Object-Oriented database design with the DatabaseObjects library

Option Explicit On 

Imports DatabaseObjects
Imports System.Collections


Public Class Territories
    Inherits DatabaseObjects.DatabaseObjectsEnumerable

    Friend Sub New(ByVal objDatabase As Database)

        MyBase.New(objDatabase)

    End Sub

    Public Function Exists(ByVal strDescription As String) As Boolean

        Exists = MyBase.ObjectExists(strDescription)

    End Function

    Public Sub Delete(ByRef objItem As Territory)

        MyBase.ObjectDelete(objItem)

    End Sub

    Protected Overrides Function DistinctFieldAutoIncrements() As Boolean

        Return False

    End Function

    Protected Overrides Function DistinctFieldName() As String

        Return "TerritoryID"

    End Function

    Protected Overrides Function ItemInstance() As IDatabaseObject

        Return New Territory

    End Function

    Protected Overrides Function KeyFieldName() As String

        Return "TerritoryDescription"

    End Function

    Protected Overrides Function OrderBy() As SQL.SQLSelectOrderByFields

        OrderBy = New SQL.SQLSelectOrderByFields
        OrderBy.Add("TerritoryDescription", SQL.OrderBy.Ascending)

    End Function

    Protected Overrides Function Subset() As SQL.SQLConditions

    End Function

    Protected Overrides Function TableJoins(ByVal objPrimaryTable As SQL.SQLSelectTable, ByVal objTables As SQL.SQLSelectTables) As SQL.SQLSelectTableJoins

    End Function

    Protected Overrides Function TableName() As String

        Return "Territories"

    End Function

End Class



Public Class Territory
    Inherits DatabaseObjectUsingAttributes

    Private pintID As Integer
    Private pstrDescription As String
    Private pobjRegion As New DatabaseObjects.ObjectReference

    Public Sub New()

        MyBase.New(NorthwindDB.Territories)

    End Sub

    <DatabaseObjects.FieldMapping("TerritoryID")> _
    Public Property ID() As String
        Get

            Return pintID

        End Get

        Set(ByVal Value As String)

            pintID = Integer.Parse(Value)

        End Set
    End Property

    <DatabaseObjects.FieldMapping("TerritoryDescription")> _
    Public Property Description() As String
        Get

            Return pstrDescription

        End Get

        Set(ByVal Value As String)

            pstrDescription = Value.Trim

        End Set
    End Property

    <DatabaseObjects.FieldMapping("RegionID")> _
    Private Property RegionID() As Integer
        Get

            Return pobjRegion.DistinctValue

        End Get

        Set(ByVal Value As Integer)

            pobjRegion = New DatabaseObjects.ObjectReference(NorthwindDB.Regions, Value)

        End Set
    End Property

    Public Property Region() As Region
        Get

            Return pobjRegion.Object

        End Get

        Set(ByVal Value As Region)

            If Value Is Nothing Then
                Throw New ArgumentNullException
            Else
                pobjRegion.Object = Value
            End If

        End Set
    End Property

    Public Overloads Sub Save()

        If pintID = 0 Then
            Throw New ArgumentException("Territory ID")
        End If

        If pobjRegion.ObjectIsNothing Then
            Throw New NullReferenceException("Region")
        End If

        MyBase.Save()

    End Sub

    'Protected Overrides Sub LoadFields(ByVal objFields As DatabaseObjects.SQL.SQLFieldValues)

    '    pintID = objFields("TerritoryID").Value
    '    Description = objFields("TerritoryDescription").Value
    '    Description = Description.Trim
    '    pobjRegion = NorthwindDB.Regions.LateboundObject(objFields("RegionID").Value)

    'End Sub

    'Protected Overrides Function SaveFields() As DatabaseObjects.SQL.SQLFieldValues

    '    SaveFields = New SQL.SQLFieldValues
    '    SaveFields.Add("TerritoryID", pintID)
    '    SaveFields.Add("TerritoryDescription", Description)
    '    SaveFields.Add("RegionID", pobjRegion.DistinctValue)

    'End Function

End Class