We have developed one multi threaded application in vb.net and we are using Microsoft Access Jet engine 4.0 for database. And when i run the application it execute successfully but after some time it gave an error "Can not open any more table." We searched a lot and we found that we have to close all the connections and all the readers
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Is there a way that I can vew the tables once I have connected to an open connection?[code]...
View 2 RepliesI am using TextFieldParser to read a .txt file and create a DataTable I then filter the table and create 4 new tables I then bind those tables to BindingSources Then Bind ComboBoxs to the BindingSource Then bind TextBoxes to BindingSource I like the user to be able to Open a new file without having to close the program So upon opening a new file I have a sub routine that clears the tables the rows and the columns of each table as well the DataBindings to each control The problem is once I do the Text Binding as such
Me.list1_MLStxt.DataBindings.Add("Text", Subject_Values.BindingSource1, Form10.mls_txt.Text)
Then when I open a new file I get an error message conversion from string"""" to type double is not valid.If I never perform the binding I can open and reopen different files without a problem. So this is causing me to think that the problem is with the way I am clear something? But I am obviously not sureIs there something I am missing to clear everything properly in order to open and read and bind a new file?
i have a few questions about seting up a form.when you creat a new for open the dataset drag and drop the tables to form it creates a top menu bar with pages plus sign and x and save.now when you run the app you need to press the plus sign to add data in the database..is there a way to make it that you dont need to press the plus sign?
View 3 RepliesI have an VB application that I developed in Visual Studio 2008. The back end is SQL. Application stores quite a bit of information and gets updated daily by users. It also connects to AD to get u/p, adds new accounts in AD and adds mailboxes. Users connect to it through Citrix. We noticed big spikes in memory usage. The executable itself is less than 5Mb; if I run it and it opens main form - memory usage jumps to about 19Mb, open a report - it jumps to 80 Mb. If I open the form that is linked to multiple tables - it jumps to 157 Mb. Once users start pulling new information in, update it and connect to AD or Exchange - it could jump to 250 Mb. Also noticed that if user with read only rights has application opened and idle - memory usage constantly changes with a pattern
like 17Mb - 19 Mb - 15 Mb - 17 Mb and so on. This user wasn't even using computer at the time. In general - what could cause such jumps in memory usage? What is the best way to prevent it? On the server we have Windows Server 2003 SE
This code doesnt work it gives an error saying invalid column OrderNumber..
Dim cmd As New SqlCommand
Dim s1 As New SqlDataAdapter
Dim s2 As New DataSet
[Code]......
I'm writing an application that imports and tidy up address data into a cleaned, deduped excel workbook ordered in rows with each column as an address field. One of the issues I've ran into is that we sometimes get a workbook where the multiple address fields are held in a single cell with line breaks. I've written code to extract all of this data out of the excel sheet in to a dataset with each sheet as a table and the address fields contained within. I now want to create a new Excel workbook from this data with the address fields in Row and columns the problem I have is I can Open/create the Workbook but when I try to insert a new Sheet (Table) I get an error saying the Workbook is read only....
Private Sub MakeSimpleXL(ByRef DsTemp As DataSet)
Dim dsTable As Data.DataTable
Dim tblName As String
Dim dsRow As Data.DataRow
[CODE]...
Here is the error: System.Data.Odbc.OdbcException: ERROR [42000] [Microsoft][ODBC Excel Driver] Cannot modify the design of table '3 _ 10$'. It is in a read-only database. at System.Data.Odbc.OdbcConnection.HandleError(OdbcHandle hrHandle, RetCode retcode) at System.Data.Odbc.OdbcCommand.ExecuteReaderObject(CommandBehavior behavior, String
[CODE]...
It looks to me like it is trying to create the table (Sheet) but has the workbook opened as read only....
while trying to run the following code:-
Public
Class Form1
[code]....
I have 2 tables in MySQL database. These table were joined through a query and handled by a dataset. Im displaying these data through setting the dataset as the datasource of my datagridview. But when it comes to Update, Insert and Delete statements, I got an error because the sqlcommandbuilder does not generate statements in multiple tables.I want is, when I press the update button..all the changes made in the datagridview will be updated in the database. Can i make it without creating a datasource in design mode or through smart tag? If I have to manually create an UpdateCommand for adapters..Can I have a code snippet for that?
View 1 RepliesI have a system that gathers raw data from electronic devices, uses that data to populate a set of tables and allow uses to add/edit certain data and report on it. (Kind of basic right...NOT) There are 3 applications that I've written that use the same database.
One is a client that is on 3-4 user machines which allows them to see the data that has come in and work with it.
Two a Data-to-Information process program which takes the raw data, checks up certain information and puts the results into the database.
Third is a data gathering app that interfaces directly with the electronic devices and about 10 times per day places the raw data into a single table in the database.
If a user is in the 'client' application the data processing application crashes all over the place:
1. Database file already in use.
2. Unrecognised Database format
3. File locked exclusively by User on PC X.
Almost always on a different line of code and once when I made it retry over and over I managed to corrupt the database and had to Compact and Repair it to fix it. If no one is using the client everything works perfectly. On each client machine is a database with linked tables to the server machine. The machine that is running the Data processing is the server and the processing is using a database in a different folder that also has linked tables.
I have gone through all the recordsets in the Data Processing application and made sure that they are only using ForwardOnly and Read Only. They edit the data only with Insert, Update or Delete queries. I'm about to do the same in the Client Application as it seems to be the one that is locking everything all the time. The client machines haven't crashed on that error at all. Does it matter which version of Access is on the client and server machines? (All the clients have Access 2003 and the server has 2007 but the Database was created in 2003). Should I just convert the Access database to SQL server and be done with it?
in below code there is syntax error in from Clause but i think every thing looks fine iam using access database thx and relation is fine between thes two table
Public Function GetGridData() As DataTable
Dim dt As New DataTable
Try
[code].....
Using a datagrid, binding to one table, and related to one combobos, I cant update records, cause gives me a violation error. I'm not changing the primary key, so, I dont undersatnd cause this happen. I prepair a example of this error, and it was attached to this message.
View 5 RepliesMy approach is to setup three different queries and save to three different variables and then save the data in the three variables into the new table. I have the new table setup in ms access.As you can see from my code, I had tried many different ways to generate my sql statement but none of them works. Now I am trying to figure out which part of the sql statement goes wrong by testing one by one. The two that is uncomment:
1)Dim SDFH As String = "SELECT SegmentCode FROM SegmentPlantTable WHERE DatePlanted < cdate('" & Date.Today & "')"
2)Dim SDFP As String = "SELECT SegmentCode FROM HarvestTable WHERE DateOfHarvest <
[code].....
I am using VS2008 and SQLite. I have created a database and several tables and am attempting to populate the tables with data from arrays.
The following code (example) works fine but stops after it inserts 30 to 50 records. I am running the VB code in debug mode and when it stops, I press pause to see where it is. It stops on "SQLcommand.ExecuteNonQuery()" and when I press continue (F5) it will insert another 30 to 50 records.
I do not get an error message. Is this a timeout issue? How do I keep the loop running to the end of the array?
Following is example code.
Dim
SQLconnect As New SQLite.SQLiteConnection()
Dim SQLcommand As SQLiteCommand
CODE:.....................
have a datagridview containing 2 tables left joined, so that:table1 LEFT JOIN table 2 ON table1.id=table2.idI get an error whenever I try to edit my datagridview."invalidOperationException was unhandled by the user codeDynamic SQL generation is not supported against multiple base tables."The error points to this line:
da.FillSchema(dt, SchemaType.Mapped)
da.Update(dt) << This line
'da = dataadapter
[code].....
In my datagridview I was fill in using join tables (table1 = pr_employees, table2 = pr_employee_deduction). My problem now is during save button I want to update records from table2 only.[code]
View 3 RepliesWe are presently developing an application, let's call it APP1, which uses a SQL Database which have about 800 stored procedures, 600 tables, etc. APP1 was originally created in order to replace another application, APP0, from which we do not have source code but only SQL tables, Stored Procedures, views, etc. Previous programers of APP1 used some DB objects from this same database and added some other objects specific to APP1 because it becomes bigger than APP0. And we do not need APP0 anymore as APP1 does all what we want, and more.
So, now, we are thinking about a way to find out which objects are used by APP1 in order to remove objects which are ONLY used by APP0.What is the best approach to discover all objects used by APP1 without having to open every single class and form?
Once we will have a complete list of these objects, it will be easy to use a program we bought which detects all dependencies for all SQL Objects specified directly from SQL and remove objects which do not return from any dependencies. Any ideas of how I could get this list without having to go through all our program that have many, many, many classes and forms?
Note : I know, in a perfect world, all calls to PSs and tables should be in a DAL but in the case of the application we're presently working on ... this is not our case! Yippy! (sarcastic yippy) ;)
Note 2 : This application is not using any ORM. So all queries are directly using SqlCommand. So any call to any DB objects are in string format.
I am a newbie and am trying to open a table in SQL Server 2008 table from Visual Basic using ADO and its throwing up a weird fatal error. The error message is:'A fatal error has occurred and debugging needs to be terminated. For more details, see the Microsoft Help and Support web site. HRESULT = 0x80131c08. ErrorCode: 0x0' The code I am running at the time is:
[Code]....
I have a 5 tables in my database and i want to access all my tables togather at a time.e.g.I have a code for one table i.e. rs.Open "select * from Group_info", con, adOpenDynamic, adLockBatchOptimistic. instead of Group_info table i want to access 5 tables also as Login_table,User_info table,group_name table etc. How i do that
View 11 RepliesI have this sub as part of my login / logout system. When this sub is called to login users it works perfectly, but on logout it throws an error that doesn't make any sense to me.
[Code]...
This sets a nonsense email address so that when validate_session searches for a valid email/session combo in the db it trips the destruction of the sensitive session data.
The question boils down to this: Why is the error being thrown when the logout sub calls validate_session?
Error4Unable to open file 'D:ConstruContrWinAppConstruContrWinAppobjDebugConstruContrWinApp.Resources.resources': System Error &H80070020almunji
View 1 RepliesI have this problem says that "the portName cannot be set while the port is open". When this errors occurred, my application on sending sms could not work. Before I edit the application can work but after making some changes and ask help in this forum, the application does not work and gives errors and it says "the portName cannot be set while the port is open".
Imports System.Windows.Forms.Form
Imports System.Text.Encoding
Imports System.Threading
Imports System.IO.Ports
[code]....
I am trying to build a word add in to add xml files to documents, I am under the assumption that Microsoft.Office.Interop.Word.Application.ActiveDocument will work with the document being used, but when I try to use the add in I receive the error: "this command is not available because no document is open " o:
Dim activeDoc As New Microsoft.Office.Interop.Word.Application
Dim currentDoc As Microsoft.Office.Interop.Word.Document = activeDoc.ActiveDocument()
the second line.
im getting this error MySqlConnection.Open() Unhandled Here is the code i'm using
Imports System.Data.SqlClient
Imports MySql.Data.MySqlClient
Public Class LoginForm1
Dim MySqLConnection As MySqlConnection
[code]....
Error when debugging with open database
View 6 RepliesWhen i run my program and try to click on of the button that open anotehr from it says
An error occurred creating the form. See Exception.InnerException for details. The error is: Object reference not set to an instance of an object.[code]....
I'm trying to insert data into a mysql database, I'm using xampp as well if thats of any relevance? I keep getting this error: Connection must be valid and open.
on cmd.ExecuteNonQuery()
I'm following my Microsoft Access application that I've also written as a reference and that works perfectly.' This is the code for inserting into an access database which works and is tryed and tested:
Imports System.Data.OleDb
Public Class frmEnterDetails
'text box variables
[code]....
I have two datareaders: [Code] When i'm running the code i get this error in the highlighted line: "There is already an open DataReader associated with this Command which must be closed first." I used different variables in both readers, why do i get this error? do i have to open a new sqlConnection for this task?
View 13 RepliesI type in openfiledialog1.showdialog() and it says theres in error when i have a openfiledialog on my form Please Respond Quick
View 3 RepliesWhile trying to open a form I get the following error:
An error occurred creating the form. See Exception.InnerException for details. The error is: Index was out of range. Must be non-negative and less than the size of the collection.
Parameter name: index
Previously the form loaded flawlessly. I made several small changes to subs contained in the form, and after that the problem appeared. These changes included some changes in the constructor. I've tried to track down the problem simply by adding message boxes near potential problem areas, and it seems that the exception is thrown before the constructor is even run. The error message baffles me, since I'm not knowingly using any parameters, and the routine opening the form doesn't refer to any arrays (or any other variables).
Here is the part of the source code that the error message refers to:
Private Sub SugNewTagsBtn_Click(ByVal sender As System.Object, ByVal As System.EventArgs)
Handles SugNewTagsBtn.Click
SugNewTagsForm.Show()
End Sub
