Click here to Skip to main content
Click here to Skip to main content
Articles » Database » Database » Databases » Downloads
 
Add your own
alternative version

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
' ___________________________________________________
'
'  � Hi-Integrity Systems 2007. All rights reserved.
'  www.hisystems.com.au - Toby Wicks
' ___________________________________________________
'

''' --------------------------------------------------------------------------------
''' <summary>
''' This class extends DatabaseObjects by storing all objects associated with this
''' DatabaseObjects collection in memory. Any objects added via VolatileObjectAdd 
''' or VolatileObjectDelete only affect the memory list until VolatileObjectsSave() is 
''' called. VolatileObjectsSave will actually delete all objects in the database
''' and then save all objects in the memory list to the database.
''' </summary>
''' --------------------------------------------------------------------------------
'''
Public MustInherit Class DatabaseObjectsVolatile
    Inherits DatabaseObjects
    Implements IEnumerable

    Private pobjParent As Object
    Private pobjItems As IList
    Private pobjItemsDeleted As IList = New ArrayList

    ''' --------------------------------------------------------------------------------
    ''' <summary>
    ''' Initializes a new DatabaseObjects with it's associated database.
    ''' </summary>
    ''' 
    ''' <param name="objDatabase">
    ''' The database that this collection is associated with.
    ''' </param>
    ''' --------------------------------------------------------------------------------
    Protected Sub New(ByVal objDatabase As Database)

        MyBase.New(objDatabase)

        pobjItems = MyBase.ObjectsList

    End Sub

    ''' --------------------------------------------------------------------------------
    ''' <summary>
    ''' Initializes a new DatabaseObjects with it's associated database.
    ''' </summary>
    ''' 
    ''' <param name="objDatabase">
    ''' The database that this collection is associated with.
    ''' </param>
    '''
    ''' <param name="objParent">
    ''' The parent collection that this collection is associated with. This is often
    ''' useful so that the SubSet property can use the Parent to filter 
    ''' by a particular value pertinent to the parent object. Using the object
    ''' is optional. 
    ''' </param>
    ''' --------------------------------------------------------------------------------
    Protected Sub New(ByVal objDatabase As Database, ByVal objParent As Object)

        MyBase.New(objDatabase)

        pobjParent = objParent
        pobjItems = MyBase.ObjectsList

    End Sub

    ''' --------------------------------------------------------------------------------
    ''' <summary>
    ''' Returns the parent object that this collection is associated with.
    ''' </summary>
    ''' --------------------------------------------------------------------------------
    Protected ReadOnly Property Parent() As Object
        Get

            Return pobjParent

        End Get
    End Property

    ''' --------------------------------------------------------------------------------
    ''' <summary>
    ''' Adds an item to the in-memory list, and flags the item to be saved to the database 
    ''' when VolatileObjectsSave() is called. 
    ''' </summary>
    ''' --------------------------------------------------------------------------------
    ''' 
    Protected Sub VolatileObjectAdd(ByVal objItem As IDatabaseObject)

        pobjItems.Add(objItem)

    End Sub

    ''' --------------------------------------------------------------------------------
    ''' <summary>
    ''' Returns an item at the specific index in the in-memory list.
    ''' </summary>
    ''' --------------------------------------------------------------------------------
    ''' 
    Protected ReadOnly Property VolatileObjectByOrdinal(ByVal intIndex As Integer) As IDatabaseObject
        Get

            Return DirectCast(pobjItems(intIndex), IDatabaseObject)

        End Get
    End Property

    ''' --------------------------------------------------------------------------------
    ''' <summary>
    ''' Removes the item from the in-memory list, and flags the item to be deleted when
    ''' VolatileObjectsSave() is called.
    ''' </summary>
    ''' --------------------------------------------------------------------------------
    ''' 
    Protected Sub VolatileObjectDelete(ByVal objItem As IDatabaseObject)

        pobjItemsDeleted.Add(objItem)
        pobjItems.Remove(objItem)

    End Sub

    ''' --------------------------------------------------------------------------------
    ''' <summary>
    ''' Firstly, all items flagged for deletion (via VolatileObjectDelete) are deleted 
    ''' in the database. 
    ''' Secondly, all items that have been added to the in-memory list (via VolatileObjectAdd)
    ''' are added/saved to the database.
    ''' </summary>
    ''' 
    ''' <example> 
    ''' <code>
    ''' Friend Sub SaveAll()
    ''' 
    '''     Mybase.VolatileObjectsSave()
    ''' 
    ''' End Sub
    ''' </code>
    ''' </example>    
    ''' --------------------------------------------------------------------------------
    ''' 
    Protected Overridable Sub VolatileObjectsSave()

        For Each objItem As IDatabaseObject In pobjItemsDeleted
            Database.ObjectDelete(Me, objItem)
        Next

        For Each objItem As IDatabaseObject In pobjItems
            Database.ObjectSave(Me, objItem)
        Next

    End Sub

    ''' --------------------------------------------------------------------------------
    ''' <summary>
    ''' Returns the number of items in the in-memory list.
    ''' </summary>
    ''' --------------------------------------------------------------------------------
    ''' 
    Protected ReadOnly Property VolatileObjectsCount() As Integer
        Get

            Return pobjItems.Count

        End Get
    End Property

    ''' --------------------------------------------------------------------------------
    ''' <summary>
    ''' Returns the enumerator for all objects currently in the in-memory list.
    ''' </summary>
    ''' --------------------------------------------------------------------------------
    ''' 
    Protected Function VolatileObjectsEnumerator() As System.Collections.IEnumerator Implements System.Collections.IEnumerable.GetEnumerator

        Return pobjItems.GetEnumerator

    End Function

End Class

By viewing downloads associated with this article you agree to the Terms of Service and the article's licence.

If a file you wish to view isn't highlighted, and is a text file (not binary), please let us know and we'll add colourisation support for it.

License

This article has no explicit license attached to it but may contain usage terms in the article text or the download files themselves. If in doubt please contact the author via the discussion board below.

A list of licenses authors might use can be found here

Share

About the Author

Toby Wicks

United States United States
No Biography provided

| Advertise | Privacy | Mobile
Web03 | 2.8.140826.1 | Last Updated 31 Jan 2007
Article Copyright 2005 by Toby Wicks
Everything else Copyright © CodeProject, 1999-2014
Terms of Service
Layout: fixed | fluid