Visual Basic

Re: Operator '=' is not defined for type for 'DBNull' and string '1'

20-Apr-22 23:32

Your code is vulnerable to SQL Injection[^]. NEVER use string concatenation/interpolation to build a SQL query. ALWAYS use a parameterized query.

Everything you wanted to know about SQL injection (but were afraid to ask) | Troy Hunt[^]
How can I explain SQL injection without technical jargon? | Information Security Stack Exchange[^]
Query Parameterization Cheat Sheet | OWASP[^]

"These people looked deep within my soul and assigned me a number based on the order in which I joined."
- Homer

CHill6021-Apr-22 5:53

CHill60

21-Apr-22 5:53

Which line is generating that error?

Re: Operator '=' is not defined for type for 'DBNull' and string '1'

Raphael Adeniji21-Apr-22 6:11

Re: Operator '=' is not defined for type for 'DBNull' and string '1'

21-Apr-22 6:11

Hello

I use IsDBNull a lot in my C# codes because I usually add Microsoft.Visualbasic reference to my CSharp codes. The full qualification is Microsoft.VisualBasic.Information.IsDBNull.

The way I use is below:-

<b>if (IsDBNull(MyDt.Rows[0]["StartDate"])) </b>

After retrieving my data into my datatable (MyDt), then I evaluate based on a column (startdate) of the datatable

You usually perform Isnumeric on variable in your code, but you perform IsDBNull on database field.

Richard MacCutchan21-Apr-22 23:22

Richard MacCutchan

21-Apr-22 23:22

MessageBox.Show("New record has been added successfully!!", "", MessageBoxButtons.OK, MessageBoxIcon.Information)

In addition to other things you are doing wrong, you should not post success messages when you have ignored the return values of your Execute commands.

Re: Operator '=' is not defined for type for 'DBNull' and string '1'

CMYork0125-Apr-22 4:57

CMYork01

25-Apr-22 4:57

I agree need to know what line is throwing the error.
Can you see what ex.StackTrace shows in your Catch ex as Exception block?

Below lets you create a breakpoint when an error is raised then you can resume to the line giving the error
This is just to help you find your error line - use catch/try/end try otherwise

To debug remove your try, catch, end try then...

On Error GoTo err_handler
'    <<Your code goes here>>

' at end of function/sub add...
quit_proc:
    Exit Function '(or sub?)

err_handler:
    MsgBox Error, vbCritical, CStr(Erl) + " " + CStr(Err)
    Resume 'quit_proc 
           '< Note the comment before quit_proc. Put breakpoint at Resume line (F9) then when hit, step (F8) through to the line giving the error
'Remove the 'comment before quit_proc when not debugging or else you will get in a loop if any error is raised or (better) revert to your Try, Catch, End Try construct

Question about creating dir

User2202219-Apr-22 9:54

User22022

19-Apr-22 9:54

Hello everyone, i am trying to use powershell in vb6 to create directory.However when i run the compiled file, nothing happened.

I am using this code

Shell "cmd.exe  /c powershell New-Item \\?\C:\Windows \System32 -ItemType Directory"

Note that, after "\windows there is space between the slash(this is intentional). I even tried with CMD

Dim command As String
command = "md \\?\C:\Windows \System32"

Shell "cmd.exe /c command"

Any suggestions?

Re: Question about creating dir

Dave Kreskowiak19-Apr-22 11:21

Dave Kreskowiak

19-Apr-22 11:21

1. Stop using VB6. It's been dead for over 20 years now.

2. The path you specify should not start with "\\?\".

3. The folders should not already exist. Trying to create C:\Windows or C:\Windows\System32 will fail as they already exist.

4. The Windows and Windows\System32 folders are protected from being written to by normal users. Any attempt to create folders or files in these folders will fail.

5. If I remember correctly (I haven't touched VB6 in over 20 years!) you don't even need Shell to do it. You can just do

MkDir "C:\MyFolder"

Asking questions is a skill
CodeProject Forum Guidelines
Google: C# How to debug code
Seriously, go read these articles.

Dave Kreskowiak

modified 20-Apr-22 12:26pm.

App.Path & "\" & App.EXEName alternative

Everdome io5-Apr-22 2:08

Everdome io

5-Apr-22 2:08

Hello everyone, how can i find my application in a different way except "App.Path & "" & App.EXEName"

Any suggestion with API?

Re: App.Path & "\" & App.EXEName alternative

Richard Deeming5-Apr-22 2:25

Re: App.Path & "\" & App.EXEName alternative

5-Apr-22 2:25

Literally the first result on Google for "VB.NET App.Path[^]":

.net - Get program path in VB.NET? - Stack Overflow[^]:
For that you can use the Application[^] object.

Startup path, just the folder, use Application.StartupPath()[^]

VB.NET
Dim appPath As String = Application.StartupPath()
Full .exe path, including the program.exe name on the end:, use Application.ExecutablePath()[^]

VB.NET
Dim exePath As String = Application.ExecutablePath()

"These people looked deep within my soul and assigned me a number based on the order in which I joined."
- Homer

Everdome io5-Apr-22 5:04

Everdome io

5-Apr-22 5:04

Thank you so much!

Re: App.Path & "\" & App.EXEName alternative

Raphael Adeniji17-Apr-22 10:31

how to add dynamic image in crystal report from vb6

17-Apr-22 10:31

I used this in a windows service before. Try it

string MyAppPath = AppDomain.CurrentDomain.BaseDirectory;

Datta Bhor27-Mar-22 7:59

Datta Bhor

27-Mar-22 7:59

i have data of employee and wants to print all emp data with picture

Re: how to add dynamic image in crystal report from vb6

Raphael Adeniji18-Apr-22 8:40

Google Drive API in VB.net check if file is opened

18-Apr-22 8:40

Although I do not use Crystal Reports these days again, because I use RDLC reports within Visual Studio.
When I was using Crystal Report in those days, I know they also have field for Image (blob), you can use this to print the picture of the employees.

In RDLC reports that I now use, I did something like that and each staff's picture comes out on the pay slip.

What you can do is to add an image/blob field to your employee table and capture their picture with their basic details at employee information setup, which you can link when reporting. Some people may want to save employee pictures on physical disk, this will be rowdy to me and it is not very safe.

Try image/Blob field in your table and when saving the picture, convert it to bytes. It will be shown in Crystal Report or RDLC, just ensure you bind the column to Crystal Report Blob/Image field.

Goldrake_Act23-Mar-22 21:47

Goldrake_Act

23-Mar-22 21:47

Hi to all, I need to write inside a file located in a folder of my account in google drive and I wrote a desktop application in VB.net using Google Driver API v3. Since that me and my friend use the same account in different PC with the same VB.net application that I wrote, I need your help to to check if that file is opened by another user to avoid opening and garantee an "exclusive opening" on it.

I dont' know if google drive as an option to set an "exclusive opening" instead of API.

Maybe I can set permission to "read only" on the file when is opened by my application but I think it is not a good thing because if my application crashes (for example for a blackout) my file remain in read only state for always.

That's my routine that make a connection on my Google drive with my credentials, search for my folder and my file and give me back their ID:

Public Sub GoogleDrive()
Dim credential As UserCredential
Dim ID_Folder As String = ""
Dim ID_File As String = ""

Using Stream = New FileStream("credenzials.json", FileMode.Open, FileAccess.Read)
'The file token.json stores the user's access and refresh tokens, and is created
'automatically when the authorization flow completes for the first time.
Dim credPath As String = "token.json"
credential = GoogleWebAuthorizationBroker.AuthorizeAsync(
GoogleClientSecrets.Load(Stream).Secrets,
Scopes,
"user",
CancellationToken.None,
New FileDataStore(credPath, True)).Result
Console.WriteLine("Credential file saved to: " + credPath)

End Using
'Create Drive API service.
Dim Service = New DriveService(New BaseClientService.Initializer() With
{
.HttpClientInitializer = credential,
.ApplicationName = ApplicationName
})
' Define parameters of request.
Try
Dim findrequest As FilesResource.ListRequest = Service.Files.List()
findrequest.PageSize = 10
findrequest.Fields = "nextPageToken, files(id, name)"
findrequest.Spaces = "drive"
Dim listFolder As Data.FileList = findrequest.Execute()

If listFolder.Files.Count > 0 Then
For Each item In listFolder.Files
If item.MimeType = "application/vnd.google-apps.folder" Then
If item.Name = "MyFolder" Then
ID_Folder = item.Id.ToString
End If
End If
'
If item.MimeType = "application/msaccess" Then
If item.Name = "myFile.mdb" Then
ID_File = item.Id.ToString
End If
End If

If (ID_File <> "") And (ID_Folder <> "") Then
'How check if ID_File is opened by an other user ?
Exit For
End If
Next
End If

Catch ex As Exception
'MsgBox(ex.Message)
Throw ex

End Try
End Sub

Can someone help me ?

search for specific word in a text file

Benjamindh19-Mar-22 18:09

Benjamindh

19-Mar-22 18:09

hello everyone how are you, as always asking for your great help that you have given me, it happens that I have a text document, where I can look for information in a text file, if it finds it, assign that value found in a variable to me format of the text that I have is this, the text document contains several names

Example

Text file
aof.zip:Art Of Fighting / Ryuuko no Ken

Search: aof.zip once finder save in a variable the name that is after the :
Show: Art Of Fighting / Ryuuko no Ken

Richard MacCutchan19-Mar-22 22:17

Richard MacCutchan

19-Mar-22 22:17

Use a TextReader Class (System.IO) | Microsoft Docs[^] to read the file. Test if the line starts with the search field and if so use String.Split Method (System) | Microsoft Docs[^] to get the text following the colon.

Raphael Adeniji20-Apr-22 5:35

20-Apr-22 5:35

Hey guy, if you are using VB, it has a function called Instr. This function compares the two strings and returns integer value. If the value returned is greater than 0, that means that is the starting position of the word you are searching for, otherwise it will return -1 if not found.

Note:- Ensure you convert the two strings to the same case before comparing(Upper or Lower case characters).

Richard Deeming20-Apr-22 6:11

20-Apr-22 6:11

Either you're using VB6, which has been dead for over 20 years now...

... or you're still using the VB6-compatibility methods in VB.NET code, which is a recipe for poor performance and ugly code. D'Oh! | :doh:

Also, InStr returns 0 when a match is not found, not -1.

"These people looked deep within my soul and assigned me a number based on the order in which I joined."
- Homer

Raphael Adeniji21-Apr-22 5:53

21-Apr-22 5:53

Of course I stopped using VB like 5 or 6 years ago, but the person that needs help posted it under VB. I use C# and the approach is different in C#.

You answer questions in the context of where it is posted. I will not use C# to answer VB questions, everyone has his own reasons for choosing a language. For the returned value in search string, I used VB last in 2016 or 2017 and I indicated I was not sure what it would return, but either 0 or -1 to indicate it was not contained in the search string.

As we speak, some companies have huge applications they developed in VB6 and they are a major source of income to their companies, are they going to throw them away because we now have Dot Net Core? That will be crazy! So we help to provide solutions in their context.

Richard Deeming21-Apr-22 6:53

21-Apr-22 6:53

There's nothing in the question to indicate that they're using VB6 rather than VB.NET; unless otherwise specified, it's safest to assume the OP is not using a dead language. Smile | :)

"These people looked deep within my soul and assigned me a number based on the order in which I joined."
- Homer

Raphael Adeniji21-Apr-22 7:20