Database choice?

[Guest Orion Tatsihama]

I'm creating a program and am trying to decide how to store the information entered. I want it to be able to be displayed in a noneditable way (but be able to be edited through another form). I would like to use a text file if possible...if not, I need an offline database. I know nothing about databases (except mySQL) and since this is going to be a distributed program, I don't want the user to need anything extra to use it. What is my best option?

 

I would like the information to be displayed in a grid, but not be editable through the grid itself. I would also like the user to be able to sort the data by any field, such as Title, Lenght, etc.

 

I am really new to all of this...so I'm sorry if I'm not being clear. Ask me if you need more information. I am using Visual Basic .NET

[Shurik12]

Hi,

 

displaying information in a grid, making it not editable, etc. has not very much to do with the choice of the database but rather with the the properties you're setting for the control displaying the data (think od DataGrid).

More over there are controls which intrinsically not meant for editing data displayed in it but for displaying it only (MSFLEXIGRID,MSHFLEXIGRID, ListView...)

For the rest, to give you a more precise answer, I think one needs to know more about your project.

 

About the fact you "don't want the user to need anything extra to use it"... Say, you can create a project with an Access database as a back end and after that distridute it on a PC which doesn't have Access on it.

 

Regards,

 

Shurik12.

[Guest Orion Tatsihama]

My program is called DVlog. It's a DVD "database" program where you enter information on dvds that you own and it keeps track of them. Right now, I'm just trying to get the Adding and Displaying features working. The fields are: Genre, Title, Rating, Length, (Number of) Disks, Special Edition? (Yes/No), and Year.

 

This is a demo entry in my text file database:

Anime\tGTO\tNR\t112\t1\tNo\t2002\tGreat Teacher Onizuka Ep. 1-4

 

More over there are controls which intrinsically not meant for editing data displayed in it but for displaying it only (MSFLEXIGRID,MSHFLEXIGRID, ListView...)

I hear a lot about MSFLEXIGRID and MSHFLEXIGRID but I have no idea what those are.

 

About the fact you "don't want the user to need anything extra to use it"... Say, you can create a project with an Access database as a back end and after that distridute it on a PC which doesn't have Access on it.

Yes, that's what I mean.

[Shurik12]

There are plenty of sights which might help you, I mean to give

a feeling where you have to go further.

 

Have a look at these ones:

 

http://www.gab2001uk.com/

http://www.gab2001uk.com/visualbasic/daovsado/index.htm

 

if you have more questions, don't hesitate to ask

 

 

Regards,

Shurik12.

[Guest Orion Tatsihama]

Will the fact that I use VB.NET Standart effect the use of the things on that site? I look at them and I don't see anything about DAO, AOD, or MSFlexigrids in my program. :(

[Shurik12]

The VB.NET syntaxis itself differs a good deal from that one of VB 6 (5...).

But the 'definitions' of ADO, Flexigrid etc. remain the same.

Try to have a look in the help files of your VB.Net Standard.

 

Regards,

 

Shurik12.

[Guest Orion Tatsihama]

Is it possible to use the text file 'database' I setup? Or an access database? I'm sorry...I'm really new when it comes to this stuff.

[Shurik12]

First of all you should not feel sorry. That's what forums are for: to ask questions and get answers.

 

If it's all about ONE 'table' you're going to have you can perfectly use your txt file as the 'data container'.

If you have more then one, then relational databases such as

Access, MS SQL, Oracle, Sybase, mySQL etc. come into play.

By the way you mentioned you had some experience with mySQL.

All the mentioned databases are relational. So there should be nothing new for you as far as the "idea" of a relational database concerned.

[Guest Orion Tatsihama]

That's good to know!

Now...I guess my only issue is taking the data in the text file and displaying it in a "spreadsheet" or "grid" type display. I also heard that you can't edit/delete a line of a text file, you have to rewrite the entire file omitting that line or replacing it with the edited line...is that true?

[Shurik12]

if you don't mind I'm going to have a nap. It's almost

2 a.m in Belgium. Will try to answer tomorrow (or some one else yet)

[Guest Orion Tatsihama]

No problem :)

Thanks for all your help!

 

To anyone who's reading this, feel free to help me out too, please. :)

[Shurik12]

Hi again,

 

If you choose a .txt-file as the place to strore the data, have a look at the "Open"-statement, "Input"-function, etc... in the help files. It should give you an idea how to work with the text files.

 

One more thing, if you have an opportunity to do it in Access or even in Excel go for it.

 

 

Regards,

Shurik12

[Guest Orion Tatsihama]

The main reason I want to use text files is cause I can use my own file extentions. :) I'll checkout the statements and functions. Thanks.

[Derek Stone]

One word: XML. Learn it. Use it. Enjoy it.

[Guest Orion Tatsihama]

I have no idea where to start with XML...

I looked at some XML resources but I don't get it.

[Guest mouseslinger]

To use a text file as a data container is simple.

 

Here is an example of how to open and read a text file in visual basic 6.

 

I don't have the .net version of visual basic , but it be similar in practice.

 

'----------------------------

' Example of how to open a file in visual basic.

'----------------------------

 

 

Dim importfile As Integer

importfile = FreeFile

 

Dim fileinfo as string

 

Open "c:\whatever.txt" For Input As #importfile

 

If Not EOF(1) Then

Do

Input #importfile, fileinfo ' get some info from the file.

Loop Until EOF(1) ' keep looping until its the end of the file.

End If

Close #importfile

 

 

 

'--------------------

 

This should give you an idea of what your code should look similar to.

 

Check in the help file for information on how to "open" a file.

 

Also look in the help files for examples of how to work with arrays.

 

If you would like, I would be happy to build a simple application using VB 6 which can read and write data to a text file, and post it online for download.

 

Would anyone else like me to build an example application for download?

 

david

mouseslinger@hotmail.com

[Guest mouseslinger]

To use a text file as a data container is simple.

 

Here is an example of how to open and read a text file in visual basic 6.

 

I don't have the .net version of visual basic , but it be similar in practice.

 

'----------------------------

' Example of how to open a file in visual basic.

'----------------------------

 

 

Dim importfile As Integer

importfile = FreeFile

 

Dim fileinfo as string

 

Open "c:\whatever.txt" For Input As #importfile

 

If Not EOF(1) Then

Do

Input #importfile, fileinfo ' get some info from the file.

Loop Until EOF(1) ' keep looping until its the end of the file.

End If

Close #importfile

 

 

 

'--------------------

 

This should give you an idea of what your code should look similar to.

 

Check in the help file for information on how to "open" a file.

 

Also look in the help files for examples of how to work with arrays.

 

If you would like, I would be happy to build a simple application using VB 6 which can read and write data to a text file, and post it online for download.

 

Would anyone else like me to build an example application for download?

 

david

mouseslinger@hotmail.com

[divil]

The .net version of that code is almost completely different, mouseslinger :)

[Guest Orion Tatsihama]

It is? Well I have no idea about converting it...I have the Standard version so it wouldn't convert it for my either. I found a script that can split the info from a file into an array, is there somewhay I can use that?

[Guest gjnave]

How to do it

 

The person who said that XML is the way to go is correct.. too bad he didn't say anything else about how to do it.

 

This is what I've done in an application of my own in which I save all my information in a "text" file as you put it (actually an .xml file; but can be read just as a text file in Notepad or whatever).

 

Try this:

 

First of all, on your toolbar click on "Project" and the click on "Add new Item".. from the list, choose "XML Schema".

 

This will add a new .xsd file to your program. In your program window go to that file and create a schema (a graphical representation and hierachal view of the way the data will be held). Press F1 to go to the help menu and read about Elements and Complex Types to create your schema.

Basically a schema is the "skeleton" of your database. It will give you something to populate. Once you start populating it you will save the results as a .XML file.

 

First of all put the following in the form that you are going to use to enter data.

This is how I coded it (not perfect as I am new at this also)

 

*( ' put this underneath "Inherits System.Windows.Forms.Form")

 

Public ds1 As New DataSet()

Dim xmlDoc As New Xml.XmlDataDocument()

 

*(' put this underneath your form load event) *

 

ds1.ReadXml(fileOpen)

 

'file open equals the name and location of the .xsd file you created... this loads the database structure into the dataset.

 

What you can do from here is tie the ds1 into a datagrid, of course you have to do this from code though.

 

datagrid1.datasource = ds1

 

 

Once you have entered whatever data into the datagrid, do this to save the information into a XML file.

 

private Sub saveXMLFile()

Dim sDialog As New SaveFileDialog()

sDialog.FileName = ("MyXMLFile") & ".xml"

sDialog.Filter = "XML files (*.xml)|*.xml"

If sDialog.ShowDialog = DialogResult.OK Then

Dim wstream As New _

System.IO.StreamWriter(sDialog.FileName)

ds1.WriteXml(wstream, XmlWriteMode.WriteSchema)

wstream.Close()

End If

End Sub

 

*note that "MyXMLFile" can be whatever you want

The file is now saved as an XML file. Pretty nifty!

 

Next make the form that you want to use to display the data.

 

'First of all create a datagrid on the view form and set its source to your dataset (you have to do this in code)

 

datagrid1.datasource = ds1

 

'Next, because you dont want anyone to be able to modify the contents of the database, set the read-only attribute to true.

 

datagrid1.readonly = true

 

Now, this is code to load the XML file:

 

Dim fsReadXml As New System.IO.FileStream _

("MyXMLFile.xml", System.IO.FileMode.Open)

' Create an XmlTextReader to read the file.

Dim myXmlReader As New System.Xml.XmlTextReader(fsReadXml)

' Read the XML document into the DataSet.

ds1.ReadXml(myXmlReader)

' Close the XmlTextReader

myXmlReader.Close()

 

 

The datagrid will be populated with the info you entered on your other form.

 

Hope this helped. Let me know if you need clarification.

[Guest Orion Tatsihama]

Thank you so much! I'll try that the first chance I get...stupid homework.

[Guest Eregnon]

If you'd like to just read in a text file, here's a class I put together that will do it. It just reads the file in and stores the result in a string variable, accessed through the filedata property. If there's an error, the errormessage property will be non-blank. Not much in the way of comments, but there's not much code either.

 

By the way, I'm also new at this. Then again, isn't everybody?

 

Public Class OpenForInput
   Private strFile As String
   Private intHandle As Integer
   Private strData As String
   Private strError As String

   Public Property FileName() As String
       Get
           Return strFile
       End Get

       Set(ByVal Value As String)
           strFile = Value
           If Dir(strFile) = "" Then
               strError = "File " & strFile & " not found."
               Exit Property
           End If

           Dim lngLength As Long
           lngLength = FileLen(strFile)

           strError = ""
           strData = ""
           intHandle = FreeFile()
           Try
               FileOpen(intHandle, strFile, OpenMode.Input, OpenAccess.Read, OpenShare.Default, )
               strData = InputString(intHandle, lngLength)

           Catch aru As System.ArgumentException
               strError = aru.Message

           Catch ios As System.IO.IOException
               strError = ios.Message

           Catch exe As Exception
               strError = exe.Message

           Finally
               FileClose(intHandle)
               If strError > "" Then   ' had an error
                   If strData = "" Then    ' means couldn't read file
                       strError = "Couldn't read file. " & Chr(13) & strError
                   Else
                       strError = "Couldn't open file. " & Chr(13) & strError
                   End If
               End If


           End Try

       End Set
   End Property

   Public ReadOnly Property ErrorMessage() As String
       Get
           Return strError
       End Get
   End Property

   Public ReadOnly Property FileData() As String
       Get
           Return strData
       End Get
   End Property

End Class

Edited September 14, 2002 by Derek Stone

[Guest Orion Tatsihama]

I went this gjnave's code and DVlog (which I replaced ds1 with, just the name) and ViewDVlog (which I replaced datagrid1 with) aren't valid...they have little blue underlines on them.

[Guest Orion Tatsihama]

Here's the code (forgot to post it).

 

Public Class Form
   Inherits System.Windows.Forms.Form

   Public DVlog As New DataSet()
   Dim xmlDoc As New Xml.XmlDataDocument()

[ Windows Form Designer generated code ]

  DVlog.ReadXml(fileOpen) 

   Private Sub saveXMLFile()
       Dim sDialog As New SaveFileDialog()
       sDialog.FileName = ("DVconfig") & ".xml"
       sDialog.Filter = "XML files (*.xml)|*.xml"
       If sDialog.ShowDialog = DialogResult.OK Then
           Dim wstream As New _
           System.IO.StreamWriter(sDialog.FileName)
           DVlog.WriteXml(wstream, XmlWriteMode.WriteSchema)
           wstream.Close()
       End If
   End Sub

   ViewDVlog.datasource = ds1 
   ViewDVlog.readonly = true 

   Dim fsReadXml As New System.IO.FileStream("DVconfig.xml", System.IO.FileMode.Open)
   ' Create an XmlTextReader to read the file. 
   Dim myXmlReader As New System.Xml.XmlTextReader(fsReadXml)
   ' Read the XML document into the DataSet. 
   DVblog.ReadXml(myXmlReader) 
   ' Close the XmlTextReader 
   myXmlReader.Close() 
End Class

I edited out the Windows Form Designer generated code (as you can see) because it made this post too long.

Edited September 14, 2002 by Derek Stone

[Derek Stone]

Eregnon, you might want to read the article below regarding file access.

 

http://www.elitevb.com/content/01,0072,01/01.aspx