Code Tip: Use Custom Cursors In MS Access

Using VBA in Access, apart from the Hand cursor for a Hyperlink control and using the Hourglass method of the DoCmd object, you can only use the MousePointer property of the Screen object to specify a mouse-pointer, with the cursor types limited to:

• Default Arrow
• Text Select (I-Beam)
• Vertical Resize (Size N, S)
• Horizontal Resize (Size E, W)
• Busy (Hourglass)

However, there are two API calls that allow you to use your own custom cursors or Windows system cursors in your Access applications. You can even use animated cursors.

Place the following code behind an Access form to see how the API calls work. A sample MDB is also available for download.

Option Compare Database
Option Explicit

' Declarations for API Functions
Private Declare Function LoadCursorFromFile Lib "user32" _
Alias "LoadCursorFromFileA" (ByVal lpFileName As String) As Long
Private Declare Function SetClassLong Lib "user32" Alias_
"SetClassLongA" (ByVal hwnd As Long, ByVal nIndex As Long, _
ByVal dwNewLong As Long) As Long
Private Declare Function LoadCursor Lib "user32" Alias_
"LoadCursorA" (ByVal hInstance As Long, ByVal lpCursorName As Long) As Long

' Declare Windows API Constants for Windows System cursors
Const GCW_HCURSOR = (-12)
Const IDC_APPSTARTING As Long = 32650&
Const IDC_ARROW As Long = 32512&
Const IDC_HAND As Long = 32649
Const IDC_HELP As Long = 32651
Const IDC_IBEAM As Long = 32513&
Const IDC_ICON As Long = 32641&
Const IDC_WAIT As Long = 32514&
Const IDC_UPARROW As Long = 32516&
Const IDC_SIZEWE As Long = 32644&
Const IDC_SIZENWSE As Long = 32642&
Const IDC_SIZENS As Long = 32645&
Const IDC_SIZENESW As Long = 32643&
Const IDC_SIZEALL As Long = 32646&
Const IDC_SIZE As Long = 32640&
Const IDC_NO As Long = 32648&

' Declare handles for cursor
Private Const GCL_HCURSOR = (-12)
Private hOldCursor As Long
Private hNewCursor As Long

Private Sub Form_Load()
'Load cursor
'Comment out code not required:
'Load system cursor
hNewCursor = LoadCursor(ByVal 0&, IDC_HAND)
'Load cursor from file
hNewCursor = LoadCursorFromFile(CurrentProject.Path & "\cool.cur")
'Load animated cursor from file
hNewCursor = LoadCursorFromFile(CurrentProject.Path & "\APPSTART.ani")
hOldCursor = SetClassLong(Me.hwnd, GCL_HCURSOR, hNewCursor)
End Sub

Private Sub Form_Unload(Cancel As Integer)
'Unload cursor
hOldCursor = SetClassLong(hwnd, GCL_HCURSOR, hOldCursor)
End Sub
 

Use ADO wildcards in the Access Query Design Grid

In MS Access 2000 or later, if you're using ADO, there is a way to use ADO wildcards in the Access query design grid. Instead of using the Like operator, use ALike, which also works in SQL statements used in VBA code.

All the Access Keyboard Shortcuts

70+ Keyboard shortcuts to move faster in Microsoft Access A download from TechRepublic.com.

A Better VBA Error-Handler

The undocumented VBA  constant Erl returns the line number in the procedure where an  error occurs, only if line numbers exist in the procedure:

Public Sub MyProc()
  10 On Error GoTo HandleError
  'A guaranteed error:
  20 Debug.Print 1 / 0

ExitHere:
  30 Exit Sub

HandleError:
  40 Debug.Print "Error No: " & Err.Number
  50 Debug.Print "Error Description: " & Err.Description
  60 Debug.Print "Error from Line No: " & Erl
  70 Resume ExitHere

End Sub

which returns:

Error No: 11
Error Description: Division by zero
Error from Line No: 20

in the Immediate Window.

So you now have an error-handler that returns the line number in which the error occurred!

Implementing this technique in your VBA applications, new AND existing, is easy using a great freeware Office VBA Editor add-in, MZ-Tools 3.0 VBA , which adds line numbering to a procedure in two mouse-clicks.

  Cool Tool Tips: A Better Control Tip Paradigm

In Access, the functionality of tools tips has not changed since they were introduced in Access95 ten years ago.

In a free sample Access2000 database Cool Tool Tips, which you can download, I have implemented a more functional and controllable paradigm, which also looks great.  If you have an application that is to any degree complex to use, Cool Tool Tips is an easily-implemented solution that avoids the need for a Help file, and keeps tips on the screen for however long they are needed by the user:

When a control with a tip gets the focus, the tip is read from the control's Tag property, and when the control loses the focus the tip is hidden. Clicking on the tip while it is displayed hides the tip.

A Tip's heading and text are separated by a "~" delimiter in the string assigned to a control's Tag property. The string is parsed by a generic public function in a module, called by another generic function behind the form.

Tip and Code Sample: Switching Printers from within your MS Access Application

Fellow Access develepor, Mark Plumpton, of customdata.co.nz, has kindly provided sample code for easily switching printers on the fly while printing Access reports, with code as simple as this...

   SaveDefaultPrinter
     DefaultPrinter = "HP Laserjet (A3)"
     DoCmd.OpenReport "rptTest", acViewNormal
   RestoreDefaultPrinter

Download these demo Access97/2000 databases, which include a class module that performs the function of listing and switching default printers.

The code is also an excellent example of how you can use classes in your MS Access applications.

 Create a 30 Day Demo of an MS Access Database

The object of the technique is to produce a fully protected 30 Day Demo of an Access database with the following features:

• Back-dating the system date does not overcome the 30 day trial limit
• Re-installation of the source file does not overcome the 30 day trial limit

with the caveat that no technique is hack-proof. This technique is aimed at protection against most users. Download the documentation and source code. 

Use Field Descriptions

Often overlooked is the easy way to document tables fields and automatically provide data entry guidance to users. In Table Design view, express the Description for each field as you would describe it to users making data entries. Access automatically displays the description in the Access status bar in a table's datasheet view and in forms.

Excel 2002/2003 lets you open and analyze an XML file as a native Excel file. You can use all of Excel's analysis tools, including pivot tables and pivot charts, with XML data. Use File Open, and select XML Files from the Files Of Type drop-down list. Navigate to the XML file you want to open, and click Open. Excel displays XML tags as column headings and lists the data in the rows below the appropriate column headings. For example, in an XML Orders file, every Orders element may have Ship Region as a child element. In the worksheet, Excel represents the child element as the column header /Orders/Ship Region/. Excel opens XML files as read-only files, so users can't make changes to the original file while analyzing it in Excel.

Add (All) to a LookUp Combobox

To add (All) as the first item in the droplist of an unbound combobox, replace the RowSource property with the following SQL string:

SELECT City FROM tblRegions
UNION SELECT "(All)" FROM tblRegions;

Access SQL Tip

Search for two or more single characters in a field. You can use the [ ] wildcard with the Like operator in your queries to search for two or more single characters in a field.

For example, suppose you want to find all customers with the following ZIP codes: 08052, 08053, or 08055. To use the [ ] wildcard, enter the following in your query's Criteria row under the ZIP Code field:

Like "0805[235]"

This expression searches for all field entries whose last character matches one of the characters specified between the brackets. Conversely, to search for all customers that don't live within these three ZIP code areas, place an exclamation point before the list, as shown below:

Like "0805[!235]"

The exclamation point inside the brackets stands for Not in the list. The query results will include all entries whose characters do not match any character in the list within the brackets.

You can combine the [ ] wildcard with any other wildcard character. For example, you can combine the * wildcard character with [ ] to search for any ZIP codes that begin with 0805, 0807, or 0808:

Like "080[578]*"

Give your applications a quick makeover

Globally replace MS Sans Serif font with Tahoma.

Overcome the limited color choices offered by the Format menu for the backcolor of cells in datasheets

Using VBA:

Private Sub Form_Open(Cancel As Integer)
      Me.DatasheetBackColor = 12910591 'a soft yellow
End Sub

A neat way to test both for Null or an empty string

Using the MS Access Nz function:

If Nz(Me.txtFaxNo,"") = "" Then Me.cmdSendFax.Enabled = True

MS Access Shortcut Keys for data entry:

[Shift][Enter] to save a record
[Ctrl][Alt][Spacebar] to re-instate the default value
[Spacebar] to toggle values in a check box or option
[Ctrl][;] to insert the current date
[Ctrl][Shift][;] to insert the current time
[Ctrl][+] to add a new record
[Ctrl][-] to delete the current record
[Esc] to undo a change to the current record

Private Sub txtMyName_KeyPress(KeyAscii As Integer)

If KeyAscii >= 97 And KeyAscii <= 122 Then
KeyAscii = KeyAscii - 32
End If

End Sub

Double Quotes Demystified

In string variables and when constructing SQL strings in VBA, using double-quotes can be confusing and frustrating. Try these approaches:

1. Create a global constant to represent double quotes, which makes code easier to read:

Public Const pubconQuotes = """"

Example: strSQL = "Instr(MyField," & pubconQuotes & " " & pubconQuotes & ")<>0"

2. Example: strSQL = "Instr(MyField," & chr(34) & " " & chr(34) & ")<>0"


Alternate line shading in MS Access Reports

1. Declare a constant in the Declarations of the Report's module:

Const vbLightGrey = 12632256

If Me.CurrentRecord Mod 2 = 0 Then
Me.Section(acDetail).BackColor = vbLightGrey
Else
Me.Section(acDetail).BackColor = vbWhite
End If

Keep MS Access Form Controls in Focus

It can sometimes be difficult to find the cursor on a form. To clarify which control has focus, you can configure the control to display a different background color when the user moves to it. For example, you can configure the current control to appear with a yellow background. Follow these steps:

Open the form in Design View, and select the first control.
Go to Format | Conditional Formatting.
Under Condition 1, select Field Has Focus.
Click the Fill/Back Color button, and select yellow.
Click OK.

Set this condition for each control the user will tab to; in particular, set the condition on all controls that display text, such as text boxes and combo boxes.

Compact & Repair Trick

In a database with a StartUp Form, the form will open after a Compact/Repair operation on the open .mdb. To avoid this annoyance during development, hold down the <Shift> key before clicking Compact and Repair (Access 2000 and Access 2002). In Access97, this only works for Compact Database.

Get the guid of a library reference from code

Sub AddReference()

    Dim refItem As Reference

    Set refItem = Access.References.AddFromFile _
    ("D:\Program Files\Common Files\Microsoft _
    Shared\DAO\dao360.dll")

End Sub

Since the guid is unique for every object library, for example, the guid of "Microsoft DAO 3.6 Object Library" is always {00025E01-0000-0000-C000-000000000046}, and you can obtain the guid of any object library using the above code. You can then use the .AddFromGUID method to add a reference to the object library without knowing the file path.

  Formatted MessageBox in Access 2000/2002

Function FormattedMsgBox( Prompt As String, _
Optional Buttons As VbMsgBoxStyle = vbOKOnly, _
Optional Title As String = vbNullString, _
Optional HelpFile As Variant, _
Optional Context As Variant) _
As VbMsgBoxResult

If IsMissing(HelpFile) Or IsMissing(Context) Then
    FormattedMsgBox = Eval("MsgBox(""" & Prompt & _
    """, " & Buttons & ", """ & Title & """)")
Else
    FormattedMsgBox = Eval("MsgBox(""" & Prompt & _
    """, " & Buttons & ", """ & Title & """, """ & _
    HelpFile & """, " & Context & ")")
End If

End Function

Prevent users from tabbing to the next record

Prevent users from tabbing to the next record in a form by setting the form's Cycle property to 'Current Record'.

Windows System Colors

Color ID No... Color Description

-2147483648 Scroll bar
-2147483647 Desktop
-2147483646 Active window title bar
-2147483645 Inactive window title bar
-2147483644 Menu bar
-2147483643 Window
-2147483642 Window frame
-2147483641 Menu Text
-2147483640 Window Text
-2147483639 Title bar text
-2147483638 Active window border
-2147483637 Inactive window border
-2147483636 Application background
-2147483635 Highlight
-2147483634 Highlight Text
-2147483633 3-D face
-2147483632 3-D shadow
-2147483631 Dimmed (disabled) text
-2147483630 Button Text
-2147483629 Inactive window title bar text
-2147483628 3-D highlight
-2147483627 3-D dark shadow
-2147483626 3-D light
-2147483625 ToolTip Text
-2147483624 ToolTip background
-2147483621 Active window title bar color2

Using Access 97/2000/2002 Help

Place your cursor in a keyword in a module and Hit <F>1 to open the Help file entry for that keyword. Press F2 to open the Object Browser references

Subform Shortcuts

<Tab> to move from the control immediately before the subform to the subform

<Ctrl>+<Tab> to move to the control on the main form that follows the subform *

<Ctrl>+<Shift>+<Tab> to return to the control that precedes the subform *

* If there isn't a control on the main form to move to the main form will move to the next or preceding record.

List all CommandBars in a Database

Private Sub ListMenuBars()
'Need a reference to Office Object Library

Dim cbar As CommandBar
Dim cbctl As CommandBarControl

    For Each cbar In CommandBars
        Debug.Print cbar.Name, cbar.NameLocal, cbar.Visible, cbar.Index
    Next

End Sub

Design View Shortcut

In the Access Database window, to open an object in Design view, hold down the <Ctrl> key and double-click on the object's icon.

TypeName function

The TypeName function returns a String that provides information about a variable.

Syntax: TypeName(varname)

The required varname argument is a Variant containing any variable except a variable of a user-defined type.

Public Sub CustomMessageBoxes()

Dim iResponse As Integer

MsgBox Prompt:="Abort/Retry/Ignore (Ignore Default)", Buttons:=vbAbortRetryIgnore + vbDefaultButton3
MsgBox Prompt:="Critical", Buttons:=vbCritical
MsgBox Prompt:="Exclamation", Buttons:=vbExclamation
MsgBox Prompt:="Information", Buttons:=vbInformation
MsgBox Prompt:="OK/Cancel", Buttons:=vbOKCancel
MsgBox Prompt:="Question", Buttons:=vbQuestion
MsgBox Prompt:="Retry/Cancel", Buttons:=vbRetryCancel
MsgBox Prompt:="Yes/No", Buttons:=vbYesNo
MsgBox Prompt:="Yes/No with Information", _
Buttons:=vbYesNo + vbInformation
MsgBox Prompt:="Yes/No with Critical and Help", _
Buttons:=vbYesNo + vbCritical + vbMsgBoxHelpButton

' Determine which button the user selects.
iResponse = MsgBox(Prompt:="Click Yes or No.", _
Buttons:=vbYesNo + vbCritical)
Select Case iResponse
   Case vbYes
      MsgBox Prompt:="You clicked Yes."
   Case vbNo
      MsgBox Prompt:="You clicked No."
End Select

End Sub

IIf Reloaded

For example:

• If evaluating falsepart results in a division by zero error, an error occurs even if the expression is True. In such cases, call a module-level function that uses the If... Then statement.
  
• Avoid complex calculations in one or both of the truepart and falsepart.
  

Standardise your Forms and Reports with AutoFormat

1. Design a form/report that uses your standard fonts, colors, borders, background settings, and control properties.
   
2. In Design view, from the Menubar select Format, AutoFormat... , and then in the AutoFormat Dialog click Customize...
   
3. Under Customize options in the Customize AutoFormat dialog box, select Create A New AutoFormat Based On The Form/Report and click OK. Enter a name for the standard style in the New Style Name dialog, and click OK. Click Close.
   
4. To apply the custom format to a form/report, open the form/report in Design view, select Format, AutoFormat... , then select the new format from the Form/Report AutoFormats list, and click OK.
   

Change the Default Position of Attached Labels

Access attaches a label to the left of a control by default.

To change the default position of a control's attached label you can set the left and top co-ordinates of the label using the control's Label X and Label Y properties. For example, to change the default so that the label appears to the right of a text box:

1. In Design view, double-click the form's Properties button to open the form's Properties window. In the Toolbox, click the Text Box button, to display the default Text Box properties in the Properties window. On the Format tab, change the default from -1 to 1in (or -3 to 3cm) for the Label X property.
   
2. You can also change the default position of the attached label so it is located above the text box, by setting the Label X property to 0 and the Label Y property to -0.25in (or -0.75cm).
   

Get the Name of the ActiveControl

The ActiveControl object does not have a Name property, so you need to use the Control object class:

Function GetActiveCtlName() As String
__Dim ctlCurrentControl As Control
__Set ctlCurrentControl = Screen.ActiveControl
__GetActiveCtlName = ctlCurrentControl.Name
End Function

Using the CurrentProject Object - Access 2000/2002

The CurrentProject object has several collections that contain all Access objects in the current database:

You can use these collections in code to accomplish various tasks. The following example prints the name of each open form in the AllForms collection.

Sub AllForms()
    Dim obj As AccessObject, dbs As Object
    Set dbs = Application.CurrentProject
    ' Search for open forms in the AllForms collection.
    For Each obj In dbs.AllForms
        If obj.IsLoaded = True Then
            ' Print name of obj.
            Debug.Print obj.Name
        End If
    Next obj
End Sub

Access Help provides extensive documentation on the CurrentProject object and many useful code examples.

No Data In Report?

Add this code to a Report's On No Data Event property:

Private Sub Report_NoData(Cancel As Integer)
___MsgBox "This report contains no data. Cancelling..."
___Cancel = True
End Sub

Global Keyboard Shortcuts

Menus
Show the shortcut menu	SHIFT+F10
Make the menu bar active	F10
Show the program icon menu (on the program title bar)	ALT+SPACEBAR
Select the next or previous command on the menu or submenu	DOWN or UP ARROW (with menu/submenu displayed)
Select the menu to the left or right; or, with a submenu visible, switch between the main menu and the submenu	LEFT or RIGHT ARROW
Select the first or last command on the menu or submenu	HOME or END
Close the visible menu and submenu at the same time	ALT
Close the submenu only	ESC
Toolbars
Make the menu bar active	F10
Select the next or previous toolbar	CTRL+TAB or CTRL+SHIFT+TAB
Select the next or previous button or menu on the toolbar (when a toolbar is active)	TAB or SHIFT+TAB
Open the menu(when a menu on a toolbar is selected)	ENTER
Perform the action assigned to a button	ENTER (when a button is selected)
Enter text in a text box	ENTER (when text box is selected)
Select an option from a drop-down list box or from a drop-down menu on a button	Arrow keys to move through options in the list or menu; ENTER to select the option you want (when a drop-down list box is selected)

Useful Code

Public Function RefreshLinks(strFilename As String) As Boolean
' Refresh table links to a backend database - strFilename (full path)
' Returns True if successful.

___Dim dbs As Database
___Dim tdf As TableDef

___' Loop through all tables in the database.
___Set dbs = CurrentDb
______For Each tdf In dbs.TableDefs
_________' If the table has a connect string, it's a linked table.
_________If Len(tdf.Connect) > 0 Then
____________tdf.Connect = ";DATABASE=" & strFilename
____________Err = 0
____________On Error Resume Next
____________tdf.RefreshLink ' Relink the table.
_______________ If Err <> 0 Then
__________________RefreshLinks = False
__________________Exit Function
_______________ End If
_________End If
______Next tdf

___RefreshLinks = True ' Relinking complete.

End Function

---

Function ZoomBox()

___Screen.ActiveControl.SetFocus
___RunCommand acCmdZoomBox

End Function

---

Function IsLoaded(ByVal strFormName As String) As Integer
' Returns True ifstr FormName is open in Form or Datasheet view

___Const conObjStateClosed = 0
___Const conDesignView = 0

___If SysCmd(acSysCmdGetObjectState, acForm, strFormName) <> ______conObjStateClosed Then
_________If Forms(strFormName).CurrentView <> conDesignView Then
____________IsLoaded = True
_________End If
___End If

End Function

SysCmd - A Handy Function

The SysCmd function is very useful and versatile. Look up SysCmd in the Access Help file for pointers on its use.

I recently used a feature of the function to quickly check if a nominated form was open, rather than iterate through the Forms collection. The code is set out below.

I used the following syntax:
ObjectState = SysCmd(action[, objecttype][, objectname]),
where action, is an intrinsic Access constant for a designated action.

Calling the SysCmd function with the acSysCmdGetObjectState action argument and the objecttype and objectname arguments returns the state of the specified database object. An object can be in one of four possible states: not open or non-existent, open, new, or changed but not saved.

Note If the object is either not open or doesn't exist, the SysCmd function returns a value of zero.

Public Function fnTestStartupFormLoaded() As Boolean
Dim intObjType As Integer
Dim strObjName As String
Dim intObjState As Integer

intObjType = acForm
strObjName = "frmStartUp"
intObjState = SysCmd(acSysCmdGetObjectState, intObjType, strObjName)

If intObjState <> 0 Then 'StartUpForm is loaded
   fnTestStartupFormLoaded = True
Else 'StartUpForm is not loaded
   fnTestStartupFormLoaded = False
   MsgBox "This application is not licensed for this machine." & vbCrLf _
   & vbCr & "Contact " & "the Vendor.", _
   vbCritical + vbOKOnly + vbDefaultButton1, "© MDE Copy Protector"
   Application.CloseCurrentDatabase
End If

Exit Function

End Function

A Fool-proof Way to Add a Library Reference

Those of you who develop Access add-ins or library databases, know that adding a reference to the addin or library database to the user .mdb (i.e. the CurrentDb)can be tricky, as the library file may not be where it is expected to be.

I use the following function, which is called each time the library file is loaded and uses the Name property of the CodeDb (being the library file opened by code in the CurrentDb) function to return the full path of the library file:

Private Function aad_AddLibraryReference() As Boolean
On Error GoTo AddLibraryReferenceError

Dim aad_refBuilderLibrary As Reference

Set aad_refBuilderLibrary = References.AddFromFile(CodeDb.Name)

aad_AddLibraryReference = True

Exit Function

AddLibraryReferenceError:

If Err = 32813 Then 'Reference already exists
   Resume Next
Else
   MsgBox "Add LibraryDB Reference Error" & Err & ". " & Err.Description  
   aad_AddLibraryReference = False
   Exit Function
End If

End Function

The Forms Container

Create a new module in Northwinds .mdb, insert the folllowing code (adapted from one of my addins), and run the function, which takes less than a second to do its work:

Public Function aad_fnLoadFormsList()
On Error GoTo LoadFormsListError
              
    Dim aad_db As DAO.Database
    Dim aad_con As Container
    Dim aad_edoc As Document
              
    Set aad_db = CurrentDb()
    Set aad_con = aad_db.Containers!Forms
   
    For Each aad_edoc In aad_con.Documents
        If Left$(aad_edoc.Name, 1) <> "~" Then
            Dim aad_stObjectName As String
            aad_stObjectName = aad_edoc.Name
            Debug.Print aad_stObjectName
                Dim aad_frm As Form
                Dim aad_frmCtl As Control
                Dim aad_stControlList As String
                Dim aad_intIndex As Integer
                DoCmd.OpenForm aad_stObjectName _
                ', acDesign, , , , acHidden
                Set aad_frm = Forms(aad_stObjectName)
                    For aad_intIndex = 0 To aad_frm.Controls.Count - 1
                        Set aad_frmCtl = aad_frm(aad_intIndex)
                        If TypeOf aad_frmCtl Is ComboBox Or _
                        TypeOf aad_frmCtl Is ListBox Then
                            aad_stControlList = vbTab & "Control Name: " _
                        & aad_frmCtl.Name & "; Control Source: " _
                        & aad_frmCtl.ControlSource
                            Debug.Print aad_stControlList
                        End If
                    Next aad_intIndex
                DoCmd.close acForm, aad_stObjectName, acSaveNo
        End If
    Next aad_edoc
           
    aad_fnLoadFormsList = True
   
Exit Function

LoadFormsListError:

aad_fnLoadFormsList = False
MsgBox "Load Forms Error " & Err & ". " & Err.Description
Exit Function

End Function

Use the Distribute Setting

You can evenly distribute text within  a control by setting the TextAlign property to Distribute.

Use Office XP Dialogs

Access2002 Only

Office XP has it own File Dialogs. You no longer need use API calls or the CommonDialog .ocx.

Private Sub OpenFileDialog()
___Application.FileDialog(msoFileDialogOpen).Show
End Sub

This MS KB Article will get you started: How to Display and Use the FileDialog in Access 2002

Automatically Open a ComboBox

Private Sub cboExample_GotFocus()
___Me.cboExample.Dropdown
End Sub

Size To Fit Forms

Easily size your popup forms in Access by opening the form in FormView. The form should not be maximized and the form's BorderStyle should be Resizable. Then select Window, Size To Form from the MenuBar. Save the form by pressing Ctl+s.  You can now reset the BorderStyle in need.

Compact a Database Using Jet

Function CompactDb(strSourceDB As String, strDestDB As String)

Dim jetEngine As JRO.JetEngine
Dim strSourceConnect As String
Dim strDestConnect As String

' Build connection strings for SourceConnection
' and DestConnection arguments
strSourceConnect = "Data Source=" & strSourceDB
strDestConnect = "Data Source=" & strDestDB

Set jetEngine = New JRO.JetEngine

jetEngine.CompactDatabase strSourceConnect, strDestConnect

Set jetEngine = Nothing

End Function

CommandBar Trick

This is something I recently discovered. You can add built-in Access menu commands to custom commandbars.

Normally, in the Customize dialog, if you drag a built-in menu to a custom commandbar and make changes to any if its submenu items, the changes also occur in the built-in commandbar that the menu-item comes from. To fix this, you need to reset the built-in commandbar and lose the changes in the custom commandbar.

The workaround is, after dragging the menu item to your custom commandbar:

• Drag each submenu item onto the custom commandbar.
  

• Remove the depleted menu item from the the custom commandbar.

You can now use/customize each native submenu item without affecting the native commandbar.

Resize Form Controls

You can use the InsideHeight and InsideWidth properties of an Access form to dynamically resize controls at run-time. A form's Resize event as well as firing when a user resizes a form, also fires when a form is loaded.

For example, this code will resize a sub-form within a resized form:

Private Sub Form_Resize()
On Error GoTo ResizeError

    'Turn off screen redraw  
    Application.Echo False
        Me!subfrmTest.Height = Me.InsideHeight -30      
        Me!subfrmTest.Width = Me.InsideWidth - 30
    'Turn screen redraw back on
    Application.Echo False

Exit Sub
ResizeError:

    ' NB: Turn screen redraw back on if an error occurs!
    On Error GoTo 0
    Exit Sub
       
End Sub

What's in the .ldb file

For every Access database opened for shared use, an .ldb file is created to store computer and login names, and to place extended byte range locks. The .ldb file always has the same name as the opened .mdb and is located in the same folder.

The Jet database engine uses .ldb file information to prevent users from writing data to pages that other users have locked, and to determine who has other pages locked. If Jet detects a lock conflict with another user, it reads the .ldb file to get the computer and login name of the user who has the file or record locked.

In most lock conflict situations, Access raise a generic Write conflict message that allows you to save the record, copy it to the Clipboard, or drop the changes you made. In some circumstances, you may receive the following error message:

1. In the form create a TextBox that sits exactly over the ComboBox

2. Set the ComboBox's Visible property to False

3. The TextBox is Visible and holds a value according to needs of the application: it may be a bound control or, as in the sample code below, unbound with the value assigned on the Form_Load event.

4. Clicking on the TextBox hides it and displays the ComboBox. After the user has updated the ComboBox, the value is assigned to the TextBox and the ComboBox hidden again.

Private Sub Form_Load()
    Me!txtHideShow.SetFocus
    Me!txtHideShow.Text = "Test"
End Sub

Private Sub txtHideShow_Click()
    Me!cmbHideShow.Value = Me.txtHideShow.Value
    Me!cmbHideShow.Visible = True
    Me!cmbHideShow.SetFocus
    Me!txtHideShow.Visible = False
End Sub

Private Sub cmbHideShow_AfterUpdate()
    Me!txtHideShow.Value = Me.cmbHideShow
    Me!txtHideShow.Visible = True
    Me!txtHideShow.SetFocus
    Me!cmbHideShow.Visible = False
End Sub

Get the UNC Network Path

Use the IIf Function for True-False Comparisons in Queries

The IIf function takes the following format:

IIf(Expression, TruePart, FalsePart)

Where:

• Expression is the true-false comparison that you want to make

• TruePart is the value returned if the comparison evaluates to True.

• FalsePart is the value returned if the comparison evaluates to False.

For example, a field alias value can be set as follows in the field value of a column in the Access query by design grid:

Grade: IIf([Score] < 50, "Fail", "Pass")

Quick & Easy way to check if a Table Exists

Private Function CheckIfTableExists() As Boolean
' Returns True if table exists.
   
    Dim db As DAO.Database
    Dim rst As DAO.Recordset
   
    Set db = CurrentDb

   ' Try to open table to see if it exists.
    On Error Resume Next
    Set rst = db.OpenRecordset("uztblErrorLog")

    ' If there's no error, ie. table exists, returns True.
    If Err = 0 Then
        CheckIfTableExists = True
    Else
        CheckIfTableExists = False
    End If
   
End Function

This approach can be extended to other Access objects.

Neat way to make or distribute Registry Entries/Changes

For example, the following represents a Registry entry that sets IE as an off-line browser:

REGEDIT4
[HKEY_USERS\,DEFAULT\Software\Microsoft\Windows\CurrentVersion\Internet Settings]
"GlobalUserOffline"=1

A file association in Windows allows users to double-click a .reg file and then confirm the action, and merge the contents of the file into the local registry.  So, for example, you would save the above entry in  Notepad as a .reg file, and then double-click the file in Windows Explorer to update the Registry.

Caution: Back up the registry before making any changes.

Handy User Keyboard Shortcut

To re-enter a default value in a field: [Ctrl][Alt][Spacebar].

Create a Table in Code

It is tricky creating a table in code, as some field properties are not in the default collection, for example, the Format property, and have to be created by the developer. The following procedure creates a new table and demonstrates how to add a field property if it does not exist:

Private Sub CreateLogTable()
On Error GoTo Err_CreateLogTable
 
    Dim db As DAO.Database
    Dim tdfLog As TableDef
    Dim idxLog As Index
    Dim idxLogID As Field
    Dim obj As Object
    Dim prp As Property
   
    Const conPropNotFound As Integer = 3270
   
    Dim strPathName As String
    Dim strTableName As String
    Dim strTimeFieldName As String
 
'   Open the database
    'strPathName = "database.mdb"
    'Set db = OpenDatabase(strPathName)
    Set db = CurrentDb
   
    strTableName = "tblLog"
   
'   Create the table
    Set tdfLog = db.CreateTableDef(strTableName)
   
'   Create the index field
    Set idxLog = tdfLog.CreateIndex("PrimaryIndex")
    With idxLog
        .Fields.Append .CreateField("LogID", dbLong)
        .Primary = True
        .Required = True
    End With
   
    tdfLog.Indexes.Append idxLog
    tdfLog.Indexes.Refresh
   
'   Create fields
    With tdfLog
        .Fields.Append .CreateField("LogID", dbLong)
        .Fields("LogID").Attributes = .Attributes Or dbAutoIncrField
        .Fields.Append .CreateField("LogDate", dbDate)
        .Fields.Append .CreateField("LogTime", dbDate)
        .Fields.Append .CreateField("LogFacility", dbText, 50)
        .Fields.Append .CreateField("LogName", dbText, 50)
        .Fields.Append .CreateField("LogText", dbText, 255)
        .Fields.Append .CreateField("LogReported", dbText, 255)
        .Fields.Append .CreateField("LogOutcome", dbText, 255)
    End With
   
    db.TableDefs.Append tdfLog
    db.TableDefs.Refresh
   
    With tdfLog
        strTimeFieldName = "LogDate"
        Set obj = db.TableDefs(strTableName).Fields("LogDate")
        .Fields("LogDate").Properties("Format").Value = "Short Date"
        strTimeFieldName = "LogTime"
        Set obj = db.TableDefs(strTableName).Fields("LogTime")
        .Fields("LogTime").Properties("Format").Value = "Medium Time"
    End With
   
    dbRMS.TableDefs.Refresh
 
    Set obj = Nothing
    db.Close
 
Exit_CreateLogTable:
 
    Exit Sub
   
Err_CreateLogTable:
 
     If Err = conPropNotFound Then
        ' Create property, denote type, and set initial value
       
        Dim strProperty As String
        Dim strTimeFormat As String
       
        strProperty = "Format"
        If strTimeFieldName = "LogDate" Then
            strTimeFormat = "Short Date"
        Else
            strTimeFormat = "Medium Time"
        End If
       
        Set prp = obj.CreateProperty(strProperty, dbText, _
            strTimeFormat)
       
        ' Append Property object to Properties collection
        obj.Properties.Append prp
        obj.Properties.Refresh
       
        Resume Next
       
     Else
    
        MsgBox Err.Description, vbCritical, _
            "RMS Update Server (Create tblLog)"
        Resume Exit_CreateLogTable
       
     End If
 
End Sub

Paste Controls Where You Want!

Arithmetic and Logical Operators

Arithmetic and logical operators are evaluated in the following order of precedence:

Arithmetic	Comparison	Logical
Exponentiation (^)	Equality (=)	Not
Negation (–)	Inequality (<>)	And
Multiplication and division (*, /)	Less than (<)	Or
Integer division (\)	Greater than (>)	Xor
Modulus arithmetic (Mod)	Less than or equal to (<=)	Eqv
Addition and subtraction (+, –)	Greater than or equal to (>=)	Imp
String concatenation (&)	Like
	Is

Custom Text and Memo formats

Create custom text and memo formats by using the following symbols as the Format property of fields or controls:

@  Text character (either a character or a space) is required
&  Text character is not required
<   Force all characters to lowercase
>   Force all characters to uppercase

Other Custom formats

You can use the following symbols in custom formats for any datatype:

Symbol     Meaning

(space)    Display spaces as literal characters.

"ABC"      Display anything inside quotation marks as literal characters.

!              Force left alignment instead of right alignment.

*             Fill available space with the next character.

\             Display the next character as a literal character. You can
              also display literal characters by placing quotation marks
              around them.

[color]    Display the formatted data in the color specified between the
              brackets. Available colors: Black, Blue, Green, Cyan, Red,
              Magenta, Yellow, White.

NB: When you have defined an input mask and set the Format property for the same datatype, the Format property takes precedence when data is displayed and the input mask is ignored.

Input Mask Characters

You can define an input mask by using the following characters:

Character    Description

0                  Digit  (0 to 9, entry required, plus [+] and minus [–] signs not allowed)

9                  Digit or space (entry not required, plus and minus signs not allowed)

#                  Digit or space (entry not required; spaces are displayed
                    as blanks while in Edit mode, but blanks are removed
                    when data is saved; plus and minus signs allowed)

L                  Letter (A to Z, entry required)

?                  Letter (A to Z, entry optional)

A                  Letter or digit (entry required)

a                  Letter or digit (entry optional)

&                  Any character or a space (entry required)

C                  Any character or a space (entry optional)

.  ,  :  ;  -  /     Decimal placeholder and thousand, date, and time
                    separators. (The actual character used depends on the
                    settings in the Regional Settings Properties dialog box in
                    Windows Control Panel)

<                  Causes all characters to be converted to lowercase

>                  Causes all characters to be converted to uppercase

!                   Causes the input mask to display from right to left, rather
                    than from left to right. Characters typed into the mask
                    always fill it from left to right. You can include the
                    exclamation point anywhere in the input mask.

\                  Causes the character that follows to be displayed as a
                    literal character (for example, \A is displayed as just A)

Search for "InputMask Property" in Access Help for more information.

Save the Trees: Use Multi-Column Reports

To create a multi-column report:

1. In Report Design View, select <File>, <Page Setup...>  from the Menubar
2. Select the Columns tab in the Page Setup dialog
3. Enter the number of columns
4. Optionally, set the row and column spacing properties
   
5. Enter the width of each column
6. Select  the Column Layout, and click OK.
   

Find Installed Versions of Access

The following code finds which currently MS supported versions of Access
(ie. 97/2000/2002), if any, are installled using the Word.Application object. The code can be used in any Office application or a VB executable.

Public Function OfficeDir(OffVer As String) As String
On Error GoTo ErrorTrap
   
   Dim objWord As Object
 
   Set objWord = CreateObject("Word.Application")
  
   Select Case OffVer
        Case "acc97"
            OfficeDir = objWord.System.PrivateProfileString("", _
            "HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Office\8.0", _
              "BinDirPath") & "\msaccess.exe"
              'Debug.Print OfficeDir
        Case "acc2k"
            OfficeDir = objWord.System.PrivateProfileString("", _
          "HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Office\9.0\Access\InstallRoot", _
              "Path") & "msaccess.exe"
              Debug.Print OfficeDir
        Case "accxp"
            OfficeDir = objWord.System.PrivateProfileString("", _
            "HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Office\10.0\Access\InstallRoot", _
              "Path") & "msaccess.exe"
              Debug.Print OfficeDir             
        Case Else
   End Select
  
   objWord.quit
   Set objWord = Nothing
 
Exit Function
ErrorTrap:
 
    objWord.Close
    Set objWord = Nothing
    MsgBox "Error " & Err & ". " & Err.Description & ".", vbCritical
    Exit Function
  
End Function

Create a Default Control

Check for Run Time Access

Function IsRunTime() As Boolean

Dim varReturn As Variant

    'Returns True (-1) if a run-time version of Access is running
    varReturn = SysCmd(acSysCmdRuntime)

    IsRunTime = varReturn

End Function

VBA Tips

Use Early Binding
When using object variables, wherever possible, declare the actual type of object instead of the generic Object variable to take advantage of the performance gains provided by early binding.

For example, Dim frm as Form instead of Dim frm As Object.

Use For Each... Next
When going through object collections, using For Each.. Next is much faster than using For... Next.

Using For Each.. Next, VBA needs to locate the address of the object variable only once, at the beginning of the loop, while For... Next de-references the object variable in the body of the loop on each iteration.

Use the Nz function to convert null to zero

In this example from the Access97 Help file, the NZ function converts a null value to zero, and the optional argument provides the string to be returned if varFreight is Null:

___varResult = Nz(varFreight, "No Freight Charge")

Search for Nz Function in Access Help for more information.

Get the Description for an Error Number

Use the AccessError method of the Application. object to return the descriptive string associated with an Access or DAO error:

___strstrErrorString = AccessError(lngError)

Dialog Shortcuts

Select a folder in the Open or Save As dialog box (File menu) (to select the folder list; arrow keys to select a folder)	ALT+0
Choose toolbar button in Open or Save As dialog box (File menu)	ALT+ number 1 is the leftmoist, 2 the next, and so on
Update files visible in the Open or Save As dialog box (File menu)	F5
Switch to next tab	CTL+TAB or CTL+PageDown
Switch to the previous tab	CTL+SHIFT +TAB or CTL+PageUp
Perform the action assigned to the default button	ENTER

Find Out if a Windows Application is Open

Option Compare Database
Option Explicit

'Use the API function FindWindow to determine whether an application is already running.
'Useful for OLE automation.
Declare Function FindWindow Lib "user32" Alias " FindWindowA" _
(ByVal lpClassName As String, ByVal lpWindowName As String) As Long

'Custom Declare statement that uses the FindWindow API call
'to find a window of the specified class.
'Pass a long NULL pointer for the window name.
Declare Function FindWindowByClass Lib "user32" Alias "FindWindowA" _
(ByVal lpClassName As String, ByVal lpWindowName As Long) As Long

'Class names for some common applications:
'Access: OMain
'Excel: XLMAIN
'Word: OpusApp
'PowerPoint: PP97FrameClass
'Visual Basic: ThunderForm
'Binder: BinderFrame
'Visio: VisioA

Dim mblnRetVal As Boolean

'Example: find Word.
Public Function fnFindMSWord() As Integer

___Dim lngRetVal As Long
___Dim strMSG As String

___lngRetVal = FindWindowByClass("OpusApp", 0&)
___If lngRetVal <> 0 Then ' Word already open
______fnFindMSWord = True
___Else ' Word not open
______fnFindMSWord = False
End If

End Function

Determine the Caption of an Attached Label in Code

Use this simple VBA code to find the caption of a label attached to a control on a form or report:

Dim ctl As Control
Set ctl = Me.txtOrderID
Debug.Print ctl.Controls.Item(0).Caption

An Easy Way to Register a .dll Using Regsvr32.exe

Open two Windows Explorer windows - one window displaying the .dll and the other Regsvr32.exe. Now drag Regsvr32.exe over the .dll, and presto the .dll is registered!

Keyboard Shortcuts for Running and Debugging Code

To display the Debug window CTL+G To run a parameterless subprocedure containing the insertion point, from the Module window F5 To switch between the upper and lower panes F6 To step into a procedure (single step) F8 To step over a procedure SHIFT+F8 To step out of a procedure CTL+SHIFT+F8 To run code to the current insertion point and halt execution CTL+F8 To create an instant watch for a selected expression SHIFT+F9 To toggle a breakpoint at the selected line F9 To clear all breakpoints CTL+SHIFT+F9 To set the next statement CTL+F9 To continue the execution of code or a macro F5 To halt execution of code or macro CTL+BREAK To reset execution of code or macro F5 To reset execution of code or macro SHIFT+F5 To toggle between breaking and not breaking on unhandled errors and then step to the next statement ALT+F5 To toggle between breaking and not breaking in class modules and then continue execution ALT+F8

Run A Word MailMerge from Access

Copy and paste into a new Access module:

Option Compare Database
Option Explicit

Function MergeIt(stFilePath As String, stQuery As String)
Paramaters:
stFilePath As String - Full path to merge letter template
stQuery As String - SQL String for merge fields data from the CurrentDB

Dim stDBName As String
Dim objWord As Word.Document
Dim stSQL As String

stSQL = "Select * from " & stQuery & ""
stQuery = "QUERY " & stQuery

stDBName = CurrentDb.Name

Set objWord = GetObject(stFilePath, "Word.Document")

' Make Word visible.
objWord.Application.Visible = True

' Set the mail merge data source as the Northwind database
objWord.MailMerge.OpenDataSource _
Name:=stDBName, _
LinkToSource:=True, _
Connection:=stQuery, _
SQLStatement:=stSQL

' Execute the mail merge.
objWord.MailMerge.Execute

End Function

Effective Access Security

To effectively secure an Access database you MUST demote the Admin user from the Admins group. Otherwise your database will not be secure, as Admin cannot be removed from the Users group, and anyone using the retail system.mdw logs on automatically as Admin.

Securing An Access Database

1. Use the Access Workgroup Administrator (AWA), wrkgadm.exe, to create a new workgroup (.mdw) file.

2. Join the new workgroup using AWA.

3. Open Access and the database to be secured.

4. Using Tools, Security, User and Group Accounts..., in the User and Group Accounts dialog:

        4.1 Create a password for Admin user.

        4.2 Create a new user account. This account will be the new
        database owner account. In sample.mdw, this owner account
        is called DBOwner. Add "DBOwner" to all groups, including the
        critical Admins group.

5. Close and re-open Access, logging on as "DbOwner", and leaving the password blank, as you have not assigned one yet.

7. In the User and Group Accounts dialog, demote the Admin user account by removing it from the Admins group. Now Admin is only a member of the Users group and will have only those permissions assigned to that group by "DBOwner".

8. Create a password for "DBOwner".

9. Close and re-open Access, logging on as "DBOwner" using the password you created in step 8.

10. You can now start to secure the objects in you database.

Special Notes:

• A User account inherits the permissions of the Group to which it belongs.
  
• In Acess2000 and later, if you are not creating an .mde, you also need to secure your code by using Password Protection in the VBA Editor.

Handy Date and Time Functions

The current month	DateSerial(Year(Date()), Month(Date()), 1)
The next month	DateSerial(Year(Date()), Month(Date()) + 1, 1)
The last day of the current month	DateSerial(Year(Date()), Month(Date()) + 1, 0)
The last day of the next month	DateSerial(Year(Date()), Month(Date()) + 2, 0)
The first day of the previous month	DateSerial(Year(Date()), Month(Date())-1,1)
The last day of the previous month	DateSerial(Year(Date()), Month(Date()),0)
The first day of the current quarter	DateSerial(Year(Date()), Int((Month(Date()) -1) / 3) * 3 + 1, 1)
The last day of the current quarter	DateSerial(Year(Date()), Int((Month(Date()) -1) / 3) * 3 + 4, 0)
The first day of the current week (assuming Sunday = day 1)	Date() - WeekDay(Date()) + 1
The last day of the current week	Date() - WeekDay(Date()) + 7
The first day of the current week (using settings in Options dialog box)	Date() - WeekDay(Date(), 0) + 1
The last day of the current week	Date() - WeekDay(Date(), 0) + 7

Check the Access Version in Code

SysCmd(acSysCmdAccessVer) = 8 'Access97

SysCmd(acSysCmdAccessVer) = 9 'Access2000

SysCmd(acSysCmdAccessVer) = 10 'Acess2002

Improve Subform Performance

• Base subforms on queries rather than tables. Include only required fields from the record source.
• Index all the fields on the subform that are linked to the main form. Indexes speed up the matching of subform records.
• Index any fields used for criteria such as where a subform is based on a parameter query.
• If you are linking on multiple fields, add a calculated field to the main form that concatenates the fields. Then, create a calculated column in the subform's RecordSource property query with the same expression.
  
  For example, to link to the subform on an Employee ID field and an Order ID field, add a text box to the main form with the following properties:
  
  Name: EmployeeIDOrderID
  ControlSource: =[EmployeeID] & [OrderID]
  
  Next, add the following field to the query that the subform is based on:
  
  EmployeeIDOrderID: [Employee ID] & [Order ID]
  
  Then, link the main form and the subform on the concatenated field rather than on the two individual fields. The subform properties might look as follows:
  
  LinkChildFields: EmployeeIDOrderID
  LinkMasterFields: EmployeeIDOrderID
  
  Because Access only has to compare one criteria to return the subform's recordset, the subform's performance should improve.
• Set the subform's DefaultEditing property to Read-Only if the records in the subform are not going to be edited.
• If your subform is a continuous form and contains combo boxes, explicitly justify the combo box in the subform's form Design view. This prevents Access from determining the proper justification of the combo box values for each record and thus speeds the display of subform records which have combo boxes.

Useful API Functions

Copy and paste into a new Access module:

Option Compare Database
Option Explicit

'This prevents screen redraw. It's especially handy
'when using OLE automation.
Declare Function LockWindowUpdate Lib "user32" _
(ByVal hwndLock As Long) As Long

'This is a custom Declare statement that uses the FindWindow API call
'to find a window of the specified class. Pass a long NULL pointer
'for the window name.
Declare Function FindWindowByClass Lib "user32" Alias "FindWindowA" _
(ByVal lpClassName As String, ByVal lpWindowName As Long) As Long

'API Function that Points to a RECT structure that receives the screen
'co-ordinates of the upper-left and lower-right corners of a window.
Private Declare Function GetWindowRect Lib "user32" _
(ByVal hwnd As Long, lpRect As RECT) As Long

Private Type RECT

Left As Long
Top As Long
Right As Long
Bottom As Long

End Type

'API Function to get Screen Resolution
Declare Function GetSystemMetrics Lib "user32" _
(ByVal nIndex As Integer) As Integer

Public Function fnGetApplicationWindowHeight() As Long

Dim hwnd As Long
Dim lngRetVal As Long
Dim hwndPrevious As Long

'Get the handle to this Access window.
hwnd = FindWindowByClass("OMain", 0&)

Dim Rec As RECT

'API uses pixels
' Get Left, Right, Top and Bottom of Access Application Window

GetWindowRect hwnd, Rec

fnGetApplicationWindowHeight = Rec.Bottom - Rec.Top

End Function

Public Function IsVGA() As Boolean

Dim xRes As Integer
Dim yRes As Integer

IsVGA= False

xRes = GetSystemMetrics(0)
yRes = GetSystemMetrics(1)

If xRes < 800 And yRes < 600 Then ' is vga
IsVGA= True
Else
IsVGA= False
End If

End Function

Public Function fnEcho(intFlag As Integer)

Dim hwnd As Long
Dim lngRetVal As Long
Dim hwndPrevious As Long

Select Case intFlag

'Echo OFF
Case 0
'Get the handle to this Access window
hwnd = FindWindowByClass("OMain", 0&)

'Prevent updates to this window
lngRetVal = LockWindowUpdate(hwnd)

'Echo ON
Case 1
lngRetVal = LockWindowUpdate(0&)

End Select

End Function

Handy Shortcuts

• In a module, when using IntelliSense, press <Ctrl>+<Shift>+<J> to display/redisplay the relevant arguments/constants.
  
• When coding the constants for the MsgBox function, hit the + key to add constants to the buttons argument.

XP Icons

In WinXP, get XP-style icons from the file, shell32.dll, in the /System32 folder, using a freeware app like Icon Sucker.

Weekday Date Validation

This validation rule limits entries to weekdays:

DatePart("w",[HireDate],7)>2

The DatePart function returns a number from 1 to 7, corresponding to the days of the week. A Saturday date returns 1, and a Sunday date returns 2. Therefore, checking for a value that's greater than 2 eliminates any entry that equals 1 or 2.

Speed up your Access 2000 Forms

A tip from Mark Plumpton of www.customdata.co.nz

I have a form that took 85 seconds to save. After applying the technique below it reduced the save time to just a couple of seconds. It also reduced my compacted database size from 5mb to 4mb after applying this technique.

This is the tip: Load the form, subform, combobox and listbox record sources at run-time. That's it. You will achieve dramatic performance improvement and reduced database size.

Here's the technique: Delete the SQL from the RecordSource and RowSource properties of the form, subforms, comboboxes and listboxes. Now in the Form_Load event load the appropriate SQL as follows ...

Private Sub Form_Load()
    Me.RecordSource = "qryLargeTable"
    Me.txtSomeField.RowSource = _
        "SELECT SomeField " & _
        "FROM qryLargeTable " & _
        "GROUP BY SomeField " & _
        "ORDER BY SomeField;"
End Sub

It also pays to clear the record sources in the Unload event as sometime these get saved with the form in Access 2000.

Private Sub Form_Unload(Cancel As Integer)
    Me.RecordSource = ""
    Me.cboFindRecord.RowSource = ""
End Sub

Insider Code

Thanks to Jacques Soudan of www.troisj.com for this compilation of undocumented constants for the SysCmd function:

SysCmd(7) 'Detects the Access VERSION number

For Access 97:

SysCmd 603, PathMdb, PathMde 'convert MDB -> MDE
SysCmd 602, PathMdb, PathMdb 'compact DB
SysCmd 555 'create MSysIMEX... tables
SysCmd(504, 16483) 'save and compile code
SysCmd(504, 16484) 'save code without compiling
SysCmd(501, i) 'list of references, i = 0, 1, ... n
SysCmd(500) 'count of references

For Access 2000+:

SysCmd 603, PathMdb, PathMde 'convert MDB -> MDE
SysCmd 602, PathMdb, PathMdb 'compact DB
'You must use in this case following method, example:
    Dim accApp As Access.Application
    Set accApp = New Access.Application
    accApp.SysCmd 603, PathMdb, PathMde
    accApp.SysCmd 602, PathMdb, PathMdb
    Set accApp = Nothing
SysCmd(605, 0) 'convert DB to previous version
SysCmd(605, "C:\Database97.mdb") 'convert DB to previous version
SysCmd(607,"C:\Project1.adp") 'convert DB to ADP project
SysCmd(608, i) '60 tips about Access programming for i=0, 1, ... 60
SysCmd(710, 68486165) 'set Polish keyboard (if installed)
SysCmd(710, 67699721) 'set US keyboard
SysCmd(710, 68748313) 'set Russian keyboard
SysCmd(710, 67634184) 'set Greek keyboard
SysCmd(710, ...) 'set other country keyboard
SysCmd(710,1) 'set next installed keyboard
SysCmd(710,0) 'set previous installed keyboard
SysCmd(711) 'return put keyboard currently
SysCmd(714) 'returns TRUE, if any form, report, macro or module is in design mode
SysCmd(715) 'returns Build number of MSACCESS.EXE file to check Access version or e.g. which Service Pack is installed.

Extra Tips

• When writing code for controls in Access Form or Report Design View, save keystrokes by, in the Events tab of the Properties Dialog, typing "[" in the selected event and then clicking the adjacent build button, to bring you straight into the selected event procedure in the VBA editor.
  
• In Access Form or Report Design View, to attach a linked control label to an orphan control, copy the linked label from an existing control, then select the orphan control and paste the label, which will attach itself to the orphan control.
  
• To easily copy an icon from an Access toolbar button, right-click on the Toolbar, and select Customize..., then right-click on the button and select Copy Button Image, and paste the image as required.
  
• In Access97 only, create a nicely formatted Message Box using VBA code like this:
  
  MsgBox "Heading Text@Body Text@Footer Text"

Access Databases on a Network

Generally, Access can handle up to 50 concurrent users over a network without any trouble, but there are other issues to consider:

• Does the server and do the client PCs have enough grunt?
• Is LAN broadband sufficient?
• How big is the database?
• How is it split? 
• Keep administrative functions in the back-end
• Locate all lookup tables and those with static data in the front-end
• How is the back-end queried?   Are you using ODBC, JET, DAO, or ADO etc...?
• Don't open tables across the network. Locate back-end queries in the back-end
• Open queries with the minimum recordset required. Use Snapshots where possible
• What RecordLocking regime is in place ...optimistic, pessimistic... ?
• Your level of experience with and knowledge of Client/Server databases. The Chapter Building Client/Server Applications in the Access documentation, Building Applications with Microsoft Access, is a good starting point.  

Visual Basic and Access Development

When searching the Web for code samples and guidance in Access, don't ignore Visual Basic sites, as they are a great source of useful code, free type libraries, free .ocx's and information for Access and Office Developers.

Reset AutoNumber in a Table

To create a new empty table and reset the AutoNumber field from an existing data table:

1. rename the existing table as "x_tblData", and
2. open x_tblData in Design View and save as "tblData" using File, Save As.

Use API Calls to determine Windows and Systems Directories
Source: Christine Solomon, Microsoft Office Developer's Handbook,
Microsoft Press,1997

Option Compare Database 'Use database order for string comparisons
Option Explicit

'To get a string from an API function, you need to pass the function
'a string buffer (a variable for storing the string retrieved), and
'an integer specifying the length of the string buffer.
'You must ensure that this buffer is big enough to hold the whole
'string. One way to do this is to use the String$() function to create a
'"space" holder of the maximum length you'll need + 1 to accommodate
'the null character that terminates strings.

'Gets the Windows directory.
Declare Function GetWindowsDirectory Lib "kernel32" _
Alias "GetWindowsDirectoryA" (ByVal lpBuffer As String, _
ByVal nSize As Long) As Long

'Gets the Windows\System directory.
Declare Function GetSystemDirectory Lib "kernel32" _
Alias "GetSystemDirectoryA" (ByVal lpBuffer As String, _
ByVal nSize As Long) As Long

Sub devGetWindowsDirectory()

Dim strBuffer As String
Dim intLen As Integer

'Provide strBuffer enough space to hold the path.
'String$() returns a repeating character string of
'the length specified.
strBuffer = String(256, 0)

'Copy the path into strBuffer. Len(strBuffer) is simply a more
'portable way of providing the length of the buffer than hardcoding
'a number.
intLen = GetWindowsDirectory(strBuffer, Len(strBuffer))

'Trim strBuffer down to the path's actual size.
strBuffer = Left(strBuffer, intLen)

'Display the path in a message box.
MsgBox strBuffer, vbInformation, APP_NAME

End Sub

Sub devGetSystemDirectory()

Dim strBuffer As String
Dim intLen As Integer

'Provide strBuffer enough space to hold the path.
'String$() returns a repeating character string of
'the length specified.
strBuffer = String(256, 0)

'Copy the path into strBuffer. Len(strBuffer) is simply a more
'portable way of providing the length of the buffer than
'hardcoding a number.
intLen = GetSystemDirectory(strBuffer, Len(strBuffer))

'Trim strBuffer down to the path's actual size.
strBuffer = Left(strBuffer, intLen)

'Display the path in a message box.
MsgBox strBuffer, vbInformation, APP_NAME

End Sub

Get The Current Directory

CurrentDB.Name returns the full path. Use the following code to return just the directory:

Dim stDBPath As String, strDBDirectory As String
stDBPath = CurrentDb.Name
strDBDirectory = Left(stDBPath, Len(stDBPath) - Len(Dir(stDBPath)))

Create a Hybrid Text/ComboBox

1. In the form create a TextBox that sits exactly over the ComboBox

2. Set the ComboBox's Visible property to False

3. The TextBox is Visible and holds a value according to needs of the application: it may be a bound control or, as in the sample code below, unbound with the value assigned on the Form_Load event.

4. Clicking on the TextBox hides it and displays the ComboBox. After the user has updated the ComboBox, the value is assigned to the TextBox and the ComboBox hidden again.

Private Sub Form_Load()
    Me!txtHideShow.SetFocus
    Me!txtHideShow.Text = "Test"
End Sub

Private Sub txtHideShow_Click()
    Me!cmbHideShow.Value = Me.txtHideShow.Value
    Me!cmbHideShow.Visible = True
    Me!cmbHideShow.SetFocus
    Me!txtHideShow.Visible = False
End Sub

Private Sub cmbHideShow_AfterUpdate()
    Me!txtHideShow.Value = Me.cmbHideShow
    Me!txtHideShow.Visible = True
    Me!txtHideShow.SetFocus
    Me!cmbHideShow.Visible = False
End Sub

Show SubForm in Datasheet View AND Back Again:

You know that by right-clicking in a subform that is in Form View, you can click Subform Datasheet in the Subform's right-click PopUp Shortcut Menu to switch the Subform to Datasheet View, but you can't restore Form View for the Subform without closing and then re-opening the main form. There is a nice work-around which I recently discovered:

1. Open a Form with a Subform.

2. Display the Toolbar to be used with that Form, and right-click on that Toolbar, then click Customize...

3. In the Customize Toolbars Dialog, in the Toolbars tab, scroll to the bottom of the Toolbars listbox, and tick Shortcut Menus to display the ShortCuts CommandBar.

4. In the ShortCuts CommandBar, click on Form, then Form View Subform.

5. Drag the Subform Datasheet item in the Form View Subform submenu onto the form's Toolbar.

6. IMPORTANT - Immediately click the Reset button on the Customize Toolbars dialog to re-instate the Subform Datasheet item in the ShortCuts CommandBar. Close the ShortCuts CommandBar.

7. The new toolbar button on the main form's Toolbar will be blank.

8. Locate the Datasheet View Toolbar Button on the Form View Toolbar, right-click on it, and click Copy Button Image.

9. Right-click on the new toolbar button on the main form's Toolbar, and click Paste Button Image. The new toolbar button will now sport the Datasheet View icon.

10. Close the Customize Toolbar dialog.

11. Now place your cursor/mouse in the subform. Clicking on your new toolbar button will switch the subform to Datasheet View, but you will also notice that the button is a toggle button and that is in its pressed state. Click on it to restore it and presto the subform reverts to Form View!

A Pre-Deployment Checklist for Access Projects: 

1. Remove Redundant References

2. Check Tab Order in Forms

3. Check Status Bar and ToolTips Text

4. Check Security:

___4.1 If an unsecured .mde, remove Admin design permissions for tables/queries from the .mde

___4.2 If an Access2000 or later .mde, secure VBA code

5. Check Error Handling

Useful Access Keyboard Shortcuts

• ctl+' ___Enter same entry for the current field as the previous record
• ctl+: ___Enter current date in current control

Work in both form and datasheet views.

Access2002 and Access2000 Revisited

Further to last month's piece, some further advice for those with Access2000 installed on a PC with Access2002. Always allow completion of the Access2000 Windows Installer. Pressing Cancel will not reset the Windows Registry entries for Access, and Access2000 will incorrectly reference the Access 10.0 library, leading to problems if you distribute an Access2000 .mde compiled with this incorrect reference.

Quickly Save a Web Page in IE

Before clicking Save As, click Work Offline - IE will go offline WITHOUT CLOSING YOUR INTERNET CONNECTION. The page will save in the fraction of the time required if IE is Online. When you next click on a link, you will be prompted to go back Online.

Audit Trail for Table Records

In a Data Form:

Private Sub Form_BeforeUpdate(Cancel As Integer)

'Purpose: Timestamp current form record
'Field Controls:
'LastEdit - General Date DataType
'DateAdded - General Date DataType
'CreatedBy - Text DataType
'LastEditBy - Text DataType

On Error GoTo RecStamp_Error

Me.LastEdit = Now
Me.LastEditBy = GetUser()

' Only stamp DateAdded and CreatedBy fields if a new record
If Me.NewRecord Then
___Me.DateAdded = Now
___Me.CreatedBy = GetUser()
End If

RecStamp_Exit:

Exit Sub

RecStamp_Error:

MsgBox Err.Description
Resume RecStamp_Exit

End Sub

In a Code Module:

Option Compare Database
Option Explicit

Public Declare Function GetUserName _
Lib "Advapi32.dll" Alias "GetUserNameA" _
(ByVal ABuffer As String, nSzie As Long) As Long

Public Function GetUser() As String
'Returns Windows User LogOn ID
On Error GoTo GetUser_Err

Dim sUserName As String
Dim lSize As Long
Dim lLength As Long

sUserName = String(15, " ")
lSize = Len(sUserName)
lLength = GetUserName(sUserName, lSize)
GetUser = Left(sUserName, lSize - 1)

Exit Function
GetUser_Err:

GetUser = "Unknown"
Exit Function

End Function

  Handy Functions - look up the details in your Access Help file:

• SysCmd

• IsDate
• IsNumeric
• InString
• AutoLookup
• DCount

How to refer to a control on a subform from the parent form:

Me.txtTotal.Value = Me.OrdersSubForm.Form!txtOrderTotal

Stop the Web Toolbar appearing when users click a hyperlink in an Access form. Place the following code in the hyperlink's Click_Event:

DoCmd.ShowToolbar "Web", acToolbarNo

Tips for Faster Queries:

• Compact your database often.
• When you join tables, try to index the fields on both sides of a join.
• If you use criteria to restrict the values in a field used in a join,the query may run faster if the criteria is added to the field on the "one" side of the join instead of the "many" side.
• When creating a query, add only the fields you need. In fields used to set criteria, clear the Show checkbox if those fields are not displayed.
• Avoid restrictive criteria on calculated and non-indexed columns.
• Avoid calculated fields in nested queries.
• When grouping records by the values in a joined field, specify Group By for the field that is in the same table as the field you are totalling.
• Use Group By on as few fields as possible.

Recover a corrupt database

If you are encountering database corruption, you can perform the following steps:

1. Export all form objects in the database to text files using the following procedure:

Application.SaveAsText(acForm, "<Form>", "<Path and File Name>")

where <Form> is the name of an existing form object, and <Path and File
Name> is the path to and the file name of the text file to be created.

2. Create a new database.

3. Import all the database objects (except form objects) into the new
database:

a. With the new database open, point to Get External Data on the File menu, and then click Import.

b. In the Import dialog box, locate and then click the damaged database, and then click Import.

c. On the Tables tab in the Import Objects dialog box, click Select All. Repeat this step for each type of object except the form object.

d. Click OK to import the selected objects.

4. Import each of the exported text files to the new database by using the following procedure:

Application.LoadFromText(acForm, "<Form>", "<Path and File Name>")

where <Form> is the name of the form object, and <Path and File Name> is the path to and the file name of the text file to be imported.

For more info about database corruption, refer to this MSDN article:

Q209137 ACC2000: How to Troubleshoot/Repair a Damaged Jet 4.0 Database
http://support.microsoft.com/default.aspx?scid=kb;EN-US;Q209137

Split the Module Window

You can split the Access module window into two scrollable panes. Drag the split box (the small rectangle that's directly above the vertical scroll bar) to where you want the split made. To remove the split, double-click on the split line.

Use DoCmd.PrintOut to set Printer Options

Using the PrintOut method of the DoCmd object method provides a convenient way to fill in the options in the Print dialog box. Place a function in a report's On Detail Format event:

Private Sub Detail_Format(Cancel As Integer, FormatCount As Integer)

___Dim rpt as Report
___Dim strMessage As String
___Dim intHorSize As Integer, intVerSize As Integer

___Set rpt = Me
___strMessage = "DisplayMessage"

___'Set scale to pixels, and set FontName and FontSize properties.
___With rpt
______.ScaleMode = 3
______.FontName = "Courier"
______.FontSize = 24
___End With

___' Horizontal width.
___intHorSize = Rpt.TextWidth(strMessage)

___' Vertical height.
___intVerSize = Rpt.TextHeight(strMessage)

___' Calculate location of text to be displayed.
___Rpt.CurrentX = (Rpt.ScaleWidth/2) - (intHorSize/2)
___Rpt.CurrentY = (Rpt.ScaleHeight/2) - (intVerSize/2)

___' Print text on Report object.
___Rpt.Print strMessage

End Sub

Revert Command in Access 2000/2002

If you have made changes in design view to a form or report, and then want to discard the changes, click File from the main menubar, then Revert. The Revert command restores the form or report to the state it was in before you started the current editing session.

One less mouse-click :)

Jump straight to the module window from a [...] builder button and by-pass the Expression/Macro builders.

Select Tools/Options from the main menubar, click on the Forms/Reports tab, then select the Always Use Event Procedures check box, and click OK.

Easy Commenting -  Access 2000/2002

In the Visual Basic Editor, select View/Toolbars/Edit from the menubar to display the Edit Toolbar, which has some useful shortcuts. For example, you can easily comment/uncomment a block of code. Highlight the code block, then click the Comment Block button on the Edit Toolbar. To uncomment back to executable code, select the code lines and click the Uncomment Block button.

New Access 2002 Shortcuts

F4 In Design view, opens the properties sheet

F7 When a form or report is open in Design view (with the focus on the Design view window or a properties sheet), takes the user to the code window, open to the form or report code module

Shift+F7 When the focus is on a properties sheet in Design view, moves the focus back to the design area without closing the properties sheet

F8 In a form or report in Design view, opens the field list; in a data access page in Design view, toggles the field list on or off

Ctrl+Right Arrow Moves to the next view when you’re working with tables, queries, forms, reports, pages, views, and stored procedures

Ctrl+Left Arrow Moves to the previous view when you’re working with tables, queries, forms, reports, pages, views, and stored procedures

Ctrl+Tab Navigates from a form or report section to a subsection

Enter In Design view, with a field selected in the field list in a form or report, adds the selected field to the form or report design surface
 

Determine the Disk Drive Type
 

Public Declare Function GetDriveType Lib "kernel32" Alias _
"GetDriveTypeA" (ByVal nDrive As String) As Long

Const DRIVE_REMOVABLE = 2
Const DRIVE_FIXED = 3
Const DRIVE_REMOTE = 4
Const DRIVE_CDROM = 5
Const DRIVE_RAMDISK = 6

The function's argument is a string identifying the drive's root folder. The return value is one of the contants declared above, depending on the drive type. If any other value is returned, the drive was not recognized.

The following procedure illustrates the use of this API function. The argument must be in the form required by the GetDriveType function: the drive letter followed by ":\".

Private Sub DriveType(dr as string)

___Dim dr As String
___Dim drivetype as Long

___drivetype = GetDriveType(dr)

___Select Case drivetype
______Case DRIVE_REMOVABLE:
_________MsgBox "Drive " & dr & " is a removable drive"
______Case DRIVE_FIXED:
_________MsgBox "Drive " & dr & " is a fixed (hard) drive"
______Case DRIVE_REMOTE:
_________MsgBox "Drive " & dr & " is a remote (network) drive"
______Case DRIVE_CDROM:
_________MsgBox "Drive " & dr & " is a CD-ROM drive"
______Case DRIVE_RAMDISK:
_________MsgBox "Drive " & dr & " is a RAM drive"
______Case Else:
_________MsgBox "Drive " & dr & " was not recognized"
___End Select

End Sub
 

Calculate Time Totals

'---------------------------------------------------
' This function accepts a time interval and returns
' a value, such as "55:23" for 55 hours and 23 minutes.
'---------------------------------------------------

Function HoursMinutes(Hour As Variant) As Variant
Dim Hrs As Long, Mins As Integer

If IsNull(Hour) Then
  HoursMinutes = Null
Else
  Hrs = Int(Hour * 24)
  Mins = CInt((Hour * 24 - Hrs) * 60)
  If Mins = 60 Then
    Mins = 0
    Hrs = Hrs + 1
  End If
  HoursMinutes = Hrs & ":" & Format(Mins, "00")
End If

End Function

Store the function in a module, which you can use, for example, to calculate the total of a worker's daily hours in query.

List all the queries in your database

The following function prints to the immdiate window all the queries in your database, including SQL strings defined as form recordsources and as control rowsources.

Function QueriesList() As Boolean
On Error GoTo QueriesListErrorHandler

Dim db As Database
Dim qdf As QueryDef

Set db = CurrentDb

For Each qdf In db.QueryDefs

Debug.Print ""
Debug.Print "Name: " & qdf.Name
Debug.Print "Description: " & qdf.Properties("Description")
Debug.Print "Date Created: " & qdf.DateCreated
Debug.Print "Date Modified: " & qdf.LastUpdated
Debug.Print "SQL: "
Debug.Print qdf.SQL
Debug.Print "___________________________________________________________________________"
Next qdf

QueriesList = True

Exit Function
QueriesListErrorHandler:

If Err = 3270 Then 'Description property not found ie. there is no description for this query

Debug.Print "Description: na"
Resume Next

Else

QueriesList = False
MsgBox "Query Definition Error " & Err & ". " & Err.Description, , aad_THIS_APP
Exit Function

End If

End Function

Replace String Function for Access 97

A neat function from Skrol29 that you can use in Access97, which does not have the native Replace function available in Access2000. Visit Skrol29's web site at http://www.rezo.net/skrol29 to download his great V97/V2000 Access add-in.

Public Function ReplaceString(Str As String, WhatStr As String, WithStr As String) As String
'skrol29@freesurf.fr

Dim s As String
Dim i As Integer

s = Str
i = 1

If Len(WhatStr) > 0 Then
Do Until i > Len(s)
If Mid$(s, i, Len(WhatStr)) = WhatStr Then
s = Left$(s, i - 1) & WithStr & Mid$(s, i + Len(WhatStr))
i = i + Len(WithStr)
Else
i = i + 1
End If
Loop
End If

aad_ReplaceString = s

End Function

Query MSysObjects

The Access system table, MSysObjects, contains detailed information about the objects in an Access database. To view the table, in the Database Window, select Tools, Options from the Menubar, and in the View tab of the Options dialog, tick "System Tables" in the Show section. All system tables will now be listed in the Tables tab of the Database Window.

There are five key fields in the MSysObjects table:

• Name the name of the object
• DateCreate the date and time the object was created
• DateUpdate the last date and time the object was changed
• Connect And Database information on connections and linked tables
• Type an integer identifying the object type:

  Table 1
  Query 5
  Form -32768
  Report -32764
  Data Access Page -32756 'Access2000/2002 only
  Macro -32766
  Module -32761
  Relationship 8
  
  You can easily document basic information on your database by querying the MSysObjects table. For example, the SQL query:

  SELECT MsysObjects.Name, MsysObjects.DateCreate
  FROM MsysObjects
  WHERE ((Left([Name],4)<>"MSys") AND ((MsysObjects.Type)=1))
  ORDER BY MsysObjects.Name;

  will list each user table and its creation date in your database.

Access 2002 / Office XP Clipboard

In an Office XP application, start the Office Clipboard by selecting Edit, Office Clipboard... from the Menubar (or by holding down the Ctrl key and pressing the C key twice). The Office Clipboard will appear as a pane in the application window and a clipboard icon is placed in the Windows Taskbar icon tray. The Clipboard holds up to 24 items in a thumbnail gallery, including anything you copy or cut from any application, not just Office. Each time an item is added to the clipboard a tool tips type box hovers above the clipboard icon in the icon tray confirming the clipboard action.

You can't drag and drop graphics from the Office Clipboard into a document, but you can click inside the document where you want to paste, then click on the thumbnail in the Clipboard to paste into the document.

Calculate the Number of Days Remaining in Current Year

Function DaysToEndOfYear(dtDate As Date) As Long
'Calculate the number of days remaining in the current year
'from a given date in the current year - dtDate

DaysToEndOfYear = DateDiff("d", dtDate, DateSerial(Year(dtDate), 12, 31))

End Function

Email an Access Report

The following function uses the SendObject method of the the DoCmd object. Search for SendObject in Access Help for details.

Function fnEmailReport

Dim stTo As String
Dim stSub As String ' Subject
Dim stMsg As String ' Body of Message
Dim stRpt As String ' Name of Report

stReportName = "rptExample"
stTo = "jblow@zzz.net.au"
stSub = "Example Report Attached"
stMT = "The attached file is the latest Example Report."

DoCmd.SendObject acSendReport, stRpt, acFormatRTF, stTo, , , stSub, stMsg, True

End Function

MSDN Connection
Professional Developer