Should I open a connection to MySQL at the load of my application and close it when you exit or should I open and close the connection only when I need to run queries?
View 1 Repliesi 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 =
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In my program, I have a timer with a inteval set to 1000ms. The timer is executing a MySQL-command, and right now I'm opening and closing the connection each time.
View 5 RepliesSQL connections confuse me sometimes In almost every SQL related code on the internet the routine is like this;
* Open connection
* Execute SQL command
* Close connection
Is it good practice to just open a connection when the application starts and use that connection until the application closes?I know that sequential connections are required when processing more queries, but what if I need to poll a certain Table every x seconds? Isn't is better to keep that single connection open for as long as the application is running (and re-open when a failure occurs) instead of opening a new connection every x seconds?
I want to know what is the right way to close my Database connection while its open.
This is how i open my connection.[code..]
In the first form I will load Tabels in the secound I want to open the DB Connection. I wrote a Class which enables me to open and close the connection
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I am developing an application with VB using the MySQL Connector Net [URL]. Now each time I go to load data in to a datagridview or in to text boxes on a form, I have to provide something along the lines of:
Private Sub btnSave_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles btnSave.Click
'Create connection to MySQL Database
Dim conn As New MySqlConnection
Dim myCommand As New MySqlCommand
conn.ConnectionString = MySQLGlobal
[Code] .....
I think it would be better to leave the connection open to the MySQL database while the application is in use. That way I can just continue to execute queries of inserting and updating, without having the delay of the application having to reconnect. Is there a way where I can create some sort of background task in the application that monitors every few seconds that the connection is still active, and if not it tries to reconnect until its reconnected? I am trying to have it so that then I can code it to just do queries, and when the connection breaks - it disables the form until it is reconnected.
I am building a program for a small office and I have a little problem with the code so I thought it's better to post a topic before continiue.. I have search into google and a lot of forums about database connectivity and my problem is simillar to other but a lot of things differs.The error that I get is on executeNoQuery() and it's called {"Connection must be valid and open."} Well a lot of things may related to about that.At least now from my re-search I covered all the filds of the problem and still not fixed. So please check my code for (Add new customer) button and let me know where I have mess up.
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When using SQL connections in my program, will I have to open and close the connection and the data reader each time I want to access the database ?
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I have an application that I made in VB.NET. I put it in the server on my office and every other user access it via network connection. I only mapped the drive onto their computer and then I cope the shortcut to the application. can I close all the application that is running with a single code? I sometime need to close all the application first before I can do anything with the application (for example, modifying the report etc.). My current method is still the manual one, which is calling everyone to close their application or running all over the place closing the application myself.
View 1 RepliesI am building a database application using MYSQL as the backend. The MYSQL instance will be installed remotely on a share host. I have access to SSL certificates. I'm obviously not looking for any code but, conceptually, how do I go about securing the connection using SSL between my application and the remote MYSQL database?
View 2 RepliesI would like to close my appliaction and then open it based on a condition.Lets say I have a Lab1.EXE file, I want to close if the flag = True and then reopen it.
If ClFlag = True then
Application.Exit
---Then
RUN LAB1.EXE
Endif
I am developing a chat application using online connection to a mysql databbase. But i am facing a problem. After 10 minutes, MySQL closes all the chat connections because of the 600 seconds timeout (has been set by the host service i am using). I don't understand why is that happening cause every piece of my code which needs data from the database opens and closes the connection (i mean that it dosn't maintain the connection after the query's execution). If i .close() and .dispose() the connection, it still appears in mysql at sleep mode (it terminates only if i exit the program).
Dim MySQLCon as New MySQLConnection
Dim MySQLCom as New MySQLCom
Dim counter as Short
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I'm trying to make a login from in vb2010 as a windows application but I keep getting a error message saying "Connection must be valid and open"My code for the sign in button is:
Private Sub Button1_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles cmdok.Click
' Adminstration login
' Add code here for secure admin
[code]....
I'm using vb2008 How can make the application work(load) when I open my computer?
View 4 RepliesIn a program I'm working on, I want a "Loading..." dialog to close when it can't log in to a site using the username and password provided by the user. Basically, I have the code set up right because the function it is supposed to carry out when that occurs does work, but for some reason it ends up in some really weird stuff happening. In the Loading form, I have it set to do "Form1.Show()" and then "Me.Close()", assuming it would simply show the login form and then close the Loading form. However, when this happens, the Loading form closes, and then for only an instant Form1 shows, and then the Loading form shows and Form1 closes. This happens forever until I stop the debugging, and I can't seem to figure out why. Am I using the wrong method? What exactly does Me.Close() do anyways? All I want to do is close the form and open another
View 5 RepliesThe fact is I'm making an application, which users can install by using a Setup file...once installed the data in the database can be updated by a centralized server. To do this, they can insert a DVD/CD-ROM and export the necessary data towards it. I need to do it that way, because some of the users who really need this data will be using stand alone computers.The application gets it's data from a mdb-file and the connection remains open as long a person works with the application (maybe not the best way to do, but I know :-) )...when the user uses the application, he can perform an export...this exports the .ini-file and pictures (which works fine), but he also needs to export the mdb behind the application...I already tried connection.close() before and connection.open() after the System.IO.File.Copy...but that doesn't seems to work.
View 2 Repliesi 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]....
Try If functionmode = "ADD" Then
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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
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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 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].....
It seems like whenever i click my close button the application will close but the debugger is still in active.How to exit this debugger? :)
View 2 RepliesWhat i have going on, is i have a MySQL connector as a resource on my application, and im basically trying to connect to my MySQL server, to either a) register a new account, or b) check that the account exists and they are premium, and login, Now what i have run into problems with is: My MySQL Database Name has a _ in it which VB is not allowing for some strange reason.
The code i am using is below
Imports MySql.Data.MySqlClient
Public Class Form1
Function UpdateRecord(ByVal query As String) As Integer
[CODE]...
How i can allow the _ into the application, because the only databases that don't have a _ in the user or dbname are a) Paid ones which i DO NOT have the money for or self hosted ones, i cannot leave my computer on 24/7
sometimes, when I use Form.close() when debugging my program, although the form is closed, the application is still running. I noticed this behaviour when using the msgbox function.
View 3 Replieshow to use windows calculator in vb.net 2008?
use System.Diagnostic.Process.Start(calc)
its working but i want when application close it also close this calculator how?
I am trying to login with this code which is working alright but the problem is anytime i make a mistake in trying to login with a wrong password is gives me an exception that the connection was not close but it is open i have try to fix it but to no avail. [code]
View 4 RepliesAs I watch in MySql Admin connections to server, I see the connection get made but it never disconnects. Is this different from VB6?
Private Sub WorkerThread1_EnterEvent(ByVal sender As System.Object, ByVal e As AxVBVoiceLib._WorkerThreadEvents_EnterEvent) Handles WorkerThread1.EnterEvent
Dim conn As ADODB.Connection
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I used code below to close connection, is it right?
Try
myConn.Open()
mySQLCommand.ExecuteNonQuery()
Catch ex As Exception
'code to display error message
Finally
[Code]...