I am doing a simple VBA script in Microsoft Excel which iterates a list of cars and a list of information about when the cars were refueled to provide an overview of how many kilometers each car is driving each month.
I make use of the Range.End property to calculate the number of rows with data and then loop through the indicies.
Set Data = Worksheets("Tankninger") ' Danish for refuellings
NumRows = Data.Range("A1", Data.Range("A1").End(xlDown)).Rows.Count
For x = 1 To NumRows
' Process data
Next
Everything seemed to be working fine, however I found that if someone applied a filter to e.g. the sheet with refuelling data - e.g. only showing data related to car A, then NumRows would be assigned the index of the last visible row.
Example: if the refuling sheet contains 100 records and the records related car A are located on row 50-60, then NumRows would be assigned the value 60 - resulting in my script ignoring the last 40 records.
Is there a way to make the Range.End property ignore any filter applied to sheet, or will I have to change the implementation to use a while-loop instead?
I ended up replacing the for-loop with a while-loop. This allowed me to access every cell regardless of any filtering applied to the sheets.
Set Data = Worksheets("Tankninger") ' Danish for refuellings
r = 2
While Not IsEmpty(Cars.Cells(r, 1).value)
' Process data
Wend
What you can do is add the following in your code to remove filters before you find the last row with data.
'Remove all filters
Worksheets("Sheet1").Activate
On Error Resume Next
ActiveSheet.ShowAllData
Greets,
I got this scenario with 3x different files;
1) one CSV file has Column A (-first row) with abbreviations that needs to be copied on XLSX file (also in Column A)
+
2) another CSV has many rows and column where is explanation for the first case (abbrevations), and I have to look for explanation inside that big file (so vlookup I used).
=
3) xlsx file is separate that has to combine both CSV into one, where on Column A I will have abbreviations and on Column B explanations of the certain terms.
I tried with functions and simply defining ranges:
Column A1 ='C:\Users\MirzaV\Desktop\1\[0528-matrix.csv]0528-matrix'!A3
Column B1 =VLOOKUP(A1;'C:\Users\MirzaV\Desktop\1\[variantendb.csv]variantendb'!$C:$D;2;0)
So seems nothing hard or else, but problem is I am having XXX of these CSV files and one main CSV file with explanations (it is stated as "varianten") , that are gonna be updated periodically - all of the files.
Instead to open three files at the same time just to refresh my functions, is it a bit quicker way with a code or other functions?? And I would like to have it in XLSX file.
I tried to record a macro but it didnt work good, I was thinking I can use it for rest of the files but always gives an error.
Application.Left = 2318.5
Application.Top = 89.5
Windows("0528-matrix1.xlsx").Activate
Range("A1").Select
ActiveCell.FormulaR1C1 = "='0528-matrix.csv'!R[1]C"
Range("A1").Select
Selection.AutoFill Destination:=Range("A1:A500"), Type:=xlFillDefault
Range("A1:A500").Select
ActiveWindow.Close
ActiveWindow.ScrollRow = 1
Application.Left = 2161
Application.Top = 1
Application.Width = 720
Application.Height = 780
Windows("0528-matrix1.xlsx").Activate
Range("B1").Select
ActiveCell.FormulaR1C1 = "=VLOOKUP(RC[-1],variantendb.csv!C3:C4,2,0)"
Range("B1").Select
Selection.AutoFill Destination:=Range("B1:B500")
Range("B1:B500").Select
Application.Left = 1896.25
Application.Top = 32.5
Application.Width = 864
Application.Height = 493.5
Windows("variantendb.xlsx").Activate
ActiveWindow.Close
Application.Left = 1669
Application.Top = 1
ChDir "C:\Users\MirzaV\Desktop\1"
Since you're using Office 365 we can use the Get & Transform feature to create links to your CSV files. As long as you maintain the same filenames on the CSVs, this will enable Excel to automatically update the data.
We'll complete this data merge in 3 stages:
Link the reference CSV (the second file you have listed) to a table
Link to the data CSV (the first file) to a table
Write an Index/Match function to pull the descriptions.
Stage 1: Linking the reference file to a table
In a new Excel workbook, click on the Data tab, then click on the New Query dropdown in the Get & Transform section. Mouse over "From File >" and select "From CSV"
Navigate to CSV 2 and click Import
On the next window that pops up, click "Load"
Your lookup data will now load into a table on a new sheet. Now let's clean up the references here:
Click on the Formulas tab, then Click on Name Manager
Select your new table (it will be named the same as your file)
Change the name to "Reference" and click Ok.
Go to your table and change the column names from "Column 1" and "Column 2" to "Abbr" and "Desc"
And that's it for stage 1! Now that we have the reference table set up and linked, we can move on to loading the data table we want to find the descriptions for.
Stage 2: Linking the data file to a table
We're going to link to the data file in the same way we did the reference file. Go to Data > Get & Transform > New Query > From File > From CSV. Select your file and click Import, then click Load.
On the new table, rename Column 1 to "Code" (I would use Abbr, but Code will help keep the next step looking clear).
Add another column to this table. The simplest way is to just click in B1, type "Desc" (or whatever name of your choosing) and hit Enter.
Stage 3: The Index function that makes the magic
On your new data table with the blank description column, click in the first data cell.
Type in the function =INDEX(Reference[Desc],MATCH([#Code],Reference[Abbr],0)) and press Enter.
Watch the magic happen as Excel copies our formula to every cell in that table column!
By setting up our CSV files as external connections in this manner, we're able to create a dynamic table that will always update with the CSVs.
By using Index/Match, we're able to get away from the constraints of VLookup (data in left-most field, sorted alphabetically), and move to a system that allows us to look for the value we need from any field in any order.
Breaking it down, Index returns the value of the cell provided in the target row and column of the specified array or table. Because we specified the target array as a single column of data, we can use Index([array], [row number]), or using the code above Index(Reference[Desc], [row number]). What really makes this work is the use of Match. Match returns the row number in an array of a target value, so we use MATCH([#Code],Reference[Abbr],0). This returns the row number to Index, which then pulls the data from the desired cell.
There are some additional steps we can do using the Power Query Editor to ensure the column headers always stay the same, but that's a tutorial for a different day. Hope this helps!
I have a sheet that the values of a range change each time I change a specific cell. Let's say that the cell C8 is an indentity of a person and column H the scheduled monthly repayments. I need to find the aggregate monthly repayments, hence on each possible value of C8 (and that actually means for every person as you can think of different values of C8) I need the aggegate of repayments, hence the aggegate of cell Hi Hence, keeping row i constant and changing cell C8, I always need to sum Hi. So I actually need sum(Hi) (i constant and the index of the sum is cell c8, so if c8 takes value from 1 to 200, I need the sum(Hi(c8)), again row i . Hi(c8) it is just a notation to show you that Hi depends on the value of c8. The actual formula in cell H10 is INDEX('Sheet2'!R:R,MATCH('Sheet1'!$C$8,'Sheet2'!F:F,0)))). H11 and onwards have the same formula with slight twists for the fact that the repayments are not always equal, but the index function remains the same.
Then, the total of H10 for all possible values of c8 is pasted in c17, the total of H11 is pasted in C18 etc. Please find some images below, maybe that helps to support what I try to achieve. enter image description here
I have the following code for that purpose. Note that the above example was just to explain you a bit the background, the cells and the range that changes are different.
sub sumloop()
Application.ScreenUpdating = False
Application.DisplayStatusBar = False
Sheets("Sheet1").Range("C8").Value = 1
Dim i, k As Integer
i = 1
k = Sheets("Sheet1").Range("C9").Value
Dim LR As Long
LR = Sheets("Sheet1").Range("C" &
Sheets("Sheet1").Rows.Count).End(xlUp).row
Sheets("Sheet1").Range("C17:C" & LR).ClearContents
Do While i <= k
If (Sheets("Sheet1").Range("J9").Value = "") Then
Sheets("Sheet1").Range("h10:h200").Copy
Sheets("Sheet1").Range("c17").PasteSpecial
Paste:=xlValues, Operation:=xlAdd, SkipBlanks:= _
False, Transpose:=False
Else
Sheets("Sheet1").Range("h9:h200").Copy
Sheets("Sheet1").Range("c17").PasteSpecial
Paste:=xlValues, Operation:=xlAdd, SkipBlanks:= _
False, Transpose:=False
End If
Sheets("Sheet1").Range("C8").Value = Sheets("Sheet1").Range("C8").Value+1
i = i + 1
Loop
Sheets("Sheet1").Range("C8").Value = 1
Application.ScreenUpdating = True
Application.DisplayStatusBar = True
End Sub
The if inside of the loop is needed as the location of the first value of the range depends on some criteria which have not to do with the code. Also k denotes the maximum number of possible values. What I need is approximately 250.
While the code works, it takes approximately 40 seconds to run for 84 values of cell C8 and approximately 1.5 minute for 250. I tried some things, changed do while to for but nothing significant, used variable ranges instead of fixed ones like h10:h100, very similar to what I do with Sheet1.Range(C17:C&LR). Again no significant changes. As I am very new to vba I don't know if 1.5 minutes are a lot for such a simple code, but to me it seems a lot and this analysis is needed for 10 different combinations of 250 different values for cell c8, which means 15 minutes approximately.
I would appreciate if anyone can suggest me something faster.
Thank you very much in advance.
Here is a complete solution, with explainations in comments.
Because we do not have you source spreadsheet, I could not run any tests on this.
Option Explicit 'This forces you to declare all your varaibles correctly. It may seem annoying at first glance, but will quickly save you time in the future.
Sub sumloop()
Application.ScreenUpdating = False
'Application.DisplayStatusBar = False -> This is not noticely slowing down your code as soon as you do not refresh the StatusBar value for more than say 5-10 times per second.
'Save the existing Calculation Mode to restore it at the end of the Macro
Dim xlPreviousCalcMode As XlCalculation
xlPreviousCalcMode = Application.Calculation
Application.Calculation = xlCalculationManual
'Conveniently store the Sheet into a variable. You might want to do the same with your cells, for example: MyCellWhichCounts = MySheet.Range("c17")
Dim MySheet As Worksheet
MySheet = ActiveWorkbook.Sheets("Sheet1")
MySheet.Range("C8").Value2 = 1 'It is recommended to use.Value2 instead of .Value (notably in case your data type is Currency, but it is good practice to use that one all the time)
Dim LR As Long
LR = MySheet.Range("C" & MySheet.Rows.Count).End(xlUp).Row 'Be carefull with "MySheet.Rows.Count", it may go beyond your data range, for example if you modify the formatting of a cell below your "last" row.
MySheet.Range("C17:C" & LR).Value2 = vbNullString 'It is recommended to use vbNullString instead of ""; although I agree it makes it more difficult to read.
Dim i As Integer, k As Integer 'Integers are ok, just make sure you neer exceed 255
k = MySheet.Range("C9").Value2
For i = 1 To k 'Use a For whenever you can, it is easier to maintain (i.e. avoid errors and also for you to remember when you go back to it years later)
'Little extra so you can track progress of your calcs
Dim z As Integer
z = 10 'This can have any value > 0. If the value is low, you will refresh your app often but it will slow down. If the value is high, it won't affect performance but your app might freeze and/or you will not have your Statusbar updated as often as you might like. As a rule of thumb, I aim to refresh around 5 times per seconds, which is enough for the end user not to notice anything.
If i Mod z = 0 Then 'Each time i is a mutliple of z
Application.StatusBar = "Calculating i = " & i & " of " & k 'We refresh the Statusbar
DoEvents 'We prevent the Excel App to freeze and throw messages like: The application is not responding.
End If
'Set the range
Dim MyResultRange As Range
If (MySheet.Range("J9").Value2 = vbNullString) Then
MyResultRange = MySheet.Range("h10:h200")
Else
MyResultRange = MySheet.Range("h9:h200")
End If
'# Extract Result Data
MyResultRange.Calculate 'Refresh the Range values
Dim MyResultData As Variant
MyResultData = MyResultRange.Value2 'Store the values in VBA all at once
'# Extract Original Data
Dim MyOriginalRange as Range
MyOriginalRange.Calculate
MyOriginalRange = MySheet.Range("c17").Resize(MyResultRange.Rows.Count,MyResultRange.Columns.Count) 'This produces a Range of the same size as MyResultRange
Dim MyOriginalData as Variant
MyOriginalData = MyOriginalRange.Value2
'# Sum Both Data Arrays
Dim MySumData() as Variant
Redim MySumData(lbound(MyResultRange,1) to ubound(MyResultRange,1),lbound(MyResultRange,2) to ubound(MyResultRange,2))
Dim j as long
For j = lbound(MySumData,1) to ubound(MySumData,1)
MySumData(j,1)= MyResultData(j,1) + MyOriginalData(j,1)
Next j
'Instead of the "For j = a to b", you could use this, but might be slower: MySumData = Application.WorksheetFunction.MMult(Array(1, 1), Array(MyResultData, MyOriginalData))
MySheet.Range("C8").Value2 = MySheet.Range("C8").Value2 + 1
Next i
MySheet.Range("C8").Value2 = 1
Application.ScreenUpdating = True
Application.StatusBar = False 'Give back the status bar control to the Excel App
Application.Calculation = xlPreviousCalcMode 'Do not forget to restore the Calculation Mode to its previous state
End Sub
Added by OP (see comments)
Image 1 Code written in the initially question. enter image description here
Image 2 Code above enter image description here
OK, A few things.
Firstly, Dim i, k As Integer doesn't do what you think it does, you need to do: Dim i As Integer, k As Integer
Secondly don't use Integer in VBA use Long so Dim i As Long, k As Long
Third the calculations are killing you. Turn them off with Application.Calculation = xlCalculationManual at the start of your code and back on with Application.Calculation = xlCalculationAutomatic at the end of your code.
Now we are presented with really fast code but the problem that it doesn't update on each iteration which you need it to do. You can calculate just a range like so: Sheets("Sheet1").Range("h10:h200").Calculate so put that in just before you copy the range
There will be an even faster way to do this but I just can't seem to wrap my head around your requirements so I am unable to assist further.
Welcome to StackOverflow.
I must admit I got a bit confused by your narrative, as I did not fully understand if you are doing a sum(a,b,c) or a sum(sum(a,b,c), sum(d,e,f), ...).
In any cases, a trick that will dramatically accelerate your script is the use of arrays.
Performing calcs with VBA is not slow, but retrieving the data from Excel (communicating with the application) IS slow, and pretty much depending on the number of "requests", rather than the quantity of data requested.
You can use arrays to request the data from a range all at once, isntead of requesting the value of each cell separately.
Dim Arr() As Variant
Arr = Range("A1:E999")
It is as simple as this.
Give it a try and if you are still struggling let us know.
BONUS
If you are new to Arrays, keep in mind you can have a two-dimmensionnal array:
Dim 2DArray(0 to 10, 0 to 50)
Or a stacked array (an array of arrays):
Dim MyArray() as String
Dim StackedArray() as MyArray
Dim StackedArray() as Variant
You will need a 2D-Array for extracting the data from a range, but I feel you may need an Array of 2D-Arrays for your Sum of Sums.
Some recommended reading: https://excelmacromastery.com/excel-vba-array/
How to achieve the same through pivot charts (no VBA)
Step 1
First, you must organize your data in a specific way, where each column is a field, and each row is a data entry. If you are not familiar with databases, this is the most tricky point as you may arrange your data in different ways.
Long story short, we will take an example where you have 3 customers and 4 dates.
So that is 12 data entries, which will provide the repayment value for each of the possible customer ID and date.
Step 2
Select that data and insert a PivotChart.
Note: you could insert a PivotTable alone, or a PivotChart alone. I recommend the option hwere you insert both, as managing your data will be more intuitive when working on the Chart. The table is updated at the same time you update the chart.
Step 3
Make sure the all your data is selected, including the top row which will dictate the name of each field (the name of each column).
Step 4
A new sheet has just been create, and you can see where both your PivotTble and PivotCharts will appear. Select the chart.
Step 5
A menu to the right will appear (it might have already been there, so make sure you selected the Chart and not the Table, as that menu would be slightly different).
Step 6
Drag and drop the field names into the categories as shown.
What you are doing here is telling Excel what data you want to see (Values) and how you want to break it down (per date, and per customer).
Step 7
By default dates data is always groupped quartile and year. To be able to see all the date we have data for, you can click the [+] near the data on the Table: this will show more details for both the table and the chart.
Step 8
But we want to get completely rid of the quartils and years. In order to achieve this, you need to right click any value of your date column in the Table, and choose "Ungroup" as displayed.
Step 9
Your data now looks like this.
Note the time axis is not on scale. For example if you hae monthly data and a month is missing, there will be no gap. This is one of the difficulties with Pivot data. This can be overcomes, but it is off topic here.
Step 10
Now we want to have a cumulative view of the data, so we want to play with the way the values are proessed by Excel.
Select the chart, then in the right panel: right click on the "Sum of Repayment" field, and select "Value Field Settings".
Step 11
In the "Show Values As" tab, select "Show values as" "Running Tital In".
Then choose "Date".
Here we are telling Excel that the value to display should be a cumulative total, cumulated according to the "Date" field.
Press OK.
Step 12
You now have what you are looking for. If you look in the Table, you have one column per Customer ID, and one row per date. For a given Date, you have the cumulative repayment made by a given Customer ID. At the very right, you have the Grand Total, which is, for a given date, the sum of all the Customer ID values.
Step 13
The Chart keeps showing the cumulative payment per CUstomer ID, and we cannot see the grand total.
In orer to achieve this, simply remove the "Customer ID" field from the "Legend (Series)" category area in the Fields Panel, as shown. (you can untick the Customer Id [x] box, or you can drag and drop it from the category area to the main list area).
Step 14
Now we only have the Grand total in the chart. But why?
If you display the "Value Field Settings" of Sum of Repyament" (Step 10), the first tab "Summarize Values By" will tell Excel what to do when several value meet the same Legend and Axis values.
Now that we removed the Customer ID field from the Legend area, for each date, we have 3 repayment values (one for each Customer ID). In the field settings, we tell Excel to use a "Sum". So it returns the sum of the 3 values.
But you could play around and return the Average, or even use "Count", which will show you how many records you have (it will return 3).
That is why pivot charts are so powerful: with only a few clicks and/or drag and drop, you can display a myriad of different graphics for your data.
For future interest, you should look online for Filters, and "Insert Slicer" (which is equivalent to filtering, but will add button directly on your chart: great when showing the data to colleagues and switch from one setting to another)
Hope this helped!
I have a VBA form which is used to enter data on a sheet. I am currently coding the form so as it will load any data already existing in the sheet back into the form.
For simple text strings it works perfectly.
e.g.
ReqSetup.ReqText = Application.Worksheets("Req Sheet").Range("F11").Value
However, I have some combo boxes, that on the form, when they are selected will enter a number in the corresponding cell.
Fail 1. - Run Time Error 380 - Invalid property value.
ReqSetup.MinPerKgCB = Application.Worksheets("Req Sheet").Range("C27").Value
Fail 2.
Dim MinPerKg As Range
Set MinPerKg = Application.Worksheets("Req Sheet").Range("C27")
ReqSetup.MinPerKgCB = MinPerKg
I'm obviously doing something really simple wrong but I can't work out what it is!!
Kind Regards!
I have some combo boxes, that on the form, when they are selected will
enter a number in the corresponding cell
Then you'd need to do the opposite of your code attempt, i.e.:
Worksheets("Req Sheet").Range("C27").Value = ReqSetup.MinPerKgCB.Value
That you'd better wrap inside a check that any combobox value is actually selected :
With ReqSetup.MinPerKgCB
If .ListIndex <> -1 Then Worksheets("Req Sheet").Range("C27").Value = .Value
End With
I have a dataset with 60+ thousand rows in excel and about 20 columns. The "ID column" sometimes repeats itself and I want to add a column that will return 1 only in the row that is the most recent only IF it repeats itself.
Here is the example. I have…
ID DATE ColumnX
AS1 Jan-2013 DATA
AS2 Feb-2013 DATA
AS3 Jan-2013 DATA
AS4 Dec-2013 DATA
AS2 Dec-2013 DATA
I want…
ID DATE ColumnX New Column
AS1 Jan-2013 DATA 1
AS2 Feb-2013 DATA 0
AS3 Jan-2013 DATA 1
AS4 Dec-2013 DATA 1
AS2 Dec-2013 DATA 1
I've been trying with a combination of sort and nested if's, but it depends on my data being always in the same order (so that it looks up the ID in the previous row).
Bonus points: consider my dataset if fairly large for excel, so the most efficient code that won't eat up processor would be appreciated!
An approach you could use is to point MSQuery at your table and use SQL to apply the business rules. On the positive side, this runs very quickly (a couple seconds in my tests against 64k rows). A huge minus is the query engine does not seem to support Excel tables exceeding 64k rows, but there might be ways to work around this. Regardless, I offer the solution in case it gives you some ideas.
To set up first give your data set a named range. I called it MYTABLE. Save. Next select a cell to the right of your table in row 1, and click through Data | From other sources | from Microsoft Query. Choose Excel Files* | OK, browse for your file. The Query Wiz should open, showing MYTABLE available, add all the columns. Click Cancel (really), and click Yes, you want to continue editing.
The MSQuery interface should open, click the SQL button and replace the code with the following. You will need to edit some specifics, such as the file path. (Also, note I used different column names. This was sheer paranoia on my part. The Jet engine is very finicky and I wanted to rule out conflicts with reserved words as I built this.)
SELECT
MYTABLE.ID_X,
MYTABLE.DATE_X,
MYTABLE.COLUMN_X,
IIF(MAXDATES.ID_x IS NULL,0,1) * IIF(DUPTABLE.ID_X IS NULL,0,1) AS NEW_DATA
FROM ((`C:\Users\andy3h\Desktop\SOTEST1.xlsx`.MYTABLE MYTABLE
LEFT OUTER JOIN (
SELECT MYTABLE1.ID_X, MAX(MYTABLE1.DATE_X) AS MAXDATE
FROM `C:\Users\andy3h\Desktop\SOTEST1.xlsx`.MYTABLE MYTABLE1
GROUP BY MYTABLE1.ID_X
) AS MAXDATES
ON MYTABLE.ID_X = MAXDATES.ID_X
AND MYTABLE.DATE_X = MAXDATES.MAXDATE)
LEFT OUTER JOIN (
SELECT MYTABLE2.ID_X
FROM `C:\Users\andy3h\Desktop\SOTEST1.xlsx`.MYTABLE MYTABLE2
GROUP BY MYTABLE2.ID_X
HAVING COUNT(1) > 1
) AS DUPTABLE
ON MYTABLE.ID_X = DUPTABLE.ID_X)
With the code in place MSQuery will complain the query can't be represented graphically. It's OK. The query will execute -- it might take longer than expected to run at this stage. I'm not sure why, but it should run much faster on subsequent refreshes. Once results return, File | Return data to Excel. Accept the defaults on the Import Data dialog.
That's the technique. To refresh the query against new data simply Data | Refresh. If you need to tweak the query you can get back to it though Excel via Data | Connections | Properties | Definition tab.
The code I provided returns your original data plus the NEW_DATA column, which has value 1 if the ID is duplicated and the date is the maximum date for that ID, otherwise 0. This code will not sort out ties if an ID's maximum date is on several rows. All such rows will be tagged 1.
Edit: The code is easily modified to ignore the duplication logic and show most recent row for all IDs. Simply change the last bit of the SELECT clause to read
IIF(MAXDATES.ID_x IS NULL,0,1) AS NEW_DATA
In that case, you could also remove the final LEFT JOIN with alias DUPTABLE.
Sort by ID, then by DATE (ascending). Define entries in new column to be 1 if previous row has the same ID and next row has a different ID or is empty (for last row), 0 otherwise.
It could be done in VBA. I'd be interested to know if this is possible just using formulas, I had to do something similar once before.
Sub Macro1()
Dim rowCount As Long
Sheets("Sheet1").Activate
rowCount = Cells(Rows.Count, 1).End(xlUp).Row
Columns("A:D").Select
Selection.AutoFilter
Range("D2:D" & rowCount).Select
Selection.ClearContents
Columns("A:D").Select
ActiveWorkbook.Worksheets("Sheet1").AutoFilter.Sort.SortFields.Add Key:=Range _
("B1:B" & rowCount), SortOn:=xlSortOnValues
ActiveWorkbook.Worksheets("Sheet1").AutoFilter.Sort.SortFields.Add Key:=Range _
("A1:A" & rowCount), SortOn:=xlSortOnValues
ActiveWorkbook.Worksheets("Sheet1").AutoFilter.Sort.Apply
Dim counter As Integer
For counter = 2 To rowCount
Cells(counter, 4) = 1
If Cells(counter, 1) = Cells(counter + 1, 1) Then Cells(counter, 4) = 0
Next counter
End Sub
So you activate the sheet and get the count of rows.
Then select and autofilter the results, and clear out Column D which has the 0s or 1s. Then filter on the values mbroshi suggested that you say you're already using. Then execute a loop for each record, changing the value to 1, but then back to 0 if the value ahead of it has the same ID.
Depending on your processor I dont think this would take more than a minute or two to run. If you do find something using formulas I would be interested to see it!