I am recently new to Visual Basic and am starting to learn some things i have managed to connect to the SQL Server and Insert rows to a table. But is there a way to be able to re-use an already existing connection ?My code below. I tried to create a class for the Connection object.
Imports System.Data.SqlClient
Imports System.Data.Sql
Public Class dbConnection
[code]....
I am working on uses the ThreadPool class and specifically the QueueUserWorkItem method to launch its background tasks. I am however having an issue related to SqlConnection timeouts. My error is this: "Timeout expired. The timeout period elapsed prior to obtaining a connection from the pool. This may have occurred because all pooled connections were in use and max pool size was reached."
This code is using all available ThreadPool threads because it is processing nearly 100,000 items, each on a threadpool thread, and updating an SQL database. So my question is this? Has anyone ran into a similar problem or could shed some light on a resolution to this issue? In testing, if I use the threadpool. setmaxthreads function and give it a value of 100 (to match the default Sql connection pooling count) then all runs just fine, but much to slow to process this much data.
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Let's say I have two forms: Form1 and Form2.In form1 I have two buttons. btn1Frm1 opens Form2 As New Form2. btn2Frm1 opens Form2 as New Form2
View 3 RepliesI m new to VB. I have created a form with Menustrip and want to reuse this menustrip in other forms. Could anyone plz tell me how to do it ?
View 8 RepliesI have a form in a C# project that I started and now I want to use that same form design in a new VB project I'm starting. Is there a way to "export" the form from C# and import it into my VB project? Obviously, I don't want the C# code behind the form, just the design.
View 1 RepliesDim conn As MySqlConnection Reuse a variable from another event?
View 3 RepliesI wanted to know if it is possible to reuse a class I created in one application in another application. Basically I created a test program and once I got all the components working I created a class for it and well I want to use the class in another program, how can I do this?
View 2 Replies(using vb 2008 I am learning the workings of Custom Events. I think they might solve the problem of being unable to declare nonserialized events in vb2008. However, do custom events follow any sort of inheritance pattern like classes
View 4 RepliesI designed a form - please see a picture My first intend was to "link" each button on the menu [Employee Management, Contact Information,...] to different forms by coping this form and then designing the contents of the form using many repeated following code
Dim oForm2 As New Form2()
oForm2.Show()
Me.Hide()
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I have this code
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When I add an image to the imagelist, the con shows up. That's fine Let's say that I added 4 images (four items to the listview) then remove one item from the listview. From there, the next item I add will adopt the previous image added. How can I keep this from happening?
How can I tell something to use a code without completely adding it in that sub again? I have some code that will be used alot within my program. I could write a DLL, but I don't know how to use those!
Here is my code:
Dim str1 As String = System.IO.File.ReadAllText(Me.OpenFileDialog1.FileName)
Dim s2 As String = str1.Replace(".[1gs5]", "a")
s2 = s2.Replace(".[u775]", "b")
s2 = s2.Replace(".[fsef]", "c")
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It is possible to buil un user control with a menu strip with this options (add record, delete, update) and reuse it in difrent forms?But, for example in form name "Cars" the option Delete must delete the cars currente record, but if im in form Buses, the same button wiil delete the bus record.
View 5 RepliesWhats the easiest way to reuse the content of my project ... e.g. Forms,UserControls. that will include all the required files ... e.g. resources,pictures
View 2 RepliesWhen I made the code in the sub generic and passed in the values the timer needed (hour, min, timername) from a start button it seems not to matter which start button is pressed as the labels output the information for the last button pressed.
View 1 RepliesOne of the VBF member was asking how to add a close button on the BindingNavigator control once and reuse it on all other forms, so I try to create a custom bindingnavigator class that inherits the BindingNavigator class.Below is the inherited class:
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The thing that I can't figure out is that it looks OK in design mode, but at run time, the custom binding navigator shows 2 "Close" buttons. Only one of them will close the form when clicked, the other one doesn't function. See the attached image.
In my project i added a User Control so that i can reuse in different Windows forms.I designed and coded the UserControl1 according to my need and now i want to use it in Form2 but i cant understand how to do it?
View 2 RepliesI defined the following extension of the Date? data type
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But when I moved my compiler definition to a separate DLL, I the ToObject method was no longer available from my project even though I had referenced the Class project which now contained the extension. Is this a limitation of the Compiler Extensions? HOw do you get reusability out of them?
I have an application that queries DHCP and pulls scope/subnet information. There are roughly 8k scopes on our network to query so reporting this data takes a little bit of time. I currently have this running on it's own thread and reporting to a progress bar so the applications doesn't seem inactive.
The DHCP api functions can report a total, a max read and a resume argument. This means that I can, in theory start 4 threads and have each thread read through 2k subnets, so it will only take 1/4 of the time to read all this data. Would I need to create four separate background worker handlers, do_works, runworkcomplete, report progress etc.?
I am trying to update some code. I have a vb file that begins with this...
Imports System.Data.SqlClient
Imports System.Data.Sql
Imports System.Data.SqlTypes
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...and it accepts it. Why do I need to explicitly write out System.Data.SqlClient every time I use an object from that class???
i would like to know if there's something wrong in this asp.net code:
mydatareader = mycmd.executeReader()
if myDataReader.HasRow then
// Do something
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I am confused about something and I hope someone here can give me an answer
View 3 RepliesI am learning ADO.NET But it very hard for me... I dont understand why have got this compiler error:"Declaration expected" for the connection.Open().[code]
View 1 RepliesWhat would happen if you call Close() on a SqlConnection object before you call Close() on a SqlDataReader using that connection?
Actually, what I really want to know is whether or not the order in which you Close them matters. Does calling SqlConnection.Close() completely close the connection, or will it remain open if you do not call Close() on a SqlDataReader using that connection?
I don't think I really understand how connection closing works.
I keep getting the following exception when I do:
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I'm having a problem with my global connection function. It used to be a readonly property but I changed it to a function because the code anaylsis engine was complaining about my property raising exceptions. The function is designed to take account of our offsite database mirroring system, so if it can't create a connection to the principal server it switches the connection string to the mirror server. This works fine in another project we have:
Public Shared Function Connection() As SqlConnection
If String.IsNullOrEmpty(ActiveConnectionString) = True Then
Throw New PropertyNotSetException("Cannot call Connection() before
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I have a SqlConnection global variable in my proyect that it is always open (I wouldn't like to start a discussion about keep the connection open all the time or close it everytime a transaccion is executed).
This variable is sent to every class I need to execute a function or method. Instead of checking the connection in every single operation, is there any way to monitor the connection state in a centralized way ?
I'm trying to add transaction support to our database object.This object is a Remoting object. (this to ensure that on the Windows Client, no database connection is required.)Now I want to add support for transactions;Basically, a client will need to use it like this;
BeginTransaction
ExecuteNonQuery("insert...")
ExecuteNonQuery("insert...")
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[code]in this code, do the objects con and cmd get disposed because the return statement is placed before the end using statement.
View 1 RepliesImports System.Data.Sql
Imports System.Data.SqlClient
Imports System.Configuration
Module Module1
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this is my connection string on my pc how can i make this as a dynamic connectionstring so i cant remove the db and get a new connectionstring?
I asked a question earlier where I was told a simple way to "bind data to objects" is to just run a SqlConnection(connectionString). The response also included a comment saying I could get fancy with L2S and Entity Frameworks, so I looked deeper into those. It seems all you have to do with the DataContext object is point to the database. Why would SqlConnection be a benefit? What is the difference (or pros/cons) of using either one of these? Is one more "standard"? Is one more modern?
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