[RESOLVED] A problem when saving the data

I will have a program which will save the equipments into the text file and I have a button which increases the number of the equipment. That button works now, but I want the program to save the new number. For example,
First,

Resistors 15
Control cards 22

I increased the the number of resistors. It's 16 now. I want to save it after deleting the old data

Then,
It should be

Resistors 16
Control cards 22


when I try to do this, it will be

Resistors 15
Control cards 22
Resistors 16


How can I solve this problem?

Thanks

here is a theoretical solution:
1. read both lines
2. make the necessary changes to the data
3. empty the file (delete and recreate/open to overwrite)
4. write the data

hope this helps.

it depends on how you handled the file in the first place as we can see what you did we are shooting in the dark

more info needed
here to talk

I have a command buttons called save and increase and I have combobox and text box.

I select resistor from combobox and I write 10 in textbox and I click the save button. The program writes into the file

Resistor 10


After that, I select resistor from combobox and I click increase button. It writes

Resistor 10
Resistor 11

I want it to write

Resistor 11


What should I do?

You cannot simply change text within a file unless what you are changing results in the exact same number of characters. Even so, doing so is a bit of a pain. There are 2 common methods, among others, that people generally use

1) Read the entire file into memory. Change what is needed. Re-write the entire file. Similar to what mebhas mentioned in reply #2

2) Open 1 file for reading, another for writing. Read a line from 1st file, modify it if needed, write the line to the 2nd file. Close both files when done. Delete 1st file & rename 2nd file to 1st file's name.

I couldn't find a solution that's why I copy the code

vb Code:

If category2 = "" And category3 = "" And category4 = "" Then
    
        Open "D:\\test.txt" For Input As #1
        Do While Not (EOF(1))
            Input #1, read
            a = Mid(read, 1, M)
            M = Len(read)
            If InStr(1, read, category, 1) <= 0 Or InStr(1, read, equip_number) <= 0 Then
                MsgBox "There is no record like this, please check the number and the name of category"
                Exit Sub
           
            ElseIf InStr(1, read, category, 1) > 0 And Mid(read, M - 1, 1) = " " And InStr(1, read, equip_number, 1) > 0 Then
       w = Right(read, 1)
 
        
        Exit Do
        
    ElseIf InStr(1, read, category, 1) > 0 And Mid(read, M - 2, 1) = " " And InStr(1, read, equip_number, 1) > 0 Then
w = Right(read, 2)
 
        Exit Do
        
    ElseIf InStr(1, read, category, 1) > 0 And Mid(read, M - 3, 1) = " " And InStr(1, read, equip_number, 1) > 0 Then
w = Right(read, 3)
 
        Exit Do
        
    ElseIf InStr(1, read, category, 1) > 0 And Mid(read, M - 4, 1) = " " And InStr(1, read, equip_number, 1) > 0 Then
w = Right(read, 4)
 
        Exit Do
       
    ElseIf InStr(1, read, category, 1) > 0 And Mid(read, M - 5, 1) = " " And InStr(1, read, equip_number, 1) > 0 Then
w = Right(read, 5)
 
    Exit Do
     
    End If
    Loop
    Close #1
 
    a = " "
    Text_number_of_equipment.Text = w + 1
    End If
 
    Open "D:\\test.txt" For Append As #1
        Print #1, category, equip_number, w
        Close #1

category = the name of equipment
equip_number = the number of equipment to distinguish the other products which have the same name
number_of_equipment = it means how many product I have

Firstly, I tried to check the file to decide if it's written in the text file. After that I find the number of equipment and I increase it and I change the line ( because I will write new ) and I write the new line

Where is the mistake?

This seems to be very complicated for a simple problem. It appears that you are searching the record for the last space in order to isolate the Count. InStrRev is useful for such things. (It searches a String in reverse) Also, there's no need for the 'complex' If statement if you reverse the logic. As has been previously stated, you can't selectively update records, in-situ, in a sequential file, you have to replace the entire file. Opening a file for 'Append' just adds new records to the file.

You could re-work the file format into fixed length records and use Random Access where you can select records by record number and update in-situ, but for some reason, that's not very popular these days. I guess the advent of sophisticated (and free) Databases is one of the main reasons coupled with the 'housekeeping' you'd have to do to keep the file 'tidy'. If your file is getting, or is likely to get, large, then the Database option may be the way forward.

Here's something you can play with, which goes along the lines of previous suggestions.

It's untested but hopefully you can follow the logic by reading the comments. I think there's more lines of comments than code :)

Code:

---

Dim boUpdate As Boolean
Dim boErr As Boolean
Dim intFile As Integer
Dim intI As Integer
Dim strData As String
Dim strT As String
Dim intN As Integer
Dim intP As Integer
Dim strRec() As String
'
' Whatever your preamble code is
'
If category2 = "" And category3 = "" And category4 = "" Then
    '
    ' Allocate a File Number
    ' Open, read the entire contents of the file and close it
    ' Split the data into records
    '
    ' It is assumed that:
    '  (a) Each Record is unique
    '  (b) The Count is the last item of data in the record preceded by a space
    '      eg "Resistor 1.2K 0.5W 0.1% High Stability ENR1.2.5.1.H 17"
    '      Where: 17 is the current Count
    '      and, for example, 'Resistor' is the Category, and 'ENR1.2.5.1.H' is the equipment number
    '
    intFile = FreeFile
    Open "D:\Test.txt" For Input As intFile
    strData = Input(LOF(intFile), intFile)
    Close intFile
    strRec = Split(strData, vbNewLine)
    Do
        '
        ' If this record's category and equipment number match
        ' the ones being searched for:
        ' Isolate the count, increment it and replace the record to include
        ' the new updated count
        ' Set the flag to exit the loop
        '
        If InStr(strRec(intI), category) > 0 And InStr(strRec(intI), equip_number) > 0 Then
            '
            ' Locate the last space character in the record
            ' which will be just in front of the Count
            '
            intP = InStrRev(strRec(intI), " ")
            If intP > 0 Then
                '
                ' Check that the Count is numeric
                ' and increment it if it is
                '
                If IsNumeric(Mid$(strRec(intI), intP + 1)) Then
                    intN = CInt(Mid$(strRec(intI), intP + 1))
                    intN = intN + 1
                    '
                    ' Copy the first part of this record to a temporary string
                    ' add the new count and replace the existing Record
                    ' in the array. Display the new Count in the TextBox
                    '
                    strT = Mid$(strRec(intI), 1, intP) & CStr(intN)
                    strRec(intI) = strT
                    Text_number_of_equipment.Text = CStr(intN)
                    boUpdate = True
                Else
                    '
                    ' The existing value is not numeric or is not present
                    ' report the fact and exit the loop
                    '
                    MsgBox "Invalid Count in Record or Count Not Found" & CStr(intI + 1)
                    boErr = True
                End If
            Else
                '
                ' This record did not have an existing count
                ' report the fact and exit the loop
                '
                MsgBox "Did not find a Count for Record " & CStr(intI + 1)
                boErr = True
            End If
        End If
        intI = intI + 1
    Loop Until intI > UBound(strRec) Or boUpdate = True Or boErr = True
    '
    ' If no match was found, report the fact and finish
    '
    If intI > UBound(strRec) Then
        MsgBox "No matching record found for " & category & " " & equip_number
    Else
        '
        ' If an update was made, re-write the
        ' entire file. Tell the user it's been done
        '
        If boUpdate Then
            intFile = FreeFile
            Open "D:\test.txt" For Output As intFile
            For intI = 0 To UBound(strRec)
                Print #intFile, strRec(intI)
            Next intI
            Close intFile
            MsgBox "File has been Updated"
        End If
    End If
End If

---

oops

the test for category emtyness

if category1&category2&category3="" then ' ""&""&"" = ""

the complex

if
elseif
elseif
end if

should really be

select case
case
case
end case

the latter escapes when tasks are done and is a flatter structure easier to read

here to help

it was about category1, category2, category3. They must have been combo1.text, combo2.text, combo3.text.

Thanks for replies