I created a connection class that should return a datatables/datareaders etc to my webpages. I am worried that the connections won't be closed properly by using this class. Here is the class: [code]I am worried that once I go into production the connections won't be close properly and my site will fail. I am new to .net, is there anything wrong with the principal behind this class?
View 3 RepliesI want to create a class in vb.net that make the connection to database.Also I need the way to use this class inside forms. I need a code example of both the class and the form call
View 1 RepliesI know I'm missing something really simple here, but I'm trying to create a class that I can use to access the database in my program as this is obviously used a lot throught out the program and on different forms. I've used classes for other purposes and never had a problem but for what ever reason I can't seem to get this one to work.[code]...
View 1 Repliesim making a class.vb which has a sql connection. The class.vb will be used by all forms/windows on the application. So whenever a form needs to access the database, it will call class.vb.
This is the code in class.vb:
Public Sub Openconn()
Dim myConnection As SqlConnection
Dim connstring As String = "Data Source=192.162;Initial Catalog=db1;User Id=sa;Password=1;"
[code]....
but it gives error: value of type sqlconnection cannot converted to array of Sqlconnection.I just want a method that's useful for opening the connection and that is also useful when asigning to a command object.
I tried to make my ODBC Connection within the class. here's my class code
Public Class Library
Public Function Seek(ByVal Connection As Odbc.OdbcConnection, ByVal TableName As String, ByVal Field As String, ByVal Index As Long)
[Code]....
Here's my error: Unable to cast object of type 'System.Int32' to type 'System.Data.DataSet'. I am using VBdotNet2005
Trying to begin rewriting a VB6 application using .NET (as a Windows Forms app.) to get some practical coding experience.First hurdle is the best way to connect from VB.NET to typically various stored procedures in a SQL Server DB... I'm of course struggling a little along the way as well w/the difference in syntax and so forth, too.Anyone out there have an example you can point me to as far as typical blocks of code you use in calling to establish connectivity to SQL Server databases, populate SQLDataAdapter objects, etc?My assumption is that I need to create a connection object class and have everything in there and just call various methods of that connection object class whenever I need to connect to the database, retrieve data from stored procedures to populate fields on various screens of my app., close the connection to the database, etc.
View 4 RepliesI've got a fairly large VB.NET (3.5) project that makes a lot of database calls. So I created a namespace/class just to handle those fuctions. The idea was that this single point of entry into the database would give more control over validating input from users.
So my class looks something like this. (I've chopped some code out for readability, it works just fine except for all the open connections.
[Code]...
So I can close the data reader, but how do I reach back to that original database class and close the connection. If I close it in that original class it will bomb when I try to loop through the data reader the in calling class.I'm sure this is probably pretty obvious but I'm fried from the keyboard.
I am working on designing a SQL Server database connection class in VB.net 2005. The idea behind doing this will be so a developer can can call the class, pass it a stored procedure name along with the parameters, and get return values back (if any).
View 1 RepliesIs there a (simple) way to connect a textbox, label etc. to a property in a class?I have a project with a complex series of dialogs to enter data into a list of a costum class describing an experiment with many parameters that are stored as properties (both simple variables such as strings and integers, but also more complex ones).I need both to be able to update the list of my experiment class, but also to go the other way to populate the dialogs from the class.It can of course be done outside the class and the dialogs in separate subroutines. This however, quicly becomes unmanagable and hard to maintain as the dialogs and experiment class is expanded with new elements.If there was a simple way to connect say a textbox or label in a dialog with the appropriate property holding the information it would make it much easier.
View 5 RepliesIn my application I have many different forms each use 3 different database. And right now I am placing the connection string in each form but when it is need to change I have to change in every form. Now what I want to store all connection string in a vb class and call them in every form. So that if I need to change I can do in that class. I have stored my connection string in database so even I don't want to connect to database again and again. I have some idea in which maybe a public class is used and some how I will call it on other forms.
View 2 RepliesIn my earlier project I was able to change the connection string during the app settings loaded event and it was successfully. When I try to do the same for a code library project, I am not getting the system.configuration.connectionstringsettings to work. Could you please tell if there is a work around for this, or else it is always better to write the sql code instead of depending on the adapters etc.
Additional information: Clients App is WPF with Vb. Database is SQL Server 2008 Code Lib would only be on server, slq connectiona and data retrieving and saving actions are stored in classes in code lib only. Code Lib would be used with WCF, wcf is used to share the classes only and classes have the data. WCF is hosted as a windows service on server used by NET.TCP
I am try to learn to use Mysql / MySql.Data.MySqlClientI did find sample how to connect to Mysql but I want to have it in Class or Module so I only call open database when I open the form
How can I fix this Name 'connStr' is not declared
CODE:
You can change the connection string at run-time like this. You make the connection string setting available for writing as a separate property inside the MySettings class:
Partial Friend NotInheritable Class MySettings
Public WriteOnly Property RunTimeConnectionString()
Set(ByVal value)
[code]....
Then, in some place when the application is being initialized (before using any table adapters of typed datasets), write something like:
My.Settings.RunTimeConnectionString = My.Settings.ProductionConnectionString
Where ProductionConnectionString is a simple String setting. It is a User Scope setting so every user can change it (by assigning a value to it, similar to the code above) and save it by calling My.Settings.Save()This code works well for connection strings which were initially created in the main project and stored in it's settings (= app.config file).
The connection string in the app.config actually has a longer name: MyApp.MySettings.MyConnectionString.When you have a connection string stored in the app.config in a class library project, and reference that project in the main project, the app.config files will somehow be merged, so the class library has it's settings.The thing that don't know how to do, is change a setting from the class library at run-time. I could copy the connection string setting from the class library to the main project's app.config. I must keep the same name, which looks something like: MyClassLibrary.My.MySettings.MyConnectionString.Can the same principle I showed above be somehow applied to this second connection string?
Example data arrival: 07:05 -!- [URL] 366 name #test :End of /NAMES list. 07:05 -!- etc.... If i debug.writeline the returning value or use a messagebox both will display the out put above. If i try return using an if statement matching against the Nothing keyword. It will still be displayed.
View 8 RepliesHow do I assign a My.Settings.Item connection string to cmd.Connection connection string value?
Dim cmd As New SqlCommand()
cmd.Connection = My.Settings.Item("csStaffHoursWorked")
cmd.CommandType = CommandType.StoredProcedure
cmd.CommandText = "spSaveDeltekImport"
I compiled some VB6 code on my Win7 x64 machine and the result .exe will not run correctly on any other machine. VB6 code is just a new template .exe file with one button, a reference to "Microsoft ActiveX Data Objects 2.6 Library" and the following code in the button press event: Dim db Set db = New ADODB.Connection It runs correctly on my machine, but no others (even other Win7 x64 machines) (Update: I found TWO other users where it runs and one of them is Jeff Atwood!, but most machines have the same problem)
[Code]...
If Class X is within the scope of Class Y, is X a subclass of Y?If Class A is a sub Class of B, then is Class B considered a super class of A?if Class C inherits Class D is Class D a superclass or parent of Class C?if Class E extends Class F then we can consider Class E a child of F?if Class G inherits Class H and is within the scope of Class I then who is the parent of Class G? Classes that inherits Class J and classes that are within Class J are all sub classes of Class J?
View 1 RepliesIs there a way to display the connection properties dialog for connection string browsing(for database) in run time?
As I want the user to be able to connect to various database using the GUI.
i have an application. which is executed after every 5 mins. i have an open connection but it gives me the following error:
ExecuteScalar requires an open and available Connection. The connection's current state is closed.
my code is something like this. I have shown where all i am using ExceuteScalar()
Sub Main()
Try
connection.open()
cmd.ExecuteScalar()
[code]....
After running the following sub (VS debugger), I try to detach the database in SSMS, but it shows the connection open still and won't let me detach. If I close program in debugger, the database shows no connections. I check the dataadapter's connection in the finally block and is shows closed. What gives
Private Function ClientMasterDBFiles(ByVal MasterClientDBConnection As String, ByVal DBName As String) As DataTable
[Code]...
I have a simple scraper. It works on some websites, but on some there is this Error:
Quote:
IOException was unhandled Unable to read data from the transport connection: The connection was closed
It is occuring at "Dim htmlresults As String = Urlcontents.ReadToEnd()".
'Create the HttpWebRequest object
Dim req As HttpWebRequest = WebRequest.Create(URL)
'Set the timeout to 1 second (or 1,000 milliseconds)
req.Timeout = 10000
[code]....
I am attempting to write a program that will disable the Local Area Connection while leaving the Wireless connection enabled. My company is using net-books in our stores to demo air-cards and we need to keep them off of the LAN. I'm new to VB and VB.net, and it's been a while since I did any type of programming. I've gathered some code that others have posted in forums and tutorials and I'm working through a tutorial book, but I finally believe that I am stuck.
[Code]...
i make a class and when i call on form then that error occurs "ExecuteNonQuery requires an open and available connection, the connection Current stat is close "
Class Code isImports System.Data.SqlClientImports System.DataImports System.StringPublic Class DatabaseKits Dim Cn As New SqlClient.SqlConnection Public Function BuildConnection() As Boolean Try Cn.ConnectionString = "Persist Security Info=False;Integrated Security=True;Trusted_Connection=Yes;database=BizAimsPro2008;server=Server-2k3s" BuildConnection =
[code]....
I am connecting to a data stream that pushes data continuously and when I tried to set up a network stream I just could not connect and kept getting the 'not found' error. I used the httpwebrequest with webrequest.keepalive = true and started to consume the data by reading into a buffer and then appending to a stringbuilder. Once the stringbuilder reaches max size I flush it to a text file. The problem is that I get disconnected from the data stream because I am not reading the data fast enough. I need to keep the connection open and read the data while ensuring data gets stored in text files. If I use method "CONNECT" it does not connect to the stream.
While (True)
webrequest = DirectCast(Net.WebRequest.Create(url), HttpWebRequest)
webrequest.Credentials = New System.Net.NetworkCredential(username, password)
webrequest.Method = "GET"
[code]....
should I increase the buffer size and if so what is the max? that would mean I can read more data at a time and keep up with incoming push. Disparate here.
ACtually also I noticed that it gets stuck on this line
numbytesread = responseStream.Read(bufferread, 0, BUFFER_SIZE)
and then eventually I get disconnected.
I am connecting to a data stream that pushes data continuously and when I tried to set up a network stream I just could not connect and kept getting the 'not found' error. I used the httpwebrequest with webrequest.keepalive = true and started to consume the data by reading into a buffer and then appending to a stringbuilder. Once the stringbuilder reaches max size I flush it to a text file. The problem is that I get disconnected from the data stream because I am not reading the data fast enough. I need to keep the connection open and read the data while ensuring data gets stored in text files.If I use method "CONNECT" it does not connect to the stream.[code]
View 1 RepliesI understand the possibilities for encrypting a connection string in .net v4. I have a win forms application that will be used by multiple people on different machines. I understand that I need to protect the connection string at time of the app being first run on the target machine. However I am concerned that for a period of time my connection string will be unencrypted. I am looking for advice in how to deploy my app with the connection string already encrypted or encrypted during installation. encrypting the connection string in a secure way?
View 1 RepliesI have put this code in the global form Inherits System.Windows.Forms.Form. And then in the form that will inherit this from the global Inherits MenuStrip. "MenuStrip" is what the global form is called. But keep getting this error: Error1Base class 'MenuStrip' specified for class 'Lesson2' cannot be different from the base class 'System.Windows.Forms.Form' of one of its other partial types.
View 5 RepliesTry If functionmode = "ADD" Then
[Code]...
I got this error..The connection was not closed. The connection's current state is open.
This is coding to add data in Ms access in vb...
Imports System.Data.OleDb Public Class Form1
[Code]...
I'm developing a device app in VB.net that will access a SQL Server database. I need to establish a connection when the app is launched, and keep the connection open until the app is closed. I've done the following:In the Master Module:
Public CNN
As SqlConnection
In the Main menu form load:
CNN =
New SqlConnection(sqlConnString)
CNN.Open()
Then when I want to read from the database:
Dim sqlDR
As SqlDataReader
SQL = "SELECT Name FROM Table"
[code]....
When I run the same code without the global CNN, but rather dim the connection inside the Select function, all works well.