Using BatchCollisions on Form's recordset? - ms-access

Hoping to get more information on what column, table or row is causing a write conflict in a MS Access 2010 project, I wrote the following code:
Private Sub Form_BeforeInsert(Cancel As Integer)
Call printCollisionInfo(Me.Recordset, Me.name)
End Sub
Private Sub Form_BeforeUpdate(Cancel As Integer)
Call printCollisionInfo(Me.Recordset, Me.name)
End Sub
Method printCollisionInfo is:
Public Sub printCollisionInfo(rst As Recordset, formName As String)
Dim msg As String
msg = Now & " From " & formName & ": " & rst.BatchCollisionCount & " collisions"
Debug.Print msg
End Sub
But when calling rst.BatchCollisionCount, I get
"Operation is not supported for this type of object"
Is it because a form does not perform a dbUpdateBatch but some other type of update? Can I set the form's update type? Is there another way to see the SQL (with data values) or data that triggered the conflict?

The Recordset.BatchCollisionCount property is only valid for ODBCDirect workspaces.
This is stated in the Access 2010 online help, but unfortunately not on the MSDN page:
https://msdn.microsoft.com/en-us/library/office/ff198240(v=office.14).aspx
Look at how the recordset is set up in the example on that page. This is about as far from a bound form's recordset as it can be.
Here is an intro about ODBCDirect: http://www.avdf.com/may97/art_optimist.html
This technique is old, but the fact, that your question is #11 on my google search, gives you a hint about how many people use it...
I suggest a new question where you describe your setup and the error(s) you get.

Related

MS Access Library Template - Reference Category Value in VBA

Completely new to MS Access - I'm trying to do a simple modification to the MS Access Lending Library template using VBA.
Going into the Asset List form and clicking New Asset pops up the Asset Details form, where I can click the Save and New button. This calls the VBA code cmdSaveandNew_Click().
My question is, within this VBA method, how do I reference the values of the fields in the Asset Details form - For example getting the value that the user entered in the Category field and storing it in a variable.
I've tried several strings of code to try to get the value back, but I keep getting various errors, saying it can't find the referenced form, or Object Required, or this method is supported. I think it's likely just that I don't fully understand the structure of what I'm trying to reference or the syntax for specifying how to reference it.
Right now (after I've been trying many different combinations of things, I have:
text = Forms![Asset List].[Asset Details].Form.Category
which is giving me the "can't find the field '|1' referred to in your expression" error.
Edit - code currently looks like this:
Private Sub cmdSaveandNew_Click()
'On Error GoTo cmdSaveandNew_Click_Err
Dim someVar As String
Dim num As Integer
Dim objtf
'objtf = Forms![Asset List].[Asset Details].Form.Category
objtf = Me.Category
'num = Form.Controls.Count
Msg.Box (TypeName(objtf))
someVar = InputBox("How many?")
On Error Resume Next
If (Form.Dirty) Then
DoCmd.RunCommand acCmdSaveRecord
End If
If (MacroError.Number <> 0) Then
Beep
MsgBox MacroError.Description, vbOKOnly, ""
Exit Sub
End If
On Error GoTo 0
DoCmd.GoToRecord , "", acNewRec
DoCmd.GoToControl "Item"
MsgBox someVar
cmdSaveandNew_Click_Exit:
Exit Sub
cmdSaveandNew_Click_Err:
MsgBox Error$
Resume cmdSaveandNew_Click_Exit
End Sub
The variable must be declared global in a general module if you want to reference from various modules. Then setting it by code behind the Asset Details form would be simply: SomeVariableName = Me.Category.
Don't use reserved words as names - text is a reserved word.

Access Run-time Error 2475 *occasionally* occuring

I have an error log that logs in the access table whenever a runtime error occurs for a user in the error trapper, and a particular error seems to occur for 10 random users, every hour at least.
This error appears to occur completely at random, on a random module with the Set ActiveForm code, with random users at random intervals. As far as I can see, there is no pattern between the users.
2475 - "You entered an expression that requires a form to be the active window".
This appears to occur in any of the modules that contain any of the setting of a form. I am using the following lines:
Dim af as Object
Set af = Screen.ActiveForm
I have tried using alternatives, such as declaring it as Form, and also tried the below:
Dim sstatus as String
Dim ps as String
If DLookup("[TM_UserType]", "[SD_Teams]", "[TM_username]= '" & usernm & "'") = "adj" Then
sstatus = "adj"
Else
sstatus = "tm"
End If
ps = "frmProdSubmit_" & sstatus
Then referencing the form this way:
Forms(ps).cmbTeam.Value = ""
But this still causes the same issue, even removing the ActiveForm part.
The last thing to mention (as I believe they could be factors) is that the front end is accessed through a shortcut, which minimises the Access window. Not sure if this could be the culprit, or if the user clicking another application can remove the focus.
The back-end of the database is also accessed by up to around 700 users each day.
As it stands, the error trapper pops up with the message, but the front end continues working correctly. It's just an annoying issue to resolve, but am slowly running out of ideas now, and any help would be hugely appreciated!
Error 2475 is thrown when a non-form object is the active screen object such as a table datasheet. I've encountered this error in an application that uses multiple instances of a form and needs to track whether the multiple form module is active or one of the other application module functions in which case all instances of the multiple forms (popups) need to have .visible set to false. I use the Screen.ActiveForm.Name call in the Form_Deactivate event.
You can trap the error in the procedure's error handler and take action knowing the screen's active object is not a form.
Example:
Private Sub Form_Deactivate()
On Error GoTo errHandler
If Screen.ActiveForm.Name <> "AnApplicationForm" Then 'throws 2475 if not a form object
sstatus = "status message"
End If
ExitSub:
Exit Sub
errHandler:
If Err.Number = 2475 Then Resume Next 'screen active object is not a form i.e. datasheet
MsgBox "Error in " & Me.Name & ".Form_Deactivate: " & Err.Number & " - " & Err.Description
Resume ExitSub
End Sub 'Form_Deactivate

Show Users on Access Database

I am trying to show all the users that is currently on my Access database. I am using a VBA code that I found online and am trying to modify it to my needs. I am trying to get all the available users and display it on List Box on my form called "ListUsers".
The code is able to output to the debug window but I'm unable to update my list box. I get the following error: "Run-time error '6014': The RowSourceType property must be set to 'Value List' to use this method." I looked on the property window for that list box and couldn't find anything related to RowSourceType. I have tried a few different suggestions online but I am still unable to update the list box, so I wanted to see if anyone here may have some ideas. My code is below, I placed the VBA code on a button click.
Option Compare Database
Option Explicit
Private Sub cmd_Users_Click()
Dim cn As New ADODB.Connection
Dim rs As New ADODB.recordset
Dim i, j As Long
Set cn = CurrentProject.Connection
' The user roster is exposed as a provider-specific schema rowset
' in the Jet 4.0 OLE DB provider. You have to use a GUID to
' reference the schema, as provider-specific schemas are not
' listed in ADO's type library for schema rowsets
Set rs = cn.OpenSchema(adSchemaProviderSpecific, _
, "{947bb102-5d43-11d1-bdbf-00c04fb92675}")
'Output the list of all users in the current database.
Debug.Print rs.Fields(0).Name, "", rs.Fields(1).Name, _
"", rs.Fields(2).Name, rs.Fields(3).Name
While Not rs.EOF
Debug.Print rs.Fields(0), rs.Fields(1), _
rs.Fields(2), rs.Fields(3)
ListUsers.AddItem "'" & rs.Fields(0) & "-" & rs.Fields(1) & "'"
rs.MoveNext
Wend
End Sub
I figured it out... I had to set the RowSourceType on the code. I added the following to the button click event:
Me.ListUsers.RowSourceType = "Value List"
There is also a good post here:
Ms Access AddItem with VBA

How to update a subform after performing a DELETE query?

I have a form, myForm, that includes a subform, mySubform. The records in mySubform have a many to one relationship with the record source of the myForm, as expected, and There is a combobox in mySubform, myCombo, whose values is linked to one of the columns of the record source of mySubform.
I have been having difficulty to delete a record in mySubform, by erasing the current value in myCombo. I have put the code below under the OnChange event of myCombo (after trying many different alternatives).
Please not that I have simplified the delete query and the actual one works fine in the back-end (SQL Server). However, after performing the delete operation, I get this error when the execution reaches Me.Requery:
Error 3162 You tried to assign a Null value to a variable that is not a Variant data type.
Also, after having the degugger skip the Me.Requery and going back to the form, the deleted record shows "#DELETED" in every combobox and textbox for that particular record, and mySubform is not any good beyond that point.
I have looked up very many resources and tried different statements instead of Me.Requery, but none has worked so far. Help is much appreciated.
Private Sub myCombo_Change()
If IsNull(Me.myCombo.Text) Or Me.myCombo.Text = vbNullString Then
Dim strSql As String
strSql = "DELETE FROM mySubformRecordSource WHERE PrimaryKeyColumn= " & theCurrentPrimaryKeyValueForTheValueIn_MyCombo
CurrentDb.Execute strSql
Me.Requery
End If
End Sub
I solved the problem by putting Me.Dirty = False after reading this discussion:
Editing Record issues in Access / SQL (Write Conflict)
Private Sub myCombo_Change()
If IsNull(Me.myCombo.Text) Or Me.myCombo.Text = vbNullString Then
Me.Dirty = False
Dim strSql As String
strSql = "DELETE FROM mySubformRecordSource WHERE PrimaryKeyColumn= " & theCurrentPrimaryKeyValueForTheValueIn_MyCombo
CurrentDb.Execute strSql
Me.Requery
End If
End Sub
The form and subform work flawlessly now, but I still dont quite understand the complete logic behind the solution. It has something to do with Me.Dirty=False saving the changes to the content of a non-nullable (or nullable, both work fine) column before programmatically delete the entire record. How exactly though, I dont know and will appreciate input.
Not entering on the choices of used cursors etc I think that the solution could be simply "requery" the parent form called by the code of the subform.
But i also have found similar situation in past projects that i made (sorry not beeing exaustive, i'm not using VBA anymore) and the requery command was done on subform but from the main form code, something like this:
If local_procedures.deleteContratto(anagrafica_id_par, servizio_id_par) = OK Then
Me.subfrm_contratti_frm_anagrafica.Requery
...
In this case you could delegate parent form to call delete procedure and update logic (.Requery) of the child form, by mean of an event raised from subForm listen on parent for example.
For the sake of completeness i started hinting about cursors because i think it's the underlying reason for these kind of sync failures between recordsets, the parent form one and the child form one.
There are many advices about using dbSeeChanges with db.Execute on SQL Server backend and the resulting default cursors.
UPDATE
Here's a code snippet where a custom event is raised from child to be caught from parent that is delegated to execute code regarding the child.
This pattern doesn't break the parent-child/one-to-many logic, assuming parent has more decision power than child.
' in mySubform
' assuming theCurrentPrimaryKeyValueForTheValueIn_MyCombo is a Long ID
Public Event DeleteRequest(record_ID As Long)
Private Sub myCombo_Change()
If IsNull(Me.myCombo.Text) Or Me.myCombo.Text = vbNullString Then
RaiseEvent DeleteRequest(theCurrentPrimaryKeyValueForTheValueIn_MyCombo)
End If
End Sub
' in myForm
Private WithEvents frmMySubform As Form__mySubform
' you could have more instances of mySubform concerning different issues or subrecords and manage each one correctly ...
Private WithEvents frmMySubform2nd As Form__mySubform
Private Sub frmMySubform_DeleteRequest(record_ID As Long)
Dim strSql As String
strSql = "DELETE FROM mySubformRecordSource WHERE PrimaryKeyColumn= " & record_ID
CurrentDb.Execute strSql
With Me.frmMySubform.Form
.Requery
' ...
end With
End Sub
Private Sub frmMySubform2nd_DeleteRequest(record_ID As Long)
Dim strSql As String
strSql = "DELETE FROM my2ndSubformRecordSource WHERE PrimaryKeyColumn= " & record_ID
CurrentDb.Execute strSql
With Me.frmMySubform2nd.Form
.Requery
' ...
end With
End Sub

MS Access - check sub-form before entry for duplicate

I've got a subform (customersAnswersSub) inside of a main form (customersAnswers). Upon someone entering a new customerAnswersSub entry - I wanted it to check for duplicates first.
It has to check across 4 different fields to match first.
This is what I've got so far.
Private Sub Form_BeforeUpdate(Cancel As Integer)
Dim rsGlobals As ADODB.Recordset
Dim sql
Set rsGlobals = New ADODB.Recordset
sql = "Select * From CustomerAnswerD where subscriptionNo=" & _
Me.subscriptionNo & " AND journal=" & Me.Journal & _
" AND volume=" & Me.volume & " AND issue=" & Me.issue
rsGlobals.Open sql, CurrentProject.Connection, adOpenDynamic, adLockOptimistic, adCmdText
If Not rsGlobals.BOF And Not rsGlobals.EOF Then
MsgBox ("Already entered")
Cancel = True
Me.Undo
End If
End Sub
it doesn't do anything - just sits there. when I close the form it'll pop up a - id already exists box.
Any idea, i'm pretty unexperienced when it comes to Access VB.
thank you
it doesn't do anything - just sits there
Just checking, since you said you're inexperienced with Access ... the form update event is not triggered until the record save is attempted. That may not happen automatically as soon as the user enters data into all the fields. However, you can trigger the update by navigating to a different record in the subform, or by a method such as choosing Records->Save Record from Access' (2003) main menu.
I don't see anything wrong with your BeforeUpdate procedure. Still I would convert it use the DCount() function instead of opening an ADO recordset. (See Access' help topic for DCount)
Private Sub Form_BeforeUpdate(Cancel As Integer)
Dim strCriteria As String
strCriteria = "subscriptionNo=" & Me.subscriptionNo & " AND journal=" & Me.Journal & _
" AND volume=" & Me.volume & " AND issue=" & Me.issue
Debug.Print strCriteria
If Dcount("subscriptionNo", "CustomerAnswerD", strCriteria) > 0 Then
MsgBox ("Already entered")
Cancel = True
Me.Undo
End If
End Sub
That assumes your table's subscriptionNo, journal, volume, and issue fields are all numeric data types. If any of them are text type, you will need to enclose the values in quotes within strCriteria.
I added Debug.Print strCriteria so you can view the completed string expression in the Immediate Window. You can also troubleshoot that completed string by copying it and pasting it into SQL View of a new query as the WHERE clause.
Also, consider adding a unique index on subscriptionNo, journal, volume, and issue to your CustomerAnswerD table design. That way you can enforce uniqueness without relying solely on your form to do it. The index will also give you faster performance with the DCount function, or your original recordset SELECT statement.
If you keep your original recordset approach, close the recordset and set the object variable = Nothing before exiting the procedure.