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Object-Oriented database design with the DatabaseObjects library

, 31 Jan 2007
Demonstrates creating object-oriented database systems with the DatabaseObjects library.
databaseobjects_demo_net.zip
VB.NET
demo
source
Northwind
NorthwindDB
bin
Northwind.vbproj.user
AxInterop.SHDocVw.dll
DatabaseObjects.dll
Interop.SHDocVw.dll
Northwind.exe
NorthwindDatabase.dll
NorthwindDatabase.vbproj.user
Attributes
bin
Database
DatabaseObjects.vbproj.user
Misc
SQL
DatabaseObjects.dll
Data
mysql_northwind.zip
Documentation
DatabaseObjects.chm
databaseobjects_demo_vb6.zip
VB6
demo
regsvr32.exe
source
Northwind
Northwind.vbg
NorthwindDB
ControlAnchor.cls
frmMain.frm
frmMain.frx
frmOrder.frm
frmOrder.frx
frmProducts.frm
frmProducts.frx
frmProductSearch.frm
frmProductSearch.frx
frmProductSearchExtended.frm
frmProductSearchExtended.frx
frmSuppliers.frm
frmSuppliers.frx
Northwind.exe
northwind.RES
Northwind.vbp
Categories.cls
Category.cls
Data.bas
LateBoundObject.cls
NorthwindDatabase.cls
NorthwindDatabase.OBJ
NorthwindDB.dll
NorthwindDB.vbp
Order.cls
OrderDetail.cls
OrderDetails.cls
Orders.cls
Product.cls
Products.cls
ProductSearch.cls
Supplier.cls
Suppliers.cls
bin
Database.cls
DBO.vbp
GlobalDatabase.cls
GlobalDatabaseObjects.cls
IDatabaseObject.cls
IDatabaseObjects.cls
IGlobalDatabaseObjects.cls
ISQLStatement.cls
modMisc.bas
SQLAlterTable.cls
SQLAutoIncrementValue.cls
SQLCondition.cls
SQLConditionFieldCompare.cls
SQLConditionInSelect.cls
SQLConditions.cls
SQLConditionSelect.cls
SQLCreateIndex.cls
SQLCreateTable.cls
SQLDelete.cls
SQLDropIndex.cls
SQLDropTable.cls
SQLFieldValue.cls
SQLFieldValues.cls
SQLIndexExists.cls
SQLIndexField.cls
SQLIndexFields.cls
SQLInsert.cls
SQLSelect.cls
SQLSelectField.cls
SQLSelectFields.cls
SQLSelectGroupByField.cls
SQLSelectGroupByFields.cls
SQLSelectOrderByField.cls
SQLSelectOrderByFields.cls
SQLSelectTable.cls
SQLSelectTableJoin.cls
SQLSelectTableJoinCondition.cls
SQLSelectTableJoinConditions.cls
SQLSelectTableJoins.cls
SQLSelectTables.cls
SQLTableExists.cls
SQLTableField.cls
SQLTableFields.cls
SQLUpdate.cls
SQLUpdateCopyField.cls
SQLUpdateCopyFields.cls
DatabaseObjects_vb6.dll
mysql_northwind.zip
images
templates
databaseobjects_classdiagram.jpg
logo.jpg
databaseobjects_src_net.zip
DatabaseObjects.vbproj.user
DatabaseObjects.dll
databaseobjects_src_vb6.zip
Database.cls
DBO.vbp
GlobalDatabase.cls
GlobalDatabaseObjects.cls
IDatabaseObject.cls
IDatabaseObjects.cls
IGlobalDatabaseObjects.cls
ISQLStatement.cls
modMisc.bas
SQLAlterTable.cls
SQLAutoIncrementValue.cls
SQLCondition.cls
SQLConditionFieldCompare.cls
SQLConditionInSelect.cls
SQLConditions.cls
SQLConditionSelect.cls
SQLCreateIndex.cls
SQLCreateTable.cls
SQLDelete.cls
SQLDropIndex.cls
SQLDropTable.cls
SQLFieldValue.cls
SQLFieldValues.cls
SQLIndexExists.cls
SQLIndexField.cls
SQLIndexFields.cls
SQLInsert.cls
SQLSelect.cls
SQLSelectField.cls
SQLSelectFields.cls
SQLSelectGroupByField.cls
SQLSelectGroupByFields.cls
SQLSelectOrderByField.cls
SQLSelectOrderByFields.cls
SQLSelectTable.cls
SQLSelectTableJoin.cls
SQLSelectTableJoinCondition.cls
SQLSelectTableJoinConditions.cls
SQLSelectTableJoins.cls
SQLSelectTables.cls
SQLTableExists.cls
SQLTableField.cls
SQLTableFields.cls
SQLUpdate.cls
SQLUpdateCopyField.cls
SQLUpdateCopyFields.cls
DatabaseObjects_vb6.dll
Option Strict Off
Option Explicit On

Imports DatabaseObjects
Imports System.Collections

Public Class Categories
    Implements IDatabaseObjects
    Implements IEnumerable

    Default Public ReadOnly Property Item(ByVal intIndex As Integer) As Category
        Get

            Return NorthwindDB.Database.ObjectByOrdinal(Me, intIndex)

        End Get
    End Property

    Default Public ReadOnly Property Item(ByVal strCategoryName As String) As Category
        Get

            Return NorthwindDB.Database.ObjectByKey(Me, strCategoryName)

        End Get
    End Property

    Public ReadOnly Property Count() As Integer
        Get

            Return NorthwindDB.Database.ObjectsCount(Me)

        End Get
    End Property

    Private Function DistinctFieldAutoIncrements() As Boolean Implements IDatabaseObjects.DistinctFieldAutoIncrements

        Return True

    End Function

    Private Function DistinctFieldName() As String Implements IDatabaseObjects.DistinctFieldName

        Return "CategoryID"

    End Function

    Private Function ItemInstance() As IDatabaseObject Implements IDatabaseObjects.ItemInstance

        Return New Category(Me)

    End Function

    Private Function KeyFieldName() As String Implements IDatabaseObjects.KeyFieldName

        Return "CategoryName"

    End Function

    Private Function OrderBy() As SQL.SQLSelectOrderByFields Implements IDatabaseObjects.OrderBy

        Dim objOrderByFields As SQL.SQLSelectOrderByFields = New SQL.SQLSelectOrderByFields

        objOrderByFields.Add("CategoryName", SQL.OrderBy.Ascending)

        Return objOrderByFields

    End Function

    Private Function Subset() As SQL.SQLConditions Implements IDatabaseObjects.Subset

    End Function

    Private Function TableName() As String Implements IDatabaseObjects.TableName

        Return "Categories"

    End Function

    Private Function GetEnumerator() As System.Collections.IEnumerator Implements System.Collections.IEnumerable.GetEnumerator

        Return NorthwindDB.Database.ObjectsList(Me).GetEnumerator

    End Function

    Private Function TableJoins(ByVal objPrimaryTable As DatabaseObjects.SQL.SQLSelectTable, ByVal objTables As DatabaseObjects.SQL.SQLSelectTables) As DatabaseObjects.SQL.SQLSelectTableJoins Implements DatabaseObjects.IDatabaseObjects.TableJoins

    End Function

End Class


Public Class Category
    Implements IDatabaseObject

    Private pobjParent As IDatabaseObjects
    Private pintID As Integer
    Private pstrName As String

    Friend Sub New(ByVal objParent As IDatabaseObjects)

        pobjParent = objParent

    End Sub

    Friend ReadOnly Property ID() As Integer
        Get

            Return pintID

        End Get
    End Property

    Public ReadOnly Property Name() As String
        Get

            Return pstrName

        End Get
    End Property

    Public ReadOnly Property Products() As Products
        Get

            Products = New Products(NorthwindDB.Database)
            Products.Category = Me

        End Get
    End Property

    Private Property DistinctValue() As Object Implements IDatabaseObject.DistinctValue
        Get

            Return pintID

        End Get

        Set(ByVal Value As Object)

            pintID = Value

        End Set
    End Property

    Private Property IsSaved() As Boolean Implements IDatabaseObject.IsSaved
        Get
            'This function can be implemented using a boolean variable to hold
            'whether this object has been saved or not. However, if the object is
            'using an Identity field the following shortcut can be used as it is
            'logically equivalent. The Property Let IsSaved does
            'not need to be implemented

            Return pintID <> 0

        End Get

        Set(ByVal Value As Boolean)

        End Set
    End Property

    Public Sub Save()

        NorthwindDB.Database.ObjectSave(pobjParent, Me)

    End Sub

    Private Sub Load(ByVal objFields As SQL.SQLFieldValues) Implements IDatabaseObject.LoadFields

        pstrName = objFields("CategoryName").Value

    End Sub

    Private Function SaveFields() As SQL.SQLFieldValues Implements IDatabaseObject.SaveFields

        Dim objFields As SQL.SQLFieldValues
        objFields = New SQL.SQLFieldValues

        objFields.Add("CategoryName", pstrName)

        Return objFields

    End Function

End Class

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About the Author

Toby Wicks

United States United States
No Biography provided

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Web02 | 2.8.140721.1 | Last Updated 31 Jan 2007
Article Copyright 2005 by Toby Wicks
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