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Hi, I have an Ms access database file which give my user an opportunity to get it file path via OpenDialog control in VB.NET. Then I proceed the connection and SQL string to the table that I have design in Ms access. My Ms access table contain 1 table named tblTest with three field Id, Name and Sex. But sometime the user select difference database from OpenFileDialog control so the structure of database is difference. How could I write the code that check the database the user select have 1 table with 3 fields? Because I want to check the table structure before my application allow my user to continuse his/her work with it.
A thousand mile of journey, begin with the first step.
APO-CEDC
Save Children Norway-Cambodia Office
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If the file names for each file that the each user will be using are the same. I would suggest having the program recognizing that file name, and acting upon that.
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Thank you for your comment, But file name is not importance, the file could change to any valide name (but the extnesion .mdb must not change) but the structure (the number of table, field and relation structure) is the importance point. If user made a change to database structure, it would be problem when my application looking for the specific table to present the data it will have the problem.
A thousand mile of journey, begin with the first step.
APO-CEDC
Save Children Norway-Cambodia Office
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Well then your probably going to have some problems, as if each user as the ability to use Access to change the number,name of the tables then it could change at any point, and you'll be getting a call as to why this is happening. I'm not sure about your situation for this purpose, but i would suggest making it to where they can't change the content, and structure of the database without using your program. Then all you have to worry about doing is recognizing the names of tables and having your program act on that. The current situation, seems like it could be quite problematic if the user can change stuff regarding the database file.
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Thank you very much for your valuable idea, What I have to do are check the structure of database that user select whether it is the right database that I design. The second step is prevent my database from the user if they want to change the structure.
A thousand mile of journey, begin with the first step.
APO-CEDC
Save Children Norway-Cambodia Office
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Hi, I have a question relate to the file operation in VB.NET.
1. In VB6 if I want to .exe file I have to write the code call shell... But in VB.NET I have a button that will open the file (c:\abc.doc or c:\abc.xls or c:\abc.pdf). How could I write the code to open these file?
2. I want to preview the file (*.doc or *.xls or *.pdf) that I supply its location in RichTextBox control, how to I do that?
Please give me some sample to work with it
A thousand mile of journey, begin with the first step.
APO-CEDC
Save Children Norway-Cambodia Office
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Dim ProcID As Integer
' Run Calculator.
ProcID = Shell("C:\Windows\system32\calc.exe", AppWinStyle.NormalFocus)
' The preceding path is for Windows XP;
' The Windows 2000 path is C:\WINNT\system32\calc.exe.
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Thank you very much for your comment, but what I want is open Ms word file from VB.Net.
A thousand mile of journey, begin with the first step.
APO-CEDC
Save Children Norway-Cambodia Office
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The man from SCN-CO wrote:
2. I want to preview the file (*.doc or *.xls or *.pdf) that I supply its location in RichTextBox control, how to I do that?
You can't. The RichTextBox control knows nothing of the file formats for Word, Excel, or Acrobat.
RageInTheMachine9532
"...a pungent, ghastly, stinky piece of cheese!" -- The Roaming Gnome
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So, what should I do that? Do you have any other solution to recommend to me?
A thousand mile of journey, begin with the first step.
APO-CEDC
Save Children Norway-Cambodia Office
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I don't know of any component that will do this for you. Don't even think of interpreting these file formats yourself. Word and Excel use multiple stream OLE file formats that are extremely difficult to understand and parse, not to mention render on your own. Acrobat uses a simpler, single stream format, but documentation is difficult to find because you have to pay to get at the developer documents from Adobe.
RageInTheMachine9532
"...a pungent, ghastly, stinky piece of cheese!" -- The Roaming Gnome
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I read Visual Basic .Net Programming author by Harold Davis, ISBN: 81-7656-627-6. In chapter 9 on page 218 I fould that RichTextBox control control could read and display the content of *.rtf file. In my opinion, could I convert Ms word *.doc file to *.rtf file and open it in RichTechBox? Do you have any idea?
A thousand mile of journey, begin with the first step.
APO-CEDC
Save Children Norway-Cambodia Office
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It's entirely possible to do. But, since the .RTF format doesn't support alot of the formatting that Word does, the converted .RTF will not look the same as the Word version. Also, Excel doesn't export to an .RTF and neither does Acrobat AFAIK.
Also, if your going to go through the process of having Word convert the doc to RTF, why use a RichTextBox control to display the preview? Why not just use a visible Word control to do the preview?
RageInTheMachine9532
"...a pungent, ghastly, stinky piece of cheese!" -- The Roaming Gnome
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Dave Kreskowiak wrote:
It's entirely possible to do. But, since the .RTF format doesn't support alot of the formatting that Word does, the converted .RTF will not look the same as the Word version. Also, Excel doesn't export to an .RTF and neither does Acrobat AFAIK.
Yes, I think so RTF might not support as much as possible like Doc file. But the document that my user will use is type in a simple word document with Bold, Italic, Underline... but no graphic or any special formatted.
Dave Kreskowiak wrote:
Also, if your going to go through the process of having Word convert the doc to RTF, why use a RichTextBox control to display the preview? Why not just use a visible Word control to do the preview?
Because there a lot of document that will display for each topic, my user ask me for an opportunity to preview before they open the document that they want. I also have a sample code that I just check from the internet on how to open Microsoft word or excel from VB.Net. I could do it!!! but what I want is preview the file before my user open it.
I don't know that RichTextBox could support *.htm file or not but I have to try first if it is possible I might consider *.htm instead of *.rtf to preview in the RichTextBox control.
Thank you very much for your comment.
A thousand mile of journey, begin with the first step.
APO-CEDC
Save Children Norway-Cambodia Office
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The man from SCN-CO wrote:
I don't know that RichTextBox could support *.htm file
No, the RichTextBox doesn't support rendering HTML either. Just plain text or .RTF documents, that's it...
Getting a preview of all these document types is going to require a mountain of controls and code. Be sure that the end result is going to be worth the effort. If this functionality doesn't offer much to the main function of the application, it's probably not going to be worth it. At least, not in version 1.0...
RageInTheMachine9532
"...a pungent, ghastly, stinky piece of cheese!" -- The Roaming Gnome
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Ok, Thank you very Dave. Now I have an idea, I will put the field for my user to note any comment about the document that they add. So when they browse it they will see the note and remind them of is the content of the document that they add. Thank for your comment.
A thousand mile of journey, begin with the first step.
APO-CEDC
Save Children Norway-Cambodia Office
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And your going to store this information how and where? How are you going to retrieve the comment when the user selects the file?
RageInTheMachine9532
"...a pungent, ghastly, stinky piece of cheese!" -- The Roaming Gnome
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Dave Kreskowiak wrote:
And your going to store this information how and where?
I alread create a field in my database (ms access) with Memo datatype for my user to type any comment that they want.
Dave Kreskowiak wrote:
How are you going to retrieve the comment when the user selects the file?
Each document that I design in the table consist of ID, FilePath and Comment. So when the user select the file ID the path of the file with display on linklabel and the comment will display on the text box (and easy to update or delete). I think it is simple, do you think so?
A thousand mile of journey, begin with the first step.
APO-CEDC
Save Children Norway-Cambodia Office
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Hi, suppose that I have an Ms access database and I want to read its value from VB.NET and represent database to the form, I also want to perform the following basic action: Add new record, Update record and Delete record. Could any one give me a sample code (both for connect to the database and read/write the information from/to the database)?
A thousand mile of journey, begin with the first step.
APO-CEDC
Save Children Norway-Cambodia Office
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Imports System.data.oledb
Private sub ExtractData()
'connection
Dim oConn As New OleDbConnection
'command
Dim oCmd As New OleDbCommand
'dataset
Dim oDS As New DataSet
'dataadapter with command assigned
Dim oDA As New OleDbDataAdapter(oCmd)
'set connection string, you'll have to fill that bit in though
'should be easy to find if you don't know how to form it
oConn.ConnectionString = "Provider...."
oCmd.CommandType = CommandType.Text
oCmd.Connection = oConn
oCmd.CommandText = "SELECT * FROM Table1"
oDA.Fill(oDS)
'You then have a dataset to work with.
If you know SQL then you should be able to adapt that to perform all actions
Many Thanks
Harry
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Thank you very much Harry, Now I try to adapt with your code. I will let you know when I have a problem during my development process.
A thousand mile of journey, begin with the first step.
APO-CEDC
Save Children Norway-Cambodia Office
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I would like to add, to have this all take care of it for you. So it'll update I would suggest using the command builder componet.
Dim cmb As New OleDbCommandBuilder
oDA.SelectCommand = cmd2
Then add your row to the dataset, or modify it's data all you have to call is.
oDA.Update(ds)
That'll take care of your updates as it automatically fills in the Update, Add, Delete command strings for you. Hope this helps as a suggestion.
Gerry
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I have a little bit problem with ADO.NET. The reason that I have a problem is an experience with ADO from the ground. In VB6 I used to connect to database using vb6 and access database with DAO. I have used ADO for one time only with VB6 when I connect to SQL server. But it is one year ago and may be I have to check my source to make sure how it work. When I move to VB.NET I have a problem with OleDbDataAdapter and SqlDataAdapter and other component... (like DataTable, DataRow, DataSet...). I really difficult to figure out with this abstract technology. I think the only way that I should do is return to ADO and master it as soon as possible, than I might have a change to master ADO.NET in VB.Net.
A thousand mile of journey, begin with the first step.
APO-CEDC
Save Children Norway-Cambodia Office
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I'd say ADO.NET is much more different to ADO than ADO to DAO.
You're better off starting with ADO.NET right away if you don't need ADO.
Have a look at some MSDN articles on starting with ADO.NET, it's simple enough that you'll understand it in no time.
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