I have a basic application that allows pre-defined users to use the application.The Username & passwords along with some other basic user info is stored in a simple access dbIn my application I want a user to login, Username & PasswordI create a connection string, a data adapter and a dataset, I then need to validate the password the user has entered.Would it be best to query the access db directly, or the dataset?
View 5 RepliesI recently switched to V.Studio 2008 and using VB. I can not find in the data toolbox the connection and data adapters. Should I do something else to make this appear so I can drag them in my form.
View 2 RepliesI am working on a huge multiform project for my company, and one of the few issues I am having is that when I am on the Main Menu Form, then go into a specific form (i.e Sales Order, etc.), do updates, changes, or just view data then close the Sales Order Form, if I happen to go back into the Sales Order Form without closing the entire project, then the Sales Order Form will display data instead of opening a blank form like when I first opened it.
Is there something that I should be adding to the Form Close Event to dump all of the data or refresh the data adapters so that if I open the form again, it will display a blank form that is ready to be used like when I first opened it?
I have tried using;
Me.Dispose()
Me.Close()
when closing these subforms, but if I open them again, the data fields (combo boxes and text boxes) will have random data in them.
I have a program that simply checks if the account number and pass word match. And if not it allows you to create it. But i have no idea on how to create something that will hold the data and will allow the user to add and remove sets of data.
View 1 RepliesHow to create the data set, and data adapters in vb.net can any one illustrate with an example. I have used the SQL server, to create the tables.
View 2 RepliesI need to link different arrays of data that I am gathering from different Select Cases.For Example:Araray A, B and C from Case 1Array C, D and F from Case 2 Note: Array C is common between two cases.I know in C++ I could have used Pointers and use SQL in Java.
View 1 RepliesI have inherited an application at work that someone else started creating, right now about 1/2 of it is functional and is in use. My problem is that it is all done in 2.5 ?? and I am trying to step through it all to figure out how it works. I have always created my own binding sources, adapters and data tables.
One of the things I need to do is add a field to the fm_fieldman_master data table. I add the field in the db (SQL Server 2005)table, I come into VS and refresh the datasource, I then add the field to the fm_fieldman_master data table and the Fill,GetDAta() query I go into the designer and create all the attributes for the combo box
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I collect two sets of data from two different databases, This data is now in two collections. I then join/append the one collection to the other and then put it in to a list view.I really would like to order this list view by the first column without the click event.To make this even harder the First column contains Data that is DateTime and i have found that it orders the items by the day number and not the months or years or time.I have found one way but it then cause's me further agony when doing some checks upon the data within the listview later in my code. This answer is to rearrange the format to "yyyy-MM-dd HH:mm:SS" then using the listview.sorting = sortorder.
View 7 RepliesI have only 2 sets of "fixed" numbers used, that I need to be able to toggle between. Particularly, for array sizes/for loops. Is it best to use "Collections" in VB.NET to accomplish this?
View 5 RepliesI have a regular expression that I use to grab data between two sets of id's for example:
<CLASSCOD>70</CLASSCOD>
The regular expression I use is:
(?<=<CLASSCOD>)(?:[^<]|<(?!/CLASSCOD))*
Which works in most case but when I have a single value like this
<CLASSCOD>N</CLASSCOD>
It says there are no matches.
The whole data string looks like this :
<STATUS>PRESOL</STATUS>
<DATE>0601</DATE>
<YEAR>11</YEAR>
<AGENCY>Department of the Interior</AGENCY>
<OFFICE>Bureau of Indian Affairs</OFFICE>
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I have a USB device which creates a Virtual Serial Port on Windows. I am using VB.Net to write and read from the port. My device responds with specific sized set of bytes, but I am finding that SerialPort.Read(byte-array,offset,number-bytes) does not return the full number-bytes but it also does not timeout or generate an exception. Repeated calls return additional fragments (up to 3 calls required). Python code using pySerial does not have the same problem.So, what am I doing wrong here? Am I expecting too much?
Some scenarios are:I write a command to the port and expect to get 4 bytes in response. I get 1 byte first and then 3 bytes on the subsequent call.I write a command and expect 21120 bytes in response. I get 1, 12671 and then 8448 bytes in 3 calls to read from the port.
Here are some excerpts from my code:
Private Sub SetupVirtualSerialPort()
Dim portName As String = "COM" + (m_DeviceContext * -1).ToString
Const baud As Int32 = 9600 '7680000
Const parity As Parity = parity.None
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I am a newbie at VB.net and would like for you to review my code in order to improve its performance.My objective is to append a bunch of ".csv" files into daily data sets. Within a directory I have about 2500 individual text file (.csv). Each file represents minute intraday stock market data for an individual stock covering 5 days or one week of data. This means that each symbol has 1950 string lines..Here is an example of what a string line looks like: "2011-06-27,10:07,48.15,48.15,48.02,48.02,25421". Not that is relevant but these represent Date, time,Open, High, Low, Close & Volume. Since I have 2500 files within a directory; doing some math, I am processing 2500*1950 = 4,875,000 lines. This process takes me about 16 hrs to run.[code]
View 7 RepliesI have a customer and booking data sets on my form. customer id is a foreign key in booking table .but when i click delete button. it gives me an error: The DELETE statement conflicted with the REFERENCE constraint "FK_Booking_Customer". The conflict occurred in database "photoshoot", table "dbo.Booking", column 'Cust_id'. The statement has been terminated. Its a one to many relation between customer and booking. one customer can make many bookings each booking will belong to only 1 customer.
View 1 Replieshow to connect to a database and retrive data in a table using oledb data provider in Microsoft access?
View 2 RepliesI'm trying to connect a VB application (2010) to an MS Access DB by adding a data source from the data menu but I receive this error message "The connection you selected uses a local data file that is not in the current project.Would you like to copy the file to your project and modify the connection ?
If you copy the data file to your project, it will be copied to the project's output directory each time you run the application" and the options are (yes , No , Help)
If I choose Yes I will not be able to make the application 'device independent ' since it will not be copied under the bin , and if I choose No , changes won't be applied to the DB
The control comes up blank??Imports System.Data Imports System.Data.OleDb Public Class Form1
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I'm trying to create a simple Data Grid that will automatically save changes. So far I have a data grid connected to a MS Access 2007 Database that reads the data. I can create new fields in the Data Grid, but I need to program to save the data automatically to the database on update (or on close).
View 6 RepliesI've tried exporting data from an Access 2003 database to Excel in VB.NET using the following [code]...
View 4 RepliesI am trying to read and save data into a access Database but using the rows and colunms valeu can
View 1 RepliesI have a combo box with a data source. This box shows one column of a table and allows me to select one item.Next, I have an ordinary text LABEL that I need to put text from another column of the item selected above.I tried to set the data binding field of the label, but this grabs only the first row or data and shows the selected column. That is nice, but I can not figure out how to update the selected selected ROW when the combo box item is changed.In this case the combo box lists a bunch of inventory parts. When I select a specific part, I need the change the text in a label to show the manufacturer. (like a sub-form). This same behavior will be used in several other places, but the relationships can cascade.
View 4 RepliesHow would you add data source to your combobox from a combobox that is connected to the access atabase?they are both ın the same form of course and the software language ıs Visual Basic. I ve got two comboboxes that I need to connect with eachother combobox1 is showing the "itemsonsell" from the "table_items" table from my access database, the second one should show the "prices" value from "table_items" depending on which "itemsonsell" item is chosen on combobox1,I ve done the solution below,but it didnt seem to be working,it is showing all the "prices" that are under the "table_items" table's "prices" class.
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I'm getting some troubles to add data in a access data base with vb.net applicaion. it shows me the exception System.data.OleDb.OleDbException. my code:
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I have a problem reading data from an RFID-reader. I connect to the reader by tcp and wait for DataAvailable to be true, then reading the data until I got a end of data character. Then I just go back and waiting for a new DataAvailable. This is done in a own thread for the function.
There seems to be some kind of timeout, If I don't got any data in a couple of minutes, then it just sits there in the do/loop waiting for DataAvailable. I hold the card to the RFID reader, it beeps, but there is no data available. I don't get any exeptions, and the information says that the clientsocket is still connected. Are there anything more I can check?
If I put the card to the reader in a minute-interval it seems as this will never occur. So 2-3 minutes idle:ing seems to do this.
Here are my code to read data from the socket, I have taken away some irrelevant code:
Sub test(ByVal ip As String, ByVal port As Integer)
' this sub is meant to run forever
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Im working on a HSD 32 bit data bus to serial converter via a microcontroller. Now first I want to make a sort of data sniffer to read the data bus (32Bit) .All on the controller side is working and the stream of bytes are coming in via RS232 as 4 bytes in HEX like FD,A5,45,8B . I already converted the bytes in Dec and ASCII to determine what is passed true the bus and how fast and stuff.. Now that is all correct and working very well if the LSB (least significant bit) of the 32 data bus is Data line 0 and the MSB (most significant bit) is Data line 31 but if that is not the case I need to invert the 32Bits (like as I would invert the connector on the bus) . How do I best do this using the 4 bytes I send from the micro controller.
Example:
(MSB) 01001000 01100101 01101100 01110000 (LSB)
HEX= 48 65 6C 70
DEC= 72,101,108,112
ASCII= H E L P
I need to invert it with a button to:
(MSB) 00001110 00110110 10100110 00010010 (LSB)
HEX= 0E 36 A6 12
DEC= 14,54,166,18
ASCII= (SO) 6 : (DC2)
I need to control a device with a GPIB port. I have the commands that I need to use to do this; but I don't know which is the sintaxis in Visual Basic.
For example if I need to send a instruction like "START:0.01" to the external device which are the libraries that I have to include?, how should I write the programming line to do this?
The main tasks that I need to program are sending data, receiving data, and saving data
how to get my data out of access and to a data grid. What i want to do is, edit this data in the the data grid and save all alterations to the data grid back to access. There must be a command which copies all the contents of the data grid back to the access database??
View 3 RepliesI'v designed a ms access database table with one field having Datetime datatype. I can Insert data into it from vb.net front end by trns_dt DateTime.Now.DateBut when I fetch records from the tableand assign the dataset datasource as da, it shows datatype mismatch error.
daleDbDataAdapter("SelectDaily_Transactiondtp_from_dt.value dtp_To.value con)
dsDataSet
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I am having an issue on the listbox when the new data value equal to previous data then = to "0". However, I want if the new data value( A ) is equal to the previous data( B ) then ( A ) equal to ( B ).
Delegate Sub ListBoxUpdater(ByRef listbox As ListBox, ByRef str As Object)
Private Sub OnQuoteUpdate(ByRef QuoteUpdate As LingLib.structQuoteUpdate)
UpdateListBox(lbBox, QuoteUpdate.tQuote)
End Sub
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My problem is when the new data comes out from the API, if it is equal to the previous data and it will appear 0. But what i want is the new data comes out is 0 and it will equal to previous data. e.g: first data comes out is 12.00, in above case, if the second data comes out is 12.00 but it will shows 0 which means unchanged. But in my case now, i want if the first data come out is 12.00, then if the next data is unchanged (0) and it will appear 12.00 and so on.
I am currently working on a API. I am having an issue on the listbox when the new data value equal to previous data then = to "0". However, I want if the new data value( A ) is equal to the previous data( B ) then ( A ) equal to ( B ).
Private Sub UpdateListBox(ByRef listbox As ListBox, ByRef str As Object)
If (listbox.InvokeRequired) Then
Me.BeginInvoke(New ListBoxUpdater(AddressOf UpdateListBox), listbox, str)
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i want to create a table that include a current year data and as well as previous data to be compare. here is the example of the table that i want to create: but i want to compare one of the annual data with the previous year. as example i want to compare between the data of current AR of 2007 with the current AR for 2006, Current AR of 2006 with current AR for 2005 and go on~, but i have no idea how to do it.
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