Passing VBA variable to Access Query Criteria - sql

I have a simple task giving me a lot of trouble.
What I need is to simply move a variable from my VBA macro to a function, to be able to use it in an Access Query.
ADDED: I have created a small and simple access document with a simple VBA. Download it at:
http://sharesend.com/olpy1o7d
If someone could be kind to download and see what I am doing wrong, I would really prefer it.
In the form f_main I need to be able to change counter to whatever number and hence get an updated query when the button is pressed in the main form.
It is described below, but downloading it may explain my situation easier.
EDITED:
Public counter as Integer
Private Sub Command_Click()
counter = 1
End Sub
And in a module:
Public Function n()
n = counter
End Function
In access, I have a SQL Query as:
SELECT t_Data.ID, n() AS Expr1 FROM t_Data;
Access says it can not find the function n()
If i use the function builder, i can see n(), so i guess it is because the function n() is empty - It can not find "counter" declared in my form.
What can i do?

To help future bummers like mine, I found the error.
I named the module the same as the function, which caused the problem.
By changing the name of the module from n to m_n, and keeping the function name n() it worked perfectly fine.
Stupid mistake is stupid. But thank you guys who looked into my issue.

Declaring a variable as public in a form seems to not actually make it globally public. This has annoyed me many times in Access. Move your declaration of counter to your Module code and you should see a change in operation.
There is a good discussion of this behavior in the following SO post (Public variables are not REALLY public in VBA in Forms).

Related

Variable in a form won't keep its value after being used in the call to another form

I have a form with a variable in it called "VigilTable." This variable gets its value from the calling string OpenArgs property.
Among other things, I use this variable in the call string when opening other forms.
But it only works the first call.
MsgBox VigilTable before the call will always show "Spring2022" or whatever on the first call but always comes up blank on succeeding calls (and I get "invalid use of NULL" when the called form attempts to extract the value from OpenArgs). The variable is dimmed as String in the General section of the form's VBA code.
So what's happening here? And can I fix it?
Thanks.
Ok, so you delcared a variable at the form level (code module) for that given form.
and we assume that say on form load, you set this varible to the OpenArgs of the form on form load.
So, say like this:
Option Compare Database
Option Explicit
Public MyTest As String
Private Sub Form_Load()
MyTest = Me.OpenArgs
End Sub
Well, I can't say having a variable helps all that much, since any and all code in that form can use me.OpenArgs.
but, do keep in mind the following:
ONLY VBA code in the form can freely use that variable. It is NOT global to the applcation, but only code in the given form.
However, other VBA code outside of the form can in fact use this variable. But ONLY as long as the form is open.
So, in the forms code, you can go;
MsgBox MyTest
But, for VBA outside of the form, then you can get use of the value like this:
Msgbox forms!cityTest.MyTest
However, do keep in mind that any un-handled error will (and does) blow out all global and local variables. So, maybe you have a un-handled error.
Of course if you compile (and deploy) a compiled accDB->accDE, then any errors does NOT re-set these local and global variables.
but, for the most part, that "value" should persist ONLY as long as the form is open, and if you close that form, then of course the values and variables for that form will go out of scope (not exist).
Now, you could consider moving the variable declare to a standard code module, and then it would be really global in nature, but for the most part, such code is not recommended, since it hard to debug, and such code is not very modular, or even easy to maintain over time.
So, this suggests that some error in VBA code is occurring, and when that does occur, then all such variables are re-set (but, the noted exception is if you compile down to an accDE - and any and all variables will thus persist - and even persist their values when VBA errors are encountered.
For a string variable, a more robust solution not influenced by any error, should be writing/reading in/from Registry. You can use the, let as say, variable (the string from Registry) from any workbook/application able to read Registry.
Declare some Public constants on top of a standard module (in the declarations area):
Public Const MyApp As String = "ExcelVar"
Public Const Sett As String = "Settings"
Public Const VigilTable As String = "VT"
Then, save the variable value from any module/form:
SaveSetting MyApp, Sett, VigilTable , "Spring2022" 'Save the string in Regisgtry
It can be read in the next way:
Dim myVal as String
myVal = GetSetting(MyApp, Sett, VigilTable , "No value") 'read the Registry
If myVal = "No value" Then MsgBox "Nothing recorded in Registry, yet": Exit Sub
Debug.print myVal
Actually, this proved not to be the the answer at all.
It was suggested that I declare my variables as constants in the Standard module but I declared them as variables. It appeared at first to work, at least through one entire session, then it ceased to work and I don't know why.
If I declare as constants instead, will I still be able to change them at-will? That matters because I re-use them with different values at different times.
I didn't do constants but declaring VigilName in the Standard module and deleting all other declarations of it fixed both problems.
While I was at it I declared several other variables that are as generally used and deleted all other declarations of them as well so that at least they'll be consistently used throughout (probably save me some troubleshooting later.
Thanks to all!

How to make my module move an object using value set in UserForm/

I'm trying to automatize some processes I often do at work. Unfortunately I have no clue about programming so I've been struggling a lot with this.
I have an userform that has a textbox where you're supposed to type in how much you want the object to be moved on X axis. There are multiple objects and I can't wait to experiment how to move them all in proper direction, but the issue is, I can't even move one.
I created a variable, but I can't seem to be able to use it with Object.Move.
Right now VBA tells me to assign the values to an array, so I did that, but I can't put variables into an array apparently.
I've tried simply declaring the variable as public, calling it let's say for example "Value", and using Object.Move (Value), 0
or
Object.Move Value(), 0
Tried both, because I was not sure which one is correct.
After many trials I finally skipped most of the previous errors I was getting, and now I'm stuck at trying to set up an Array using a variable from the UserForm.
Here's the code inside Userform
VBA
Public Sub TextBox1_Initialize()
M = TextBox1
Unload M
End Sub
And here's the code inside the module
VBA
Public M As Integer
Sub Move()
Dim XY(M, 0) As Integer
Object.Move XY
End Sub

How do I effectively create controls dynamically in Excel's VBA or How do I use Application.OnTime()?

I am working on a very large VBA project in Excel at my job. We are about 1500 lines of code for just one feature and have about a dozen more features to add. Because of this, I've been trying to break everything down so that I can keep code for each feature in separate places. OOP sucks in VBA... The problem being that these controls MUST have events fired. Of course, some events (like the TextBox_AfterUpdate event) are not available when you dynamically create controls. It's a bit convoluted because of everything that is going on, so I'll break it down the best I can:
I have a class module that represents a tab for a multipage control. When a user clicks on a tab, the Userform calls this class module and THERE I have the controls created dynamically. This way I can keep the code in that class module. I have a sub that I deemed as the "AfterUpdate" sub and put code that I needed to run there. Now the problem is to get that sub to be called at the appropriate time.
So what I did is to set up a Timer of sorts to check and see if the "ActiveControl" is said textbox. If it is not, we can assume that focus has left and we can raise that event. Here's the code I'm using:
An abbreviated version of the tab creation...
Private WithEvents cmbMarketplace As MSForms.ComboBox
Public Sub LoadTab(ByVal oPageTab As Object)
If TabLoaded Then Exit Sub
Set PageTab = oPageTab
Dim tmp As Object
Set tmp = PageTab.Add("Forms.Label.1")
tmp.Top = 6: tmp.Left = 6: tmp.Width = 48
tmp.Caption = "Marketplace:"
Set cmbMarketplace = PageTab.Add("Forms.ComboBox.1", "cmbMarketplace")
' LOAD OTHER CONTROLS '
TabLoaded = True
Start_Timer
End Sub
Then Start_Timer:
Public Sub Start_Timer()
TimerActive = True
Application.OnTime Now() + TimeValue("00:00:01"), "Timer"
End Sub
And the sub that is to be fired:
Public Sub Timer()
If TimerActive Then
' DO SOME RANDOM THINGS '
Application.OnTime Now() + TimeValue("00:00:01"), "Timer"
End If
End Sub
Does this seem like a reasonable approach to solving the problem I'm facing? I'm open to suggestions...
That's the first problem. This seems like a lot of work to accomplish this. (I'm working on getting visual studio, but I don't know if that's going to happen)
The above code will work but the "Timer" sub will not get raised at all. I get no errors if I just run the code. Everything is created, everything works as I would hope. However, if I step through the code, I eventually will get the following error:
Cannot run the macro "...xlsm!Timer". The macro may not be available in this workbook or all macros may be disabled.
Obviously neither of those suggestions are valid. Macros ARE enabled and the sub is in the same darn class module. I tried making it public, same problem. Tried "ClassModule1!Timer" to no avail. I'm at my wits end trying to figure this out. Thinking of having people write ALL this in the Userform or just giving up.
Does anybody have any suggestions on how to effectively break up large chunks of code? And does anybody have a clue why this sub will not run and seemingly cannot be found?
I understand that this is a confusing situation, so if you need more info or code examples or want to know why I have something set up the way I do, let me know.
Thanks!
Obviously neither of those suggestions are valid. Macros ARE enabled and the sub is in the same darn class module.
There's the problem: a macro cannot be in a class module. The message is entirely correct: VBA cannot see the Timer procedure, because it's not accessible.
A class module is a blueprint for an object, VBA (or any OOP language for that matter) can't do anything with a class module, without an instance of that class - i.e. an object.
Your timer callback needs to be a Public Sub in a standard module, so that it can be called directly as a macro. Public procedures of a class modules are methods, not macros.
Depending on what ' DO SOME RANDOM THINGS ' actually stands for, this may or may not require some restructuring.
1500-liner spaghetti code can be written in any language BTW.

Public variables are not REALLY public in VBA in Forms

Below is a question that I will answer myself, however it caused a GREAT deal of frustration for me and I had a lot of trouble searching for it on the web, so I am posting here in hopes of saving some time & effort for others, and maybe for myself if I forget this in the future:
For VBA (in my case, MS Excel), the Public declaration is supposed to make the variable (or function) globally accessible by other functions or subroutines in that module, as well as in any other module.
Turns out this is not true, in the case of Forms, and I suspect also in Sheets, but I haven't verified the latter.
In short, the following will NOT create a public, accessible variable when created in a Form, and will therefore crash, saying that the bYesNo and dRate variables are undefined in mModule1:
(inside fMyForm)
Public bYesNo As Boolean`
Public dRate As Double
Private Sub SetVals()
bYesNo = Me.cbShouldIHaveADrink.value
dRate = CDec(Me.tbHowManyPerHour.value)
End Sub
(Presume the textbox & checkbox are defined in the form)
(inside mModule1)
Private Sub PrintVals()
Debug.Print CStr(bYesNo)
Debug.Print CStr(dRate)
End Sub
However, if you make the slight alteration below, it all will work fine:
(inside fMyForm)
Private Sub SetVals()
bYesNo = Me.cbShouldIHaveADrink.value
dRate = CDec(Me.tbHowManyPerHour.value)
End Sub
(Presume the textbox & checkbox are defined in the form)
(inside mModule1)
Public bYesNo As Boolean`
Public dRate As Double
Private Sub PrintVals()
Debug.Print CStr(bYesNo)
Debug.Print CStr(dRate)
End Sub
mModule1 will work perfectly fine and, assuming that the fMyForm is always called first, then by the time the PrintVals routine is run, the values from the textbox and checkbox in the form will properly be captured.
I honestly cannot possibly fathom what MS was thinking with this change, but the lack of consistency is a huge suck on efficiency, learning idiosyncracies like these, which are so poorly documented that a Google search in 2013 for something that has likely been around for a decade or more is so challenging to search.
First comment:
Userform and Sheet modules are Object modules: they don't behave the same way as a regular module. You can however refer to a variable in a userform in a similar way to how you'd refer to a class property. In your example referring to fMyForm.bYesNo would work fine. If you'd not declared bYesNo as Public it wouldn't be visible to code outside of the form, so when you make it Public it really is different from non-Public. – Tim Williams Apr 11 '13 at 21:39
is actually a correct answer...
As a quick add-on answer to the community answer, just for a heads-up:
When you instantiate your forms, you can use the form object itself, or you can create a new instance of the form object by using New and putting it in a variable. The latter method is cleaner IMO, since this makes the usage less singleton-ish.
However, when in your userform you Call Unload(Me), all public members will be wiped clean. So, if your code goes like this:
Dim oForm as frmWhatever
Set oForm = New frmWhatever
Call oForm.Show(vbModal)
If Not oForm.bCancelled Then ' <- poof - bCancelled is wiped clean at this point
The solution I use to prevent this, and it is a nice alternative solution for the OP as well, is to capture all IO with the form (i.e. all public members) into a separate class, and use an instance of that class to communicate with the form. So, e.g.
Dim oFormResult As CWhateverResult
Set oFormResult = New CWhateverResult
Dim oForm as frmWhatever
Set oForm = New frmWhatever
Call oForm.Initialize(oFormResult)
Call oForm.Show(vbModal)
If Not oFormResult.bCancelled Then ' <- safe
There are other limitations to Public within Excel VBA.
MSoft documentation in learn.microsoft.com states that public variables are global to the VBA project - it's not true.
Public variables are only global to the workbook within which they are declared, and then only across standard modules. Public variables declared within workbook code are not visible in standard modules, even though standard module sub's are - which are defined to be public.
Public variables declared in one workbook's standard modules are certainly not accessible from other workbooks in the same VBA project, contrary to the MSoft documentation.

Profiling VBA code for microsoft word

I have some legacy code that uses VBA to parse a word document and build some XML output;
Needless to say it runs like a dog but I was interested in profiling it to see where it's breaking down and maybe if there are some options to make it faster.
I don't want to try anything until I can start measuring my results so profiling is a must - I've done a little searching around but can't find anything that would do this job easily. There was one tool by brentwood? that requires modifying your code but it didn't work and I ran outa time.
Anyone know anything simple that works?
Update: The code base is about 20 or so files, each with at least 100 methods - manually adding in start/end calls for each method just isn't appropriate - especially removing them all afterwards - I was actually thinking about doing some form of REGEX to solve this issue and another to remove them all after but its just a little too intrusive but may be the only solution. I've found some nice timing code on here earlier so the timing part of it isn't an issue.
Using a class and #if would make that "adding code to each method" a little easier...
Profiler Class Module::
#If PROFILE = 1 Then
Private m_locationName As String
Private Sub Class_Initialize()
m_locationName = "unknown"
End Sub
Public Sub Start(locationName As String)
m_locationName = locationName
MsgBox m_locationName
End Sub
Private Sub Class_Terminate()
MsgBox m_locationName & " end"
End Sub
#Else
Public Sub Start(locationName As String)
'no op
End Sub
#End If
some other code module:
' helper "factory" since VBA classes don't have ctor params (or do they?)
Private Function start_profile(location As String) As Profiler
Set start_profile = New Profiler
start_profile.Start location
End Function
Private Sub test()
Set p = start_profile("test")
MsgBox "do work"
subroutine
End Sub
Private Sub subroutine()
Set p = start_profile("subroutine")
End Sub
In Project Properties set Conditional Compilation Arguments to:
PROFILE = 1
Remove the line for normal, non-profiled versions.
Adding the lines is a pain, I don't know of any way to automatically get the current method name which would make adding the profiling line to each function easy. You could use the VBE object model to inject the code for you - but I wonder is doing this manually would be ultimately faster.
It may be possible to use a template to add a line to each procedure:
http://msdn.microsoft.com/en-us/library/aa191135(office.10).aspx
Error handler templates usually include an ExitHere label of some description.. The first line after the label could be the timer print.
It is also possible to modify code through code: "Example: Add some lines required for DAO" is an Access example, but something similar could be done with Word.
This would, hopefully, narrow down the area to search for problems. The line could then be commented out, or you could revert to back-ups.
Insert a bunch of
Debug.Print "before/after foo", Now
before and after snippets that you think might run for long terms, then just compare them and voila there you are.
My suggestion would be to divide and conquer, by inserting some timing lines in a few key places to try to isolate the problem, and then drill down on that area.
If the problem is more diffused and not obvious, I'd suggest simplifying by progressively disabling whole chunks of code one at a time, as far as is possible without breaking the process. This is the analogy of finding speed bumps in an Excel workbook by progressively hard coding sheets or parts of sheets until the speed problem disappears.
About that "Now" function (above, svinto) ...
I've used the "Timer" function (in Excel VBA), which returns a Single.
It seems to work just fine. Larry