I'm testing database programming in vb.NET 2008 at the moment and try to find a way to use a database connection in different forms, so e.g. I put the the database-connection-component into one of the forms. I know, I could access it by e.g. form1.databaseconnection.xxx, but is this the best way or can I "put" the connection into something more abstract which all forms know about?
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I have a VB Solution with a dozen forms trying to implement invoice system.My main form (Say Form1) only has a design to create , Edit or Delete Customers.My form 2 will be opened if Create button is clicked. In my form 2, I have textboxes where user can enter Customer details and click on SAVE. My doubt is here....On clicking this SAVE button in Form 2, I want a INSERT command to happen on the MSAccess's Database table called Customer (which I have already created... this table does not have any records as of now). In my form 1, I added a MSAccess Database with a Connection String. In my Form1's code I have code like this[code]...I got this piece of code from this link [1]: vb.net - sharing mdb access connection among multiple forms/Now, I do not know what more code does this require to INSERT records from my text box into the Customer table's fields.
View 1 RepliesI'm starting to put in a database into my application, however I'm drawing a blank on how to share a database connection among the dozen or so different forms in my MDI application. I'm assuming this has to do with interfaces or something but I can't find any relevant examples anywhere. Can someone help me out? Ideally what I'd like is when the app is loaded up there is a call to a function in the forms loading area which establishes a single connection to the mdb, that I can then call via any form so I don't always have to open/close connections everytime I need to update the db?
Here's a basic example of the mdb database access code I've got working:
Dim dt As DataTable = New DataTable()
Dim OleDbTran As OleDbTransaction = Nothing
Using connJET As OleDbConnection = New OleDbConnection("connection string here...")
[code]....
is there a function that will allow coders to connect to multiple database? by just changing the connection string and not the variable declaration ...example:connecting to access is something like this
Dim Con As New System.Data.OleDb.OleDbConnection(ConString)
for sql is something like this
Dim Con As New System.Data.SqlClient.SqlConnection(ConString)
is it possible? acctually in vb 6.0 it is possible ...
I have a problem with connecting to a server which is another machine. When I try connecting to my machine with the following code, it works fine:
'connString = "Data Source = .sqlexpress;" & _
'"Initial Catalog = one;" & _
'"Integrated Security = SSPI"
[code]....
I am trying to build a user control that will do exactly what the SQL 2005 Connect to Server interface do, eventually create a connection string and store in a app.config file. It should allow user to select server type, server name, authentication, user name and password. It should also automatically load available servers and domain login by default.
View 11 RepliesIs 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.
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 am using access database for my program. now i have connected to the database in MDI form of main exe, and ir also works, user can log in, it gets verified etc etc etc. now here is the problem, when i load a form from dll and try to use any sql query on that form, i get message, "database connection is not opened". so what i did was, i added the connect() (a function i designed to connect to database) in the load part of the dll's form, it made the trick, query's started to run, everything went fine, and when i reload the form i.e after closing the form, i load it again from MDI form, i get error, connection already open..
[Code]....
I have the requirement to create an application that has multiple front ends developed using Windows Forms, WPF, ASP and Compact Framework Mobile Forms.I would like to be able to create a series of obejct representing the business logic and have this logic accessible from the various front ends available. My first thought was to use remoting as I'd like to be able to pass the business objects back and forth between client and server but the compact framework doesn't support remoting and also transferring a full framework business object to a compact framework business object doesn't seem possible.My next thought was to use web services but again the passing of business objects seems to be very hard to accomplish. Without doing this I would have to create individual web methods for each business operation.
Finally my next option is to use sockets and write the whole client/server logic within some classes and expose them to the UI/Business layer. My only problem with this is it is not scaleable should the number of clients increase dramatically whereas using remoting or web services I can host the solution via ASP.Net.Does anybody have an ideas on the best way forward for this or even have any input on how they would write an application that required a windows form, wpf, asp website and mobile device GUI all of which want to use the same business logic?
I have googled high and low to find an answer to this but I must be searching wrong.I have an application which has a listview displaying some items that are stored in a SQL Compact database. I am using a second form to add new items to this list directly into the database.When the second form closes I want to call the sub in my first form to refresh the list from the database.
How can I get it to fire the form1 sub routine on the close event of form2
i was doing a fair amount of programming many years ago, like 10 it feels like, so I'm sorely not up to date on how my newly downloaded Visual Basic Express expects me to communicate with it.I am writing a program that pulls a cell from a database after the user has gone through several forms to determine which cells they want. When I write it like that, it doesn't sound very efficient, but I've designed it this way for usability.Here's where I have a problem: Should I store the path the user takes in a string, an array, what?
Here's an example:Someone wants baseball stats and trivia. They run my program, main form pops up, they select National League button, the NL Form pops up. Now the way my program is set up right now, is there are two ListBoxes on the form, one is populated, and as the user selects a Team from ListBox1, it jumps to ListBox2. Once they've selected all the teams they want info for, they click a button Next.
What I now need the program to do is show the next form "Team: name" once for each team, and insert the name of the team on the form in the appropriate label which I'll have blank. This form will also do the Listbox thing except the first listbox will populated with Topics like HR Stats, Pitching Stats, Coach History, etc.
I am using MySql 5.0. I using Mupliple datareader in same connection i get error message. Is possible to use multiple Datareader in same connection?
I using Mysql Connection is
MySqlConn.ConnectionString = "SERVER=" & gServerName & ";DATABASE=" & DBname & ";user=" & gUserName & ";password=" & gPassword & ";MultipleActiveResultSets=True"
MySqlConn.Open()
I have a vb.net web app and I am passing a SQL connection and a transaction to a method which writes a single record to the database.
I would like to start and commit a transaction for each record that is written but using the same sql connection until the loop is done.
One method I saw was utilizing a using statement but it didn't work for me.it runs the first time and gives an error on the second that the transaction has already been commited
Using sqlConnection = New SqlConnection(ConfigurationManager.ConnectionStrings("ConnectionString").ConnectionString)
[Code]....
I am using datareader to retrieve data. I want to use multiple datareader at a time with same connections. WHen i used it, it gives an error as connection should be closed before using it next time.
View 23 RepliesI'm using a OleDB connection to a access database. I'm entering a row into the database to set some user preferences. What i need to get is get back the row ID of the row I just entered. I'm more familiar with PHP and with PHP I use use this entry
[Code]...
Launch a dialogue window from the main form, and then another dialogue window from that dialogue window. If you close the second dialogue window and call dispose the main form vanishes under any other open windows. This doesn't happen by closing a dialogue window normally, but I am attempting (rightly or wrongly) to stop memory useage creeping up by disposing of it.
So, the question is - what method can be employed to maintain the position of the windows?
I have two forms frmMain and frmNew, and one module modMain. In modMain I hold public variables which are needed for application. My question is how to open and close those two forms when needed? I ask this because if i set frmMain as startup form, then when closed, application will end, and one of those two forms will always be displayed. Also if I set frmNew as startup form, then when I close this form, application will also end. Is there a way to do this from module or something so my application won't end after closing and opening any of those two forms?
View 2 RepliesVB.NET newbie here... I have an vb.net windows application set up. It has multiple forms, about 6 in all. There's a main menu form, and then 5 other forms to collect data. The user will collect data on each form and bounce back and forth between forms. How do I get the forms to retain the data that has been entered into the text boxes and/or other controls on the forms? For example, they might fill out a few textboxes on a form, but then need to go to a different form and fill something out... and then back to the previous form. Right now, when they come back to the form, all the data previously entered in to the text boxes is gone.
View 1 RepliesI am trying to write code with multiple forms. The first screen is splash screen then is supposed to close and have a calculations screen. In the timer of the splash screen I wrote the following code
Option Explicit On
Option Strict On
Public Class uiHinsbrookSplashScreen
[code]....
This opens the second screen, but when I Hit Exit on the Second Screen The first screen is still open. What do I need to do next?
I have a vb.net web application and when a particular function runs , i get data timeouts in the rest of the application..(ie..row not found errors or column does not belong to table but it does) The function is adding multiple rows in multiple tables in the database and is running in a for loop. It seems to be all SQL related but I am not seeing anything in the error logs in SQL or in the application Right now I am assuming it is memory related where to start note..the for loop will be replaced with a bulk insert but right now I jest need to resolve the issue of the timeouts
View 1 RepliesAm developing a server - client application using the system.net class , that will have more than 5000 simultenous client connection.what is the best way to manage multiple client connection like this?
View 3 RepliesI am creating an VB 2008 application which uses 2 connections strings in according in which computer is running (my test machine, and the production server). How should i manage the connection string in order not to change manually the connections string which are many inside the code??
I have read that you can read them from an external line, or if you put both connection strings in an external file, according in which machine the program is running can actually the correct string?
I want to make a simultaneous connection to multiple servers with threads, only to create a single connection.
Imports System.IO
Imports System.Net.Sockets
Imports System.Text
[Code].....
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 trying to copy a table in a database into another database on another connection in VB.NET, using OleDb. If they were on the same connection I would just use SELECT INTO, but they are not. I have two different OleDbConnection and cannot see an easy way to do this.
Right now I am attempting to just copy the database into a DataTable using an OleDbDataAdapter, and then loop through the DataTable and insert every record into the target database one at a time. This obviously takes a ton of time for the large DB I could potentially be dealing with, and I have to deal with escaping strings, null values, etc.
edit - just to make this more clear: I have two OleDbConnection objects, one is linked directly to a local .mdb file on my computer (JET). The other is linked to a database on our servers (SQLOLEDB). I am wanting to do this:
"SELECT * FROM fromDB INTO toDB"
But I can't because fromDB and toDB are on different connections, and the OleDbCommand object is only attached to one. The only way I can see how to do this is to connect to fromDB, copy it into a DataTable, connect to toDB, and copy all of the data in the DataTable row by row into toDB. I was wondering if there is an easier way to do this.
I need more then 1 (MS-SQL) connection string/configuration, depending on the current running configuration (Development, Production, offline etc.)How could I declare these connection strings in advance (Proj.Settings) and tell the application which one to use without the need to compile the program.Using a command-line argument is an option but still unconvenient.I know .NET/ASP has an 'outside' non-comipied config file used by the application which you can modify.
View 3 RepliesIn 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
[Code]...
I have the below mentioned code in a seperate class file for establishing connection and carry out DB transactions. I have an issue where multiple connections being opened which sometime exceed the connection pool. When I stepped through the code I found that there are codes which call ConnectDB() in a loop without calling DisconnectDB(). But I expected that the condition OraConn.State = ConnectionState.Closed should handle the situation. Somehow the condition is always satisfied hence openning another set of connection. Can you suggest where am I going wrong and also what best practice can be adopted here?
[Code]...
The connection is again opened in function updData(). While I understand that it has to be closed correctly but keeping tab on every developer is not possible. Hence I want to control it directly from the connection class by using the same connection but the condition If OraConn.State = ConnectionState.
UPDATE I have put the code in UpdateDB under a Using block and removed call to ConnectDB and DisconnectDB from function like InsertData(...). It seems that the issue has been resolved. But I would like to know in case of exception will the connection remain open? and also OraConn is a public variable defined outside Using block so will it be disposed of by the GC?
[Code]...
I'm still learning vb.net, so I'm not terribly familiar with all the terminology, otherwise I would have searched a little harder before posting. I'm working on a program where the user can add various forms to a MDI parent.I would like each of the child forms to be part of the same array, all of the child forms will be of various types.Some forms may display a textbox, some forms may contain a graph, some forms may contain an image, etc.[code]
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