MS Access: calculated field is slower than VBA code - ms-access

I have a subform (continous mode) in my main form which is used to add some articles with description, amount and price. In the footer of this sumform is a textfield which sums up all the entries of the subform by using =sum([amount] * [price]). That works so far.
Each time when I add a new entry in the subform, this textfield gets calculated. Now I also want to have this sum in a textfield of my main form (which actually also is not a problem). In "AfterUpdate"-event of my combofield in the continuous form I write the value of the sum-textfield to my textfield in the mainform. This initially also worked perfectly.
But now (I have no clue what changed), my textfield in the mainform doesn't get the new value, because the vba code runs faster than the calculated textfield in my subform-footer calculates its new value. It always writes the old value to the mainform. I discovered the problem using brakepoints in my code. So the old value gets written to the mainform before access is finished calculating the sum of all subform-entries.
Here's the code which I use to write the value from my subform textfield to my mainform textfield:
Private Sub txt_Article_AfterUpdate()
Me.Refresh
Me.Parent!txt_Amount = Int(Me.txt_SumOfAmountsInContinuousForm * 20 + 0.5) / 20
End Sub
I hope the description of my problem is somewhat understandable. It's a bit difficult to describe it :)
Is there a way to wait with my vba code until the sum-field has its new value calculated?
Thanks

Related

Average of calculated field in Access subform

I am working in Access 2007 with a subform that shows the Mass of a determined set of records linked to a master form.
The form is displayed in spreadsheet view and has two columns [Mass] and [Include]. Include is a True/False field to select whether the record is to be included in the final calculation.
In the footer of the subform, I want to add the average of the masses of the records where [Include] = True.
So far I have created a new field [MassIF] = IIf([Include]=True,[Mass],Null), this works correctly in the spreadsheet.
However, the =Avg([MassIF]) control in the footer gives an error, any idea why that would be and how to get around the issue?
Also, =Avg([Mass]) works fine until I add to the footer the =Avg([MassIF]) control, then I get #ERROR in both fields, which looks really odd to me.
Try calculation in textbox in footer:
=Avg(IIf([Include], [Mass], Null))

Filtering in subreport

I have encountered issues with using "filtering menus" in report during development of database aplication for my employer.
For my filtering options I created buttons with OnClick Event:
DoCmd.GoToControl "MyReportField"
DoCmd.RunCommand acCmdFilterMenu
These buttons are embedded in subreport. Initial thought was to create buttons, similar to the one in ribbon, with filtering options (in final stages of development I am planning to disable/hide Access ribbon for users). I created 5 buttons, 3 for fields with data type Text, 1 with data type Date and 1 with Boolean data type.
To quote a classic, the buttons "are misbehaving." When I test their function in form in form view, the "BooleanFilterBtn" on click already doesn't display Yes/No options (or something similar), but displays 2 numeric values (like -24441 or -29696). And filter is not working whatsoever.
Another problem arises when I try to have active more than one filter at a time. Date field filter and one of the Text field filters are working when combined with another filter option. But after using one of the two remaining Text field filters, when I click any other of the filtering buttons, the FilterMenu becomes blank.
Worth noting is that right-clicking on given field in report works without issues, but not the way I want.
Given these rather odd behaviours I think I am missing something. Is there a way how to make FilterMenus work the way as familiar from the ribbon? If not, is there any other option with similar design, options that I could try out?
Additional info:
Subreport is connected with form through "MyIDField." Both subreport and form have query data source, already saved.
All field names and data types are matching.
EDIT: Also I should have written that the FilterBtns doesn't work if I open the subreport separately, they work only when I open form (with subreport in it), eventhough the FilterBtns are using only controls from the report.
EDIT2: Code behind filter button filtering Boolean data type (boolean data are in Report in form of Yes/No check-fields, as mentioned in June7 comment bellow):
Private Sub btn_FiltrGarant_Click()
DoCmd.GoToControl "Garant"
DoCmd.RunCommand acCmdFilterMenu
End Sub
When I change this code to:
Private Sub btn_FiltrGarant_Click()
Me.Garant.SetFocus
DoCmd.RunCommand acCmdFilterMenu
End Sub
Brings no effect, only that the loading time of actual FilterMenu takes a bit longer.
Example for Text data type field:
Private Sub btn_FiltrRzh_Click()
DoCmd.GoToControl "ZkracenyNazev"
DoCmd.RunCommand acCmdFilterMenu
End Sub
Changing code in the same manner:
Private Sub btn_FiltrRzh_Click()
Me.ZkracenyNazev.SetFocus
DoCmd.RunCommand acCmdFilterMenu
End Sub
Brings no effect too.
May it be that the FilterMenu is not meant to/available to be used in reports? Or may it be disabled in default settings of Access?
Because also the situation, that if I open the Report separately (not in form as a subreport, but just as report by itself in report view), using any of the FilterBtns gives me RunTime error 2046, that the action GoToControl is not available. Changing to SetFocus eliminates the error, but the button doesn't bring up any FilterMenu at all. But these issues are valid only if I open report separately (which is not my interest), but might be helpfull as information.
Right now, I don't know where the problem could be. Anything I could think of was data type/naming mismatch, but that's not the case.
FINAL EDIT: After almost a month (there were holydays) of trying and searching for a way how to make this setup work I decided to switch from subreport to subform, in which I will try to obtain the same functionality.
Maybe just reports are not supposed to be handled the way I wanted to.
Just out of courtesy I am putting June7 answer as verifiedfor the time spent on helping me.
Thank you.
Don't know why your yes/no field displays 2 numeric values like -24441 or -29696 in the filter menu. Regardless, not able to get the filter menu to act on a yes/no field at all. However, get around that with an expression in report RecordSource query that changes the Yes/No field from Boolean to text values and use the calculated field in report design, like:
SELECT *, IIf([fieldname], "Yes", "No") AS IsSomethingTrue FROM tablename;
Use Me.controlname.SetFocus instead of GoToControl so the report will open independently or as a sub object.
You have to be careful how you refer to a Report object that is within a subForm container. They do not behave the same as subforms in many ways.
Even a simple refresh is actually difficult to achieve, as reports are not meant to be dynamic like a form.
To refer to it in VBA you have to use the full form syntax;
[Forms]![MainFormName].[Form]![subReportHolderName].Requery
Using the normal Me.blah.blah reference will not work with a form embedded report. Note that you refer to the container - NOT the report object.

tell MS Access VBA function to wait until subform finished calculation

I have a subform sfrmMySubForm including an unbound field called CountRows in the footer, which is set to =Count(*). The subform is displayed in table view. I dynamically change the filtering of sfrmMySubForm by VBA Code. This works fine.
After the filter has been updated, I like to change the height of the subform according to the number of rows shown now. I wrote a function to do that, using Me!sfrmMySubForm!CountRows to get the information. This works fine, if I trigger the function by button, but if I call it after the filter-update code, Me!sfrmMySubForm!CountRows returns 0 - apparently the function has been called, before the subform calculated the new value of CountRows (took me some hours to find out).
My Question:
How can I tell my function to wait until the subform finished it's calculations? Or is there another way to get the number of rows displayed in a subform after a filter update - another way, that doesn't lead into the same problem?
I already thought of just looping around until Me!sfrmMySubForm!CountRows > 0 but this won't work if there is really no data to be displayed...

access 2010 expression builder

I want a text box to contain data which is a calculation based on 2 other control field values - only if it's value is null (ie the current value of the column in the database is null).
So I entered =([control1]*[Control2])/1000 in the expression builder for the default value property - however the result always shows the textbox to be empty (even tho control2 and control2 contain values).
How can I achieve this? Can such an operation only be done in code-behind ie VB??
thanks,
KS
I think you're talking about a control bound to a field in the form's record source. And when the underlying field is Null, you want the control loaded with your calculated value.
If that interpretation is correct, you can do it from the form's On Current event.
If IsNull(Me.txtYourTextBox) Then
Me.txtYourTextBox = (Nz(Me.control1) * Nz(Me.Control2)) / 1000
End If
That will load the computed value into the text box, allow the user to change its value if desired, and store the value to the bound field when the record is saved.
If the bound field is not Null, its value will be displayed in the text box without alteration by the On Current code.
Is that what you want?
To accomplish this using VBA, add a Form_Load Event. (Open the form in Design View and in Form properties click the Event tab and choose Event Procedure for "On Load" and click ...)
This example uses [TextField] to refer to the table data.
Private Sub Form_Load()
TextControl.SetFocus
If IsNull([TextField]) Then
TextControl.Text = ([Control1] * [Control2]) / 1000
End If
End Sub

Custom row source for combo box in continuous form in Access

I have searched around, and it seems that this is a limitation in MS Access, so I'm wondering what creative solutions other have found to this puzzle.
If you have a continuous form and you want a field to be a combo box of options that are specific to that row, Access fails to deliver; the combo box row source is only queried once at the beginning of the form, and thus show the wrong options for the rest of the form.
The next step we all try, of course, is to use the onCurrent event to requery the combo box, which does in fact limit the options to the given row. However, at this point, Access goes nuts, and requeries all of the combo boxes, for every row, and the result is often that of disappearing and reappearing options in other rows, depending on whether they have chosen an option that is valid for the current record's row source.
The only solution I have found is to just list all options available, all the time. Any creative answers out there?
Edit Also, I should note that the reason for the combo box is to have a query as a lookup table, the real value needs to be hidden and stored, while the human readable version is displayed... multiple columns in the combo box row source. Thus, changing limit to list doesn't help, because id's that are not in the current row source query won't have a matching human readable part.
In this particular case, continuous forms make a lot of sense, so please don't tell me it's the wrong solution. I'm asking for any creative answers.
I also hate Access, but you must play with the cards you are dealt.
Continuous forms are a wonderful thing in Access, until you run into any sort of complexity as is commonly the case, like in this instance.
Here is what I would do when faced with this situation (and I have implemented similar workarounds before):
Place an UNBOUND combobox on the form. Then place a BOUND textBox for the field you want to edit.
Make sure the combobox is hidden behind (NOT invisible, just hidden) behind the textBox.
In the OnCurrent event fill the listBox with the necessary data. Go ahead and "Limit to list" it too.
In the OnEnter or OnClick event of the textBox give the combobox focus. This will bring the combobox to the forefront. When focus leaves the combobox it will hide itself once more.
In the AfterUpdate event of the combobox set the value of the textbox equal to the value of the combobox.
Depending on your situation there may be some other details to work out, but that should more or less accomplish your goal without adding too much complexity.
use continuous forms .. definitely. In fact you can build entire applications with great and intuitive user interface built on continuous forms. Don't listen to Toast!
Your solution of listing all options available is the correct one. In fact there is no other clean solution. But you are wrong when you say that Acccess goes nuts. On a continuous form, you could see each line as an instance of the detail section, where the combobox is a property common to all instances of the detail section. You can update this property for all instances, but cannot set it for one specific instance. This is why Access MUST display the same data in the combobox for all records!
If you need to accept only record-specific values in this combobox, please use the beforeUpdate event to add a control procedure. In case a new value cannot be accepted, you can cancel data update, bringing back the previous value in the field.
You cannot set the limitToList property to 'No' where the linked data (the one that is stored in the control) is hidden. This is logical: how can the machine accept the input of a new line of data when the linked field (not visible) stays empty?
You could also make the value of the combo box into an uneditable text field and then launch a pop-up/modal window to edit that value. However, if I was doing that, I might be inclined to edit the whole record in one of those windows.
I don't think that Access continuous forms should be condemned at all, but I definitely believe that they should be avoided for EDITING DATA. They work great for lists, and give you substantially more formatting capabilities than a mere listbox (and are much easier to work with, too, though they don't allow multi-select, of course).
If you want to use a continuous form for navigation to records for editing, use a subform displaying the detailed data for editing, and use the PK value from the subform for the link field. This can be done with a continuous form where you place a detail subform in the header or footer, linked on the PK of the table behind the continuous form.
Or, if you are using a continuous form to display child data in a parent form, you can link the detail subform with a reference to the PK in the continuous subform, something like:
[MySubForm].[Form]!MyID
That would be the link master property, and MyID would be the link child property.
We also encounter this a lot in our applicatins. What we have found to be a good solution:
Just show all rows in the comboboxes.
Then, as soon as the user enters the compobox in a specific row, adjust the rowsource (with the filter for that row). When the combobox loses the focus, you can re-set the rowsource to display everything.
I have a simpler way to go than Gilligan. It seems like a lot of work but it really isn't. My solution requires having my continuous form as a subform datasheet. On my subform I have two lookup comboboxes, among other fields, called Equipment and Manufacturer. Both simply hold a Long Integer key in the data source. Manufacturer needs to be filtered by what is selected in Equipment. The only time I filter Manufacturer.RowSource is in the Manufacturer_GotFocus event.
Private Sub Manufacturer_GotFocus()
If Nz(Me.Equipment, 0) > 0 Then
Me.Manufacturer.RowSource = GetMfrSQL() '- gets filtered query based on Equipment
Else
Me.Manufacturer.RowSource = "SELECT MfgrID, MfgrName FROM tblManufacturers ORDER BY MfgrName"
End If
End Sub
In Manufacturer_LostFocus I reset Manufacturer.RowSource to all Manufacturers as well. You need to do this because when you first click in the subform, GotFocus events fire for all controls, including Manufacturer, even though you are not actually updating any fields.
Private Sub Manufacturer_LostFocus()
Me.Manufacturer.RowSource = "SELECT MfgrID, MfgrName FROM tblManufacturers ORDER BY MfgrName"
End Sub
In the Enter event of Manufacturer you have to check if Equipment has been selected, if not set focus to Equipment.
Private Sub Manufacturer_Enter()
If Nz(Me.EquipmentID, 0) = 0 Then
'-- Must select Equipment first, before selecting Manufacturer
Me.Equipment.SetFocus
End If
End Sub
You also need to requery the Manufacturer combobox in Form_Current event (i.e. Me.Manufacturer.Requery), and you should set the Cycle property of this subform to "Current Record".
Seems simple enough, but you're not done yet. You also have to reset Manufacturer.RowSource to all Manufacturers in the SubForm_Exit event in the parent form in case the user goes to the Manufacturer combobox but does not make a selection and clicks somewhere on the parent form. Code sample (in parent form):
Private Sub sFrmEquip_Exit(Cancel As Integer)
Me.sFrmEquip.Controls("Manufacturer").RowSource = "SELECT MfgrID, MfgrName FROM tblManufacturers ORDER BY MfgrName"
End Sub
There is still one piece of this that is not clean. When you click on Manufacturer and have multiple rows in the datasheet grid, Manufacturer field will go blank in other rows (the data underneath the comboboxes is still intact) while you're changing the Manufacturer in the current row. Once you move off this field the text in the other Manufacturer fields will reappear.
This seems to work well.
CBOsfrmTouchpoint8 is a combobox shortened to just the dropdown square.
CBOsfrmTouchpoint14 is a textbox that makes up the rest of the space.
Never say never:
Private Sub CBOsfrmTouchpoint8_Enter()
If Me.CBOsfrmTouchpoint8.Tag = "Yes" Then
CBOsfrmTouchpoint14.SetFocus
Me.CBOsfrmTouchpoint8.Tag = "No"
Exit Sub
End If
Me.CBOsfrmTouchpoint8.Tag = "No"
Me.CBOsfrmTouchpoint8.RowSource = "XXX"
Me.CBOsfrmTouchpoint8.Requery
Me.CBOsfrmTouchpoint8.SetFocus
End Sub
Private Sub CBOsfrmTouchpoint8_GotFocus()
Me.CBOsfrmTouchpoint14.Width = 0
Me.CBOsfrmTouchpoint8.Width = 3420
Me.CBOsfrmTouchpoint8.Left = 8580
Me.CBOsfrmTouchpoint8.Dropdown
End Sub
Private Sub CBOsfrmTouchpoint8_LostFocus()
Me.CBOsfrmTouchpoint8.RowSource = "XXX"
Me.CBOsfrmTouchpoint8.Requery
End Sub
Private Sub CBOsfrmTouchpoint8_Exit(Cancel As Integer)
Me.CBOsfrmTouchpoint14.Width = 3180
Me.CBOsfrmTouchpoint8.Width = 240
Me.CBOsfrmTouchpoint8.Left = 11760
Me.CBOsfrmTouchpoint8.Tag = "Yes"
End Sub
What if you turn off the "Limit To List" option, and do some validation before update to confirm that what the user might have typed in matches something in the list that you presented them?
Better...
Set you combo box Control Source to a column on the query where the values from your combo box will be stored.
For Me I think the best way and easiest way is to create a temporary table that has all your bound fields plus an extra field that is a yeas/no field.
then you will use this table as the data source for the continuous for. You can use onLoad to fill the temporary table with the data you want.
I think it is easy after that to loop for the choices, just a small loop to read the yeas/no field form the temporary table.
I hope this will help
Use OnEnter event to populate the combo box, don't use a fixed rowsource.
I've just done similar. My solution was to use a fixed row source bound to a query. The query's WHERE clauses reference the form's control i.e. Client=Forms!frmMain!ClientTextBox. This alone will fill the combo boxes with the first row's data. The trick then is to set an 'On Enter' event which simply does a re-query on the combo box e.g. ComboBox1.Requery, this will re-query that combo box alone and will only drag in the data related to that record row.
Hope that works for you too!
Disclaimer: I hate Access with a passion.
Don't use continuous forms. They're a red herring for what you want to accomplish. Continuous forms is the same form repeated over and over with different data. It is already a kludge of Access's normal mode of operation as you can't have the same form opened multiple times. The behavior you are seeing is "as designed" in Access. Each of those ComboBox controls is actually the same control. You cannot affect one without affecting the others.
Basically, what you have done here is run into the area where Access is no longer suitable for your project (but cannot ditch because it represents a large amount of work already).
What seems to be the most likely course of action here is to fake it really well. Run a query against the data and then create the form elements programmatically based on the results. This is a fair amount of work as you will be duplicating a good bit of Access's data handling functionality yourself.
Reply to Edit:
But as they are, continuous forms cannot accomplish what you want. That's why I suggested faking out your own continuous forms, because continuous forms have real limitations in what they can do. Don't get so stuck on a particular implementation that you can't let go of it when it ceases to work.