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I have this website application I've been working on, VB.NET .NET 3.5, everything works fine. I also need to develop a console application that updates the website's database. I use an Oracle 10g database.

I copied the same connection class I use on my main project, when I try to call the connection method I get this error:

The ConnectionString property has not been initialized.

Or this error if I don't use the class and call the code directly:

The 'OraOLEDB.Oracle' provider is not registered on the local machine

I have no idea why, the same connection works right now on my other project.

My connection class:

Public Class connection
 Public con As New OleDbConnection
 Public Sub connect()
  con = New OleDbConnection
  con.ConnectionString = "Data Source=localhost;User Id=system;Password=root;Provider=OraOLEDB.Oracle"
 End Sub
End Class

And when I call it:

connection.con.Open()
 sql.Connection = connection.con
 sql.CommandText = ...
 sql.CommandType = CommandType.Text
 reader = sql.ExecuteReader()
 While (reader.Read())
  ...
 End While
connection.con.Close()
user1676874
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  • Running an app developped for AnyCpu on x64 systems? – Steve Jan 28 '13 at 16:39
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    Well try to compile for x86. Probably your installed driver is for 32 bit OS and when you run in x64 systems with AnyCPU your code cannot use 32bit drivers. – Steve Jan 28 '13 at 17:52
  • I've tried this, now it says the connection must be open when I call the ExecuteReader method, but as you can see above the connection is being opened. – user1676874 Jan 28 '13 at 19:54
  • In you code above you don't call connect() and thus you should not be able to use that connection.con object, much less call open on it – Steve Jan 28 '13 at 20:07

2 Answers2

2

The problem stems from the fact that a code compiled for AnyCPU when is started on a 64 bit machine will be generated by the JIT as 64bit code and thus cannot use 32bit drivers. Simply recompiling the code for x86 platform will allow it to run as well on 32bit and 64bit systems and use 32bit drivers.

The second problem instead is caused by the fact that you don't call connect() and thus you should not be able to use that connection.con object, much less call open on it

Let me rewrite some of your code above

First, the class should be changed to 

Public Class Connection
    Private con As OleDbConnection
    Public OleDbConnection GetConnection()
        con = New OleDbConnection
        con.ConnectionString = "Data Source=localhost;" + 
                                "User Id=system;Password=root;Provider=OraOLEDB.Oracle"
        return con
    End Function
End Class

now the code could call the above class in this way

Connection cc = new Connection()
Using con = cc.GetConnection()
    con.Open()
    sql.Connection = con
    sql.CommandText = ...
    sql.CommandType = CommandType.Text
    reader = sql.ExecuteReader()
    While (reader.Read())
        ...
    End While
End Using

As you can see the class returns a correctly initialized connection when you call GetConnection() and you can use this object in a Using statement that serves the purpose of releasing the resources used by the connection when there is no more need of it.

Of course the Class Connection itself is pretty useless as is because you could write a simpler code directly on the code that need a connection without hiding the creation of the connection.
But if you plan to add more functionality....

Steve
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  • Oh yes you are right, I missed that part. There is however an issue when the program is run, it crashes and says vshost32.exe has stopped working, think it may have something to do with the connection?, since it's the only thing I have on my project. – user1676874 Jan 28 '13 at 21:10
  • Very difficult to say. A stack trace could help. And use the debugger of VS to find the exact line – Steve Jan 28 '13 at 21:12
0

Try to set your application debugging for x86 OS (32-bits)

Build -> Configuration Manager -> Debug -> Configuration:Debug -> Platform x86

Pellizon
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