return DBNull.Value
        Else
            Return value
        End If
    End Function


    ''' <summary>
    '''     Returns DBNull.Value if an Int16 is null.
    ''' </summary>
    Public Shared Function Int16(ByVal value As Nullable(Of Int16)) As Object

        If value.HasValue Then
            Return value.Value
        Else
            Return DBNull.Value
        End If

    End Function


    ''' <summary>
    '''     Returns DBNull.Value if an Int16 is null or matches a reserved value.
    ''' </summary>
    Public Shared Function Int16( _
          ByVal value As Nullable(Of Int16), _
          ByVal treatedAsNull As Int16) As Object

        If Not value.HasValue OrElse value.Value = treatedAsNull Then
            Return DBNull.Value
        Else
            Return value.Value
        End If

    End Function



    ''' <summary>
    '''     Returns DBNull.Value if an Int32 is zero.
    ''' </summary>
    Public Shared Function Int32(ByVal value As Int32) As Object

        If value = 0 Then
            Return DBNull.Value
        Else
            Return value
        End If

    End Function


    ''' <summary>
    '''     Returns DBNull.Value if an Int32 matches a reserved value.
    ''' </summary>
    Public Shared Function Int32( _
          ByVal value As Int32, _
          ByVal treatedAsNull As Int32) As Object

        If value = treatedAsNull Then
            Return DBNull.Value
        Else
            Return value
        End If

    End Function


    ''' <summary>
    '''     Returns DBNull.Value if an Int32 is null.
    ''' </summary>
    Public Shared Function Int32(ByVal value As Nullable(Of Int32)) As Object

        If value.HasValue Then
            Return value.Value
        Else
            Return DBNull.Value
        End If

    End Function


    ''' <summary>
    '''     Returns DBNull.Value if an Int32 is null or matches a reserved value.
    ''' </summary>
    Public Shared Function Int32( _
          ByVal value As Nullable(Of Int32), _
          ByVal treatedAsNull As Int32) As Object

        If Not value.HasValue OrElse value.Value = treatedAsNull Then
            Return DBNull.Value
        Else
            Return value.Value
        End If

    End Function



    ''' <summary>
    '''     Returns DBNull.Value if an Int64 is zero.
    ''' </summary>
    Public Shared Function Int64(ByVal value As Int64) As Object

        If value = 0 Then
            Return DBNull.Value
        Else
            Return value
        End If

    End Function


    ''' <summary>
    '''     Returns DBNull.Value if an Int64 matches a reserved value.
    ''' </summary>
    Public Shared Function Int64( _
          ByVal value As Int64, _
          ByVal treatedAsNull As Int64) As Object

        If value = treatedAsNull Then
            Return DBNull.Value
        Else
            Return value
        End If

    End Function


    ''' <summary>
    '''     Returns DBNull.Value if an Int64 is null.
    ''' </summary>
    Public Shared Function Int64(ByVal value As Nullable(Of Int64)) As Object

        If value.HasValue Then
            Return value.Value
        Else
            Return DBNull.Value
        End If

    End Function


    ''' <summary>
    '''     Returns DBNull.Value if an Int64 is null or matches a reserved value.
    ''' </summary>
    Public Shared Function Int64( _
          ByVal value As Nullable(Of Int64), _
          ByVal treatedAsNull As Int64) As Object

        If Not value.HasValue OrElse value.Value = treatedAsNull Then
            Return DBNull.Value
        Else
            Return value.Value
        End If

    End Function


    ''' <summary>
    '''     Returns DBNull.Value if a Single is zero.
    ''' </summary>
    Public Shared Function [Single](ByVal value As Single) As Object

        If value = 0.0 Then
            Return DBNull.Value
        Else
            Return value
        End If

    End Function


    ''' <summary>
    '''     Returns DBNull.Value if a Single matches a reserved value.
    ''' </summary>
    Public Shared Function [Single]( _
          ByVal value As Single, _
          ByVal treatedAsNull As Single) As Object

        If value = treatedAsNull Then
            Return DBNull.Value
        Else
            Return value
        End If

    End Function


    ''' <summary>
    '''     Returns DBNull.Value if a Single is null.
    ''' </summary>
    Public Shared Function [Single](ByVal value As Nullable(Of Single)) As Object

        If value.HasValue Then
            Return value.Value
        Else
            Return DBNull.Value
        End If

    End Function


    ''' <summary>
    '''     Returns DBNull.Value if a Single is null or matches a reserved value.
    ''' </summary>
    Public Shared Function [Single]( _
          ByVal value As Nullable(Of Single), _
          ByVal treatedAsNull As Single) As Object

        If Not value.HasValue OrElse value.Value = treatedAsNull Then
            Return DBNull.Value
        Else
            Return value.Value
        End If

    End Function


    ''' <summary>
    '''     Returns DBNull.Value if a String is null or empty.
    ''' </summary>
    Public Shared Function [String](ByVal value As String) As Object

        If String.IsNullOrEmpty(value) Then
            Return DBNull.Value
        Else
            Return value
        End If

    End Function

End Class