Way To Establish A Connection For Use With An ADO.NET Command Object?
Sep 11, 2009
I'm designing a web service in ASP.NET and VS2008, and am using typed datasets for retrieving table data. These work well and establish their own connections through their associated TableAdapter objects. Edit: I'm using VB, BTW!I am now attempting to run a custom SQL string using a DataAdapter and a Command object, however I need to reference a Connection object in order for the Command to work. What is the best way to handle this?hould I:a) Create a global connection object using Global.asax, retrieving the connection string from web.config? (I've been trying that one already, with not much success)b) Create a class-level connection object using the InitialiseComponent method, also retrieving the ConnectionString from web.config?c) Retrieve a Connection from one of the TableAdapters that I've already created in my typed DataSets?d) Something else I haven't thought of yet?
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.
This will happen at random, and I can always just catch the error and re-establish connection to the server, but I am confused as to why. When doing lots of inserting into the sql server, I only establish one connection that is public, instead of many little connections. I had my doubts on a public sql connection, but it's been running great, and I've seen no problems until this morning. Again, this random moment I hit an error that stated, sql connection state is broken. Is it bad practice to just accept this error, and when it happens, re-establish the connection?
im 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'm using Visual Studio 2005 and SQL Server 2000 for my vb.net desktop application..I'm having a SQL Server exception saying that "connection can't be established to the server.hen connecting to SQL Server 2005 this failure may be caused by the fact that under the default settings SQL Server does not allow remote connections. Also showing
I just can't seem to establish a connection between my two P2P applications over the internet(LAN works perfectly fine).
I have tried the following. - Disabling Firewall - Changing Port
The only way I can establish a connection is if I'm connecting to the same computer using the universal IP or the local. Does anyone have a fix for this? Oh and here is the error that I receive when trying to connect over the internet:
System.Net.Sockets.SocketException: No connection could be made because the target machine actively refused it 255.255.255.255:8787 at System.Net.Sockets.TcpClient..ctor(String hostname, Int32 port) at P2P_Client.Form1.Msgtxt_KeyDown(Object sender, KeyEventArgs e) in C:\Users\Administrator\Documents\Visual Studio 2008\VB Projects\P2P-Client\P2P-Client\Form1.vb:line 32
i use vb 2008 office 2007 , it's a powerpoint add-in application. I need to use a window form as a bluetooth interface.the working procedure is like that when i click the Enum button, it will help me to search for available bluetooth devices.but now i have an error, it shows "WCL ERROR: Specified transfer is not available"
I have being trying without success to create a program that can establish a SSH connection with [URL] on a changeable post with a set username and password. The program when done will configure IE proxy settings and establish a SSH connection to [URL] to allow the user to browse the internet without restrictions.
I want to start a new project on PC and Mobile Phone. But i'm still have so many question about the communication between PC and Mobile.
My project List: 1) My idea is establish a connection between PC and Mobile through IP address in first, but my question is 'How to do it' ? izit same like PC to PC by using Winsock open a port to access? i'm using VB.Net 2005 for PC and Net60 for mobile.
2)My mobile phone Nokia 6220 Symbian OS is support GPRS/3G. Since the GPRS/3G can connect to the internet, izit means mobile itself have a IP address and service provider in order to surf the web? So, can i connect my mobile phone to PC through this gateway?
I have a project in Visual Studio 2008 and there is a working data connection to a MySQL database. In other words, I can query the db directly from Visual Studio and it will display the results.
I've tried a couple of approaches that I found online for writing a connection string and accessing the db, but no luck yet.
All I'm trying to do is code a button to query the db and then reset the text property of a label/textbox to display the results based upon another label/textbox value.
The pseudo-code I am imagining is something like this:
Private Sub query_submit_button_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles query_submit_button.Click result_textbox.Text = SELECT field FROM table WHERE otherfield = key_textbox.Text End Sub
I didn't see any related questions posted on SO - forgive me if I missed one that already exists and this is a dupe.
I am confused; I am using VB2010, IBM.iSeries.DB2 on an as400 V5R4. I am trying to establish an OLEDB connection, and return the values from the selected table to a DataGridView. I had one of the admin's make me file named GARBAGE, in the Rprtaccess catalog. In the past, I have been able to connect via access and an ODBC connection. My project is too big for access, and the SQL middleware we have is clunky and not user friendly. This is a program that will generate the SQL statements, specifically the WHERE: clause and populate the datagrid with the selected criteria. In essence I am making a user friendly striped down program, that has variables that are manipulated by the end user, and the rest, referenced tables and libraries are coded.
Imports System.Data.OleDb Imports System.Exception Public Class Form11
Any ideas on how I handle the following error thrown in the SqlDataAdapter.Fill as a result of the BeginTrans in the callee?
System.InvalidOperationException = {"ExecuteReader requires the command to have a transaction when the connection assigned to the command is in a pending local transaction.The Transaction property of the command has not been initialized."}
SQL connection - I planned to create one sql connection object inside my own singleton class (say connectionmanager with Reference counting for 'SQL connection object' which is a member of the class) and open/close the connection whenever needed. As I like to give high importance for performance. And my application is a desktop based application accessing a remote database server (SQL server 2008), and will use only one connection string, 50 concurrent desktop users may access db server. Please advice.
As like many articles say if the answer is "Connection pooling is taken care by ado.net" - Does that mean that scope of connection pool is entire life of Application instance? Or is it in the scope of SQLConnection object?
I am getting errors when I try to use this adodb.connection and command in my code. The error I am getting is saying that the connection and command are not defined. I read online that depending on your version of vb that you might use the "OLE" connection instead of ADODB.
i was using a pocketpc phone and i want to have a program it with a database.i am not familiar w/ the database of vs 2k8 because it was using a dataset i i dnt know how to connect the database of that...
i connect the Datagridview by using command connection not coding. now i have "table3tableadabter", "table3bindingsource" and "database3dataset" below the form ? the search string " "Select * from tabel3 Where test2 like '" & Me.TextBox1.Text & "%';"" how i can do serch and the result will be shown in datagridview.
I have been working on this all day and still haven't had any luck at getting it to work. I am using the SqlDataReader Object to retrieve data. I am using the code below to send a value to the stored procedure.The problem is that the value is sent enclosed in quotes so I dont get any data back. I have tried using .text.replace("""","")
I have 2 panels and what to run a command when they are a minimum of 30 pixels away from each other. Ive tried pnl1.intersectwith(pnl.bounds - 30) but doesnt work out
I'm helping a colleague develop a "catch all" type error handler for some controls his application. What he wants to do is pass the object that has the error, and the type of that object, such a TextBox or ComboBox, and then call the DirectCast method within his handler to properly address the Text attribute within it. In general, the method is looking like this:
Protected Sub SpecialErrorHandler(ByVal TargetControl As Object, ByVal ControlType As String) MessageBox.Show("Bad Juice: " & DirectCast(TargetControl, ControlType(ObjType)).Text) End Sub
So far any attempts to do a type conversion within the DirectCast method (since it is expecting an object in the general signature) or to even pass in the a Type object properly set is not working.
Any ideas here, or is this one of those "Casting doesn't work that way." type scenarios?
i wanna know for example if you have a few functions that actually creates a new sqlcommand in it and disposes them after use or is it better to have an sqlcommand at the main function and pass the sqlcommand in byref . and after using it. Juz clear the commandtext and the parameters.[code]
I'm trying to delete a record from an access database using the command object in vb.net 2010 express but can't seem to get anywhere.If I run the code below, I get no errors but nothing happens. The connection opens fine but the db does not update.the table has only two columns.The variable strCrit is so that I can build the sql string with exclamation marks, When I debug.print the sqlupdate string it seems to read fine.the routine is called from a form with a button.
Dim sqlupdate As String Dim strcrit As String strcrit = """"[code].......
