When it comes to database connections what is the difference between closing a connection & disposing a connection? I'm hoping to gain a more technical understanding of what happens when each is called & the effect on the database.
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i want to ask what is the difference between oledb connection and odbc connection. I have a case, my office used ncomputing then i have to developed an application using sqlserver 2000 and vb.net 2005, i used oledb connection. When i try to implement it in ncomputing, why user must has admin access level and dbo level in sql server, it seems trouble when all users are admin. But there's a rumor that when using odbc connection, we dont need to give admin access level for users.es.
View 1 Replies...this:
Dim Connection As MySqlConnection
and this:
Dim Connection As MySqlConnection()?
I have many Listviews in my Form and Im retrieving stored procedures to populates my Listviews. Is it necassary to close the connection to SQL Server once I have finished populating my Listviews?The angle which im coming from is that every 30 seconds or so I need to re-populate my Listviews with the latest cut of data from SQL Server therefor Im probably going to slow down my application if it has to connect to SQL Server every 30 seconds to get the latest cut of data... instead of keeping the connection to the SQL Server Stored Procedure live so that I can use some sort of method to refresh the data?
View 2 RepliesI'm connecting to an ftp server in my .net application. After I send the file and try to close the connection, I'm getting an error. I'm trying to send the Quit command to the FTP server but getting no reply. I'm not sure what I'm doing wrong. I call this method: [code] Do you think something is wrong with the code of could it be a problem with the ftp server?
View 2 RepliesIs it necessary to close the connection of a tcplistener or tcpclient after every message received, or is it possible to close it at a later time while it continues to receive data? Is there any major security issue with leaving it open and listening? I know trojans tend to open a listener and leave it open, will my program be detected as such? Its just a simple chat program....
View 1 RepliesI'm writing a Windows form application in VS 2008. In the application I need to move among several SQL express databases (.mdf). I'm using the following commands to change the connection:
Me.MyTableAdapter.Connection.Close()
Me. MyTableAdapter.Connection.ConnectionString = "NewString"
Me. MyTableAdapter.Connection.Open()
I can see the form is showing data from the 2nd database. However, When I tried copying the 1st database (for a Save as function I'd like to implement), I got a system error saying "Cannot copy MdfFile: It is being used by another person or program.". Actually, I found all the visited databases were "being used" untill I closed my application. How do I break the connection completely?
I get this error: You have an error in your SQL syntax; check the manual that corresponds to your MySQL server version for the right syntax to use near '*' at line 1 [Code]
View 14 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.
When connecting to a Sybase ASE database via ODBC using the code below, I'll occasionally get a '[IM006] [Microsoft][ODBC Driver Manager] Driver's SQLSetConnectAttr failed' error. this be caused by my code? I read here that I should be using the 'With' statement instead, but I don't understand how that would affect this.
[Code]...
Finally starting some coding in VB.Net, I notice over the years, that we can say (in VB6)
Code: Dim MyForm_Stock as NEW frmStock
in the same session, being able to open, say 3 Stock Forms at the same time and maintain details independently of each of the other forms. Also am I able to maintain separate Database connections and the same table being opened and updated independently of each other by each separate form. What is actually taking place in terms of memory being used by each process? My ultimate goal is to be able to have ONE Module with all the possible data Connection and Recordset Opening and closing options, which I have failed miserably to do in my VB6 experience. Data access is an obvious module based set of subroutines. Others could be Date routines eg, Week Number of the year, Days Diff, Days to, etc. [Code]
How 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"
Is 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 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.
I'm developing an app in vb.net (visual studio 2008). I have a Teradata back-end that will be supporting multiple users in a production environment. I need to use variables in the connection string as the user/pass will be changed every 3 months.
For the gist of the application:
In it's most basic form - I have a search form which works correctly - it pulls results into a listbox and the user then double clicks the list box which will then open a form that is bound via table adapter to the back-end table (Teradata). My connection string is fine everywhere in the application. My problem is using a modified connection string for the "fill" function of the table adapter once the form is opened.
I'm using the code below for the on-load event and keep getting an "invalid connection string" - again, the connection string works fine everywhere else in the app, and the variables etc... are working correctly.
Private Sub adaptertest_Load(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles MyBase.Load
Dim DBConnStr As String = "Provider=TDOLEDB;Data Source=TDDEV;Persist Security
[Code].....
I'm facing a problem after installation any software setup that has a database in access(mdb file) How to I transfer file path in our connection string.
View 3 RepliesI'm trying to insert a new records into database, one of those records is a "datetime"...when I type a wrong date, and try to insert those values into database, i get an error (about wrong typed date etc.)...ok, that's fine, things need to work that way. But here comes the problem, I correct the date, and then try to insert values again...here I get an error from the post title. And this doesn't work until I close that form and run it again...here's part of my code:
Dim cvLicence As New SQL
Try
cvLicence.upis("INSERT INTO blabla (itsnotimportant) VALUES ('something')")
MsgBox("everything's fine", MsgBoxStyle.Information)
[code]....
Private Sub Button3_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button3.Click
exitwithout()
[code].....
I tried to put the mso and msg objects into USING clauses - but they don't have idisposable methods so that doesn't work.
Dim mso As New Outlook.Application
Dim msg As Outlook.MailItem = Nothing
Dim body As String
[code]....
I am trying to connect DSN from my VB 2008 project. When i try using myoledb.connectionstring="DSN=myDNSname" I get the following error message An OLEDB provider was not specified in the connectionstring.
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