I'm trying to a open a connection to a local database and no matter what I try it just won't work (I'm pretty new to SQL Server and VB for that matter) I tried using 'sqlconnection' with different connection strings but none of them worked or gave me any useful error messages so I tried using 'OleDBConnection' instead, this hasn't worked either and it gives me this error instead:"A first chance exception of type 'System.NullReferenceException' occurred in MyProgram.exe"
Here is the code I am currently trying:
Private Sub MemDetailsSearch_Load(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles MyBase.Load
ConnectionString = ("Provider = Microsoft.Jet.OLEDB.4.0;" & "Data Source = Database.sdf")
DataConnect = New OleDbConnection(ConnectionString)
I've been looking over a bunch of code snippets and I'm just not understanding what is going on there.anding the connection, reading/manipulation, and closing pI keep reading all about these DataAdapters, Ole and Sql and Sqlce and I don't know which to use or whatever.I made a database in VB.NET 2010 that came out as database.sdf and I selected the Local Database option (I assume this is relevant?). I then populated the database with a row of data with column titles and a primary key. The table contains many different columns, but for test purposes, the following is relevant:
DB Name: db_test Table Name: Locations Primary Key Column Header: CITY
I have attached Database to my vb.net application. Client has sql server 2008 express installed.I built my application and gave to him. he is encountering errors.
i am getting Cannot Open Database for requested Login. Login Failed. i am using SQL 2008 server Developer edition. And using Windows Authentication mode.
I have a .mdf file that I open through an Open Dialog Box and use in a ConnectionStringBuilder (where I have the user instance set to True). Later, in one of my button clicks, I try to open the connection (connection.Open()). It then gives me an error as follows: "Generating user instances in SQL Server is disabled. Use sp_configure 'user instances enabled' to generate user instances."
Here is my code:
Option Strict On Imports System.Data.SqlClient Public Class frmMain
I am currently working on a login page using vb.net. I would like to know how to make connection to an access database and verify that the user logged in is a valid user
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.
I am developing an application that is using a Jet database (Access 2007). The database is local to the project (e.g., on the same drive and in the project directory). Any time I attempt to access the database (to create another DataSet, etc., via designer, etc.), I get the ubiquitous "Failed to open a connection to the database" with: No error message available, result code: E_UNEXPECTED(0x8000FFFF). Opening the Database Explorer and attempting to attach to the database results in the above as well. There are no apparent locks on the file, etc., and I'm the sole developer for this.
I installed SQLExpress 2008 on my computer this afternoon and have been trying to create a new database and open a connection to it. I found this code online and tried it:
Dim conStr As String = "Server=MSSMLBIZ;Database=;Trusted_Connection = yes"
I keeping getting an error.Seems to be the connection string.Error happens at connection.Open()
Error Message:Cannot open database "C:UsersJEREDocumentsVisual Studio 2008ProjectsBaseball2009Baseball2009DatabaseBaseball2009.sd" requested by the login. The login failed. Login failed for user 'JERE-PCJERE'.
Imports System.Data.SqlClient Public Class Field Private Sub Field_Load(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles MyBase.Load[code]..........
The 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.
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 =
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)
I have a query that is working fine on my local but when placed on the server it comes back with this error,
Server Error in 'Page' Application.
ERROR [IM002] [Microsoft][ODBC Driver Manager] Data source name not found and no default driver specified
Description: An unhandled exception occurred during the execution of the current web request. Please review the stack trace for more information about the error and where it originated in the code.
Exception Details: System.Data.Odbc.OdbcException: ERROR [IM002] [Microsoft][ODBC Driver Manager] Data source name not found and no default driver specified
Source Error: An unhandled exception was generated during the execution of the current web request. Information regarding the origin and location of the exception can be identified using the exception stack trace below. [Code]
In VB.Net, I'm trying to connect to WMI on my local computer with different credentials (the user won't have admin rights) and I get this exception : « User credentials cannot be used for local connections » Here's the code :