Database Connection Dll - Error "database Connection Is Not Opened"
Nov 7, 2010
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..
I have an MS Access 2003 database built that resides on a shared network path at the company I work for.The database works perfectly for users connected directly to the company network.However, when a user tries to open the database while connected remotely to the company network (they can still access the shared path), they receive the following error:The Microsoft Jet database engine stopped the process because you and another user are attempting to change the same data at the same time.At the time that they tried it, they were the only person accessing the database.They tried a local copy as well as a copy on the network shared drive.[code]
I've got a fairly large VB.NET (3.5) project that makes a lot of database calls. So I created a namespace/class just to handle those fuctions. The idea was that this single point of entry into the database would give more control over validating input from users.
So my class looks something like this. (I've chopped some code out for readability, it works just fine except for all the open connections.
[Code]...
So I can close the data reader, but how do I reach back to that original database class and close the connection. If I close it in that original class it will bomb when I try to loop through the data reader the in calling class.I'm sure this is probably pretty obvious but I'm fried from the keyboard.
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.
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
This is what I'm getting when I try to connect my MS Access mdb database to my program. It keeps asking me to enter a connection string and when I do this is the error I'm getting."Format of the initialization string does not conform to specification starting at index 0.
Is there a way to catch a database exception and then redirect to an error page? I have a data access class that I use to make a sql connection and then functions that call it to execute my SQL commands. My problem is that if my database is not available I cannot catch that error. Here is the code I am using in my class[code]...
so for one of my assignments i have to use a databse that the professor provided but every time i attempt to establish a connection to the database that i downloaded it gives me this error, i have tried on both my desktop and laptop with no success. the picture is kind of hard to read but hte error says The 'Microsoft.ACE.OLEDB.12.0' provider is not registered on the local deafult machine.
I am trying to upload a SQL dataBase onto VBasic, but I keep getting a connection error Error version 655, the application useses versions of 612 and earlier.What can I do to fix this error. I am using SQL server 2008 and Visual Basic 2008...
Dim con As New OleDb.OleDbConnection Try con.ConnectionString = "PROVIDER=Microsoft.Jet.OLEDB.4.0;Data Source = D:\project\login.mdb" con.Open() str = "insert into table1 values(" & Text1.text & ",'" & Text2.text & "')" cmd = New OleDbCommand(str, con) cmd.ExecuteNonQuery() [Code] .....
If I insert integer value it will be updated in database every thing is ok but when I want to write some string in my textboxes and want to send them I get connection error.
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]..........
I want to handle errors that might occur when user tries to connect to database. I don't know how to do that.This is my connection string used all over the program:
Using connection As New OleDb.OleDbConnection("Provider=Microsoft.Jet.OLEDB.4.0;Data Source=" + txtFilePath.Text + ";Jet OLEDB:Database Password=" + txtFilePassword.Text + ";") There are a few errors that i faced them myself:
I just bought the MCTS Self-Paced Training Kit (Exam 70-561): Microsoft.NET Framework 3.5 - ADO.NET Application Development, and am trying to do the Lab Exercises now. Allready at the first exercise (point 8), where I am supposed to make an "UNIT TEST",[code]
I've added a database to my application with 2 fields:"ip" address and "started" that holds the number the application was started from that specific IP.I want to upload the database to my site hosted at google.sites. When the program is started it should make a connection with the following cases:
1-no connection with the database (possible no internet available) - it should display an error message
2-there is connection, the IP is not stored on the database, it addes the IP to the database and the field "started" with the value 1
3-there is connection, the IP is stored on the database, it increments the field "started" by 1
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 am using VB 2008 Express and have created an application that connects to a SQL database to populate a datagrid.The application is working properly on my computer but will not on others 'remote connection permissions' error.After some googleing I found that the express version is crippled to only work on local machines that use a database.If I purchase Visual Studio 2008 Standard Edition, import and rebuild my application, will my application be able to run properly on other PC's?
I'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
I have a simple scraper. It works on some websites, but on some there is this Error:
Quote:
IOException was unhandled Unable to read data from the transport connection: The connection was closed
It is occuring at "Dim htmlresults As String = Urlcontents.ReadToEnd()".
'Create the HttpWebRequest object Dim req As HttpWebRequest = WebRequest.Create(URL) 'Set the timeout to 1 second (or 1,000 milliseconds) req.Timeout = 10000
I 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 have written a program which connects to MS sql express 2008 using the string below. This is OK on my computer but when I try to run this on a client computer I get the following message: "An attempt to attatch an auto-named database for file :(C:UsersBarry2010 vb programsadotrialadotrialResults 6.mdf) failed. A database with the same name exists, or specified file cannot be opened, or it is located on UNC share."
This will happen at random, and I can always just catch the error and re-establish connection to the server, but I am confused as to why. When doing lots of inserting into the sql server, I only establish one connection that is public, instead of many little connections. I had my doubts on a public sql connection, but it's been running great, and I've seen no problems until this morning. Again, this random moment I hit an error that stated, sql connection state is broken. Is it bad practice to just accept this error, and when it happens, re-establish the connection?
I am trying to change my windows application I made in vb.net that uses an access database. I do not know where this database will be stored at this time so my plan is to set the connection using code based off a text file that points to the location of the database. Here is the code I have but I know there is something wrong with my syntax because it putting "Provider=Microsoft.Jet.OLEDB.4.0;Data Source=|DataDirectory|IWS.mdb" in both the data source and the database name.[code]...
i am an IT student and i want to understand very well how to program in visual basic.net and how to manipulate its connection to database since my project uses visual basic environment.
I'm just learning VB and would like to know: How do I create VB connection to an Access 2007 DB? I can use the DataGridView to view the table but can not create a connection to add records.
