DB/Reporting :: IDataReader And Connection Open?
Dec 28, 2010
In our application we use IDataReader which actually call function from one.dll where weExecureDataReader()
We have many calls in application and in some places For some reason I am getting error message "DataReader already open" but I am not sure where.What will happend if I simple close that conection in the that .dll? Am I going to make trouble to database because one datareader left opened? I assume closing connection will close reader too and gargage collector will manage that left opened datareader..
View 2 Replies
ADVERTISEMENT
Dec 16, 2011
SQL 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?
View 2 Replies
May 17, 2010
I have a connection string in my app.config:
Code:
connectionString="data source=.sql2008 ;Database=Database1; Integrated Security=FALSE; Persist Security Info=True;" />
How do I change to another database (one of many) without using multiple strings? Can I change while the connection is open?
Code:
Dim myConn As New SqlConnection(System.Configuration.ConfigurationManager.AppSettings("ConnectionString"))
View 3 Replies
Apr 17, 2008
If I use the CmdObj.ExecuteNonQuery() I got an error
I'm not having an open connectoin.
View 2 Replies
Aug 3, 2011
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]....
View 2 Replies
Nov 30, 2008
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]....
View 3 Replies
Dec 19, 2011
Try If functionmode = "ADD" Then
[Code]...
View 1 Replies
Jul 5, 2011
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]...
View 5 Replies
May 20, 2010
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.
View 6 Replies
Mar 11, 2010
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]....
View 7 Replies
Jun 12, 2011
Private Sub Button3_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button3.Click
exitwithout()
[code].....
View 1 Replies
Oct 21, 2009
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 Replies
Apr 11, 2008
i know this question was asked a couple of years ago by TheMinistered .. but i cannot find an answer, and i have exaclty the same problem (using both VB6 and VB.net 2003) :
When I attempt to connect to a remote SQL server via ADO it takes almost 20-30 seconds before Open returns. I don't know if it's something I'm doing wrong... here is my connection string/code:
Private Sub Class_Initialize()
Dim strConnectionString As String
Set m_objConnection = New Connection
[Code]......
View 5 Replies
Oct 27, 2011
[ASP .Net - Microsoft Visual Web Developer 2010]I've problem with this code:
[Code]...
Then, using that xReader.Read, store the value on the database onto that label based on the OrderNumber...
View 1 Replies
Sep 12, 2011
I have been struggling with the construction of an Access connection string. Here's the problem.My Visual Basic 2008 project is located in a disk partition on my hard drive that I have named S:. My Access MDB file is in the same location.When I deploy the application it obviously will not be in an S: drive on the user's machine. My concern is that if I construct the Connection String using the file designations on my computer as:
(Provider =Microsoft.Jet.OLEDB.4.0; Data Source =S:MyApplicationmydatabase.mdb; User Id =admin; Password =
The deployed application won't know where to look for the data file. I know there are some shortcuts that will allow me to construct the connection string, but I do not know either the designated names or where to find them.
View 1 Replies
Jul 23, 2008
I have created a very simple Visual Studio .net 2002 VB# program. It consists of form1 containing a DataGrid bound to an Access 2007 Database using OleDbConnection1, OleDbDataAdapter1 and DataSet11.The location address of the Database will change based on the user so, I need to make the connection string variable. Problem is inserting the following string variable "source=" & strFileLocation & ";" creates a fatal error
View 1 Replies
May 31, 2009
I have a little problem with checking if a sql connection is good.
Attached here i have a simple vb.net program that should check if the sql connection to the sql server is good. If i just run it once it works very well. But if i use it in a timer and check the connection to the sql server every 10sec it will only tell me that the connection is good (V=0).
I have tested the code with turning of the sql server service.
Dim connect As String = "Server=192.168.1.2;Database=Test;User ID=sa;Password=12345;Trusted_Connection=False"
Dim sqlconnection As New System.Data.SqlClient.SqlConnection(connect)
[Code].....
View 6 Replies
Jun 3, 2009
I get an error using the connection string (url...) to connect to my SQL CE saying that "Provider 'Microsoft.SqlServerCe. Client.3.5' is not registered in the local PC.".In my project I have a table connected (with the wizard) to the same database and it works fine, but when i try to connect with my own code it FAIL. [code]
View 1 Replies
Feb 17, 2009
I have a problem with the connection to my database. It's on a remote server, and this is my code:
[Code]....
View 7 Replies
May 14, 2010
I'm connecting a MS-SQL remotely with VB2008 Express.I defined two different methods - the first one is copied from my old VB6 application, which is working perfectly.In this application, the retrieved data is added to a listview control, not datagrid!
Code:
Dim myconn As ADODB.Connection
Dim MyRecSet As ADODB.Recordset
myconn = New ADODB.Connection
[code]....
The SQL query contain several table, thus I used a "*" instead for the table name- not sure this is correct?
Code:
da.Fill(ds,"*")
View 4 Replies
Aug 8, 2009
I am trying to use RAP (rabid application development). So I have created a database with a datagridview to show all information and textboxes to modify the informations. So far so good.
The problem is created when I try to use the search facility on the datagridview. The search is working but the problem is that the textboxes are not following the search criteria . I can configure this manual but I would like to know which is the easier way to configure the textboxes to show the value of my search criteria.
I also want to know how when I finished with the search criteria and empty the search the text boxes to make the connections back as they were before.
View 1 Replies
Sep 24, 2009
I have just written an application for myself and a few other users to use .rdp to connect to a number of servers, by clicking on the appropriate button. In the full version of the program I have two sets of connections one for when we are inside our vpn, which uses local ip addresses and DNS names; and the other which uses the external IP addresses and DNS names.This works quite well; if the user has stored credentials on their pc for the connection they connect straightaway; and if they don't the .rdp dialogue opens up with the server name/address filled in, ready for them to edit the rest of the required information.The problem for me is that this means I have to code 43 different Private Subs and then link the buttons; and I was hoping that instead of individually coding each connection, I could get the users to:Select by an option button whether the connection was internal or external
View 3 Replies
Aug 24, 2011
We have developed a VB 2008 app that uses SQL Server 2005 Express to store data collected by this app. This app has been designed to allow multiple connections to the one centralized database.
I have ran a few tests, and confirmed that if one computer running our app is accessing a database residing on a different computer,and the network connection between two computers has been severed, it would take approximately 3.5 minutes before I would get a connection timed out exception error from within my code.
I have deliberately set the ConnectTimeout property in the SQL connection string to be 15 seconds. But some how, SQL database engine still retries until approx. 3.5 minutes later.
My thinking is that I have a subroutine that would attempt to open a database once a minute.If the open attempt is not successful, and resulted in an exception, then I would popup a message to notify the user that the connection is not available.
Doing it this way, I have confirmed that it would take about 1.5 minutes for it to re-establish the connection, once the actual network connection has been restored.
To make the long story short, I would like to find a way to shorten the detection for a broken connection, and let the user know sooner, rather than locking up the app during the 3.5 minutes period has elapsed, and at the mercy of the SQL database engine to timeout. And why would it take 3.5 minutes to timeout the connection attempt when I had explicitly use 15 seconds in my connection string?
View 2 Replies
May 6, 2008
I am new to Visual basic and am using visual basic 2008 to write programs in, I have setup a database connection and the connection string is currently stored in the settings section of the project.I would like to have a menu item where when the user selects "test database connection" it will run the sub for testing if the database is established.
View 2 Replies
Sep 29, 2010
I have an SQl Connection: Con
con.close
after I close the connection I cannot copy the Sql Express Db because it is still in use but I have CLOSED the connection.
View 2 Replies
Feb 16, 2012
I have two cases to extract information from the IDataReader object
Case - 1 - Length, calculates ordinal and then parse string
public static string GetString(IDataReader rdr, string columnName)
{
int ordinal = rdr.GetOrdinal(columnName);
[Code]....
Which technique should be preferred and why and if any specific context ?
View 3 Replies
Oct 3, 2009
Connection between program and an remote SQL server. most of the hits were on VB6 and as you might see in the title I use VB.NET 2008, so let's begin:
[Code]...
View 6 Replies
Mar 3, 2008
I have been given the task of debugging someone else's program. It previously ran flawlessly on a 32-bit Windows XP system, but now we are steadily switching over to 64-bit systems and this program has "spit the bit" so to speak.
This is App.Config.xml
Code:
<configuration>
<appSettings>
[Code] .....
The problem is I don't know my alternatives are. System.Configuration.ConfigurationMananger.AppSettings doesn't work.
I've tracked the problem to the last line Con.Open().
Code:
Public Function get_quotes(ByVal strDBConnection As String) As DataSet
Dim con As SqlConnection = New SqlConnection(strDBConnection)
Dim strQuery As String = "SELECT qmpQuoteID FROM Quotes"
Dim da As New SqlDataAdapter(strQuery, con)
Dim dsQuotes As New DataSet("quotes")
Try
con.Open()
The error is "The ConnectionString property has not been initialized."
View 3 Replies
Mar 7, 2008
I need my program to connect to a database within my application i.e.What I have:
m_cnADONetConnection.ConnectionString = "Provider=Microsoft.jet.OLEDB.4.0;Data Source = C:Documents and SettingsmeroneyfMy DocumentsVisual Studio 2008ProjectsAsset Manager 2008inDebugDatabaseAssetManager.mdb"
What I need is: m_cnADONetConnection.ConnectionString = "Provider=Microsoft.jet.OLEDB.4.0;Data Source = DatabaseAssetManager.mdb"
I have used:System.Windows.Forms.Application.StartupPath & "ImagesSystemDefaultImage.bmp"
for loading of images within the default directory. but this returns the app path but also includes "System.Windows.Forms.Application.StartupPath" in the string?
View 3 Replies
Feb 26, 2009
Hoping for some advice, probably an easy question for most people on here but I'm a mere learner. Basically, what would generally be the reason for using a Data Set via adapter rather than just connecting to the database directly using an SQL connection?
View 2 Replies
