Any Way To Reset Or Clear DataReader?
Mar 6, 2012Is there an easy way to reset or clear a DataReader so it can be read through more than one time? I found a Close method but not an open method.
View 1 RepliesIs there an easy way to reset or clear a DataReader so it can be read through more than one time? I found a Close method but not an open method.
View 1 RepliesI got on my form textboxes, checboxes but also a groupbox which holds texboxes.
The idea is to be able to clear and reset all of these by clicking a reset button.
At the moment i got this
Private Sub ClearFields()
Dim ctrl As Control
[Code].....
But ofc Me.controls isn't gonna get involved with the stuff in the groupbox.
How do I clear/reset the BackColor of a windows application form? For instance, I have a set of radio buttons, each one changes the color of the background form color, when i reset the radio buttons i would also like to reset the color of the form back to it's original state?
View 2 RepliesI currently have a chart that plots lines of a changing value every time it is called via a timer.
Everything is running as I expected and I am happy, but now I want to be able to press a [STOP] button which will stop the timer and stop the graph from updating, (which I have coded and is now working OK), BUT I then want the code under this [STOP] button to clear everything from the graph, so when I re-start the timer, the graph is cleared and starts plotting fresh points on a clean graph.
The problem I currently have is that when I press the [STOP] button and then press the [START] button, the new lines that get plotted are "added" to the existing lines that are already on the chart, instead of having a new "blank" chart, with no data on it.
So what I am really asking is does anyone know if it is possible to reset a chart clearing everything off it so it is ready to start displaying fresh data?
I was hoping it was something like: "Chart1.Clear" or something simple like that, but I can't seem to find anything that will do it.
I have built up an interface in VB2008 with many textboxs and labels on. When I click "New", I would like to clear all the textboxs and labels, i.e. each with a NULL value. Meanwhile, I also would like to clear all the arrays behind the program, i.e. the arrays which are not shown on the interface but is important for the calculation.The only way I could find out now is to clear the textboxs, labels and arrays one by one. So if there are 100 textboxs, 100 arrays, I have to write 200 lines in total. Obviously, it is not expected. Is there any other quick ways to directly reset everything to the beginning when the interface is just opened?
View 5 RepliesI have an SQL statement like:
SELECT FNAME, LNAME, CITY from EMPLOYEE
How do I create a multi-dimensional array from a datareader which should store values like:
John, Doe, LA
Mike, Johnson, PASADENA
Freddy, Kruger, Long Beach
I have a problem with my project. here is the problem:
My code for login is as follows:
dim conn as SqlConnection = New SqlConnection("Data Source.................)
dim cmd as SqlCommand = New SqlCommand("Loguser",conn)
cmd.CammandType = CommandType.StoredProcedure
[CODE]...
Now the error i get is that "there is a datareader associate with this connection that need to be closed"
Ok, so I am building my own program to control a video player I have through telnet, I have everything else working except one thing.I have a reset button to reset the player, when I press it, it sends the string "Reset" and the unit resets without a problem.But when I add a code to close the winsock connection upon reset, it doesn't send the string to the unit. I am sure what is happening is the winsock is getting closed at the exact same time it is trying to send the string and so it fails to send, how do I make it close winsock AFTER the string has been sent? [code]
View 1 Repliesthis is currently my code to clear my 5 textboxes
Private Sub Button2_Click(sender As System.Object, e As System.EventArgs) Handles Button2.Click
TextBox1.Clear()
TextBox2.Clear()
TextBox3.Clear()
TextBox4.Clear()
TextBox5.Clear()
End Sub
I have a timer that runs every time by itself, and for the code the runs in it I would like to have it clear the dataset before it does anything, the timer runs every 10 seconds, so I tried to do dataset.clear but it would crash if the dataset had no values
View 4 Repliesin hyper teriminal when i press "ctrl+L" is to clear terminal screen how to write the code in vb.net? Hyperterminal is connecting to serial comport.when i try this it work and return line on debug
serialport.writeline ("at+cmgl=1")
i try this but not work and it still show some lines on debug
serialport.writeline (vbcrtl +"L")
serialport.WriteLine("vbCrLf + l")
way to clear textboxes in VB.Net and what is the difference between the two methods? I have also seen people be critical of folk using clear objects on their forms and i can see why but in this case, i am only learning.
txtbox1.Clear()
or
txtbox1.Text = ""
wan to ask about anyone know the code about how to clear all the data inside the data grid view without clear the binding source...
View 1 RepliesIn my winform program (in vb.net) I wrote:
Dim dt As New DataTable
'Get data from DB into dt
'...
[Code].....
But when I run the program, Clear() cleared both dt and dttemp! Why? Aren't dt and dttemp supposed to be two distinct instances of DataTable?
(I finally found a solution - dttemp = dt.Copy() instead of dttemp = dt. But I still can't see why Copy() was necessary in this case.
I am using the StreamWriter to create a log file for my application. However I do not see a method on how to clear the file (make the file blank again). Also before I clear the file I want to rename it so that I can have multiple log files, a new one produced everytime the application runs.
[Code]...
i am working on a search feature for a program i am working on and i found a tutorial online that provides some insight but the actual code, after being modified to fit my aplication, does not work. i get two different errors as of right now, one that tells me "the value of type 'System.data.sqlclient.sqldatareader' cannot be converted to '1-dimensional array of system.data.sqlclient.sqldatareader" and the other that says"argument not specified for parameter 'array' of 'Public shared function... anyway i am kinda new to this and here is what i have so far. any advice?
Private Sub SearchOKButton_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles SearchOKButton.Click
[Code]...
I have the following code which does what it's supposed to do:
objSQLCommand = New SqlCommand("select * from table1", objSQLConnection)
objSQLCommand.Connection.Open()
objSQLDataReader = objSQLCommand.ExecuteReader()
While objSQLDataReader.Read()
[Code]....
But I need to loop through the objSQLDataReader 1 more time. How would I do that?
I got the error message There is an open data reader associated with this command which needs to be closed first by using the following code:
myCommand = New SqlCommand("SELECT BookCode FROM tblBook",myConnection)
myReader = myCommand.ExceuteReader
While myReader.Read
[Code]...
I am copying sample.csv file's content into the new.csv file. But I need to add additional column in new.csv file which holds the default value as "Yes" for each row that exists in old file. Here is the code I have written.
Dim ioFile As New System.IO.StreamReader("C:sample.csv")
Dim ioLine As String
Dim ioLines As String[code].....
The first four columns ID,Name,Number,Amount are present in sample.csv.I am adding additional column Copied which should be "Yes" for each row.
If my Select statement finds data that matches the criteria, how do I get myReader (DataReader) to read each record when there are more then one record found?
Dim myReader As MySql.Data.MySqlClient.MySqlDataReader
myReader = myCommand.ExecuteReader()
If myReader.Read() Then
[code]....
I am trying to tag of some words.There are 5 tag word in my database. but only the first record is coming.i want to
my codes
Public Function tags(ByVal ID As Integer) As String
[code].....
my html code in gridview <%#tags(Container.DataItem("ID"))%>
Hey Friend i am using a form with a *combobox*in which the items i have taken from the
sqldatabase named as balance and that sqldatabase have two columns one is customername and the
another is obbalance now .
In the form i had binded all the customer names from the table and now i have a textbox i want to do is
when the user selects the combobox.selected item any one customer name i need to display the obbalance of the selected customer in tat textbox
[Code]...
two DataReader in one TreeView ?
I am working on a project which requires me to connect to a MySQL database. From there I query the database and need to do work on the returned values.
I can query the database just fine. However, now I need to do work on the results. The two columns returned are user_name and user_password. The rows are the user accounts. I would like to take my query results and put each column into its own arrary().
[code..]
Instead of writing the results to the console, I would like to write each column to an individual array. Is there an easier way to accomplish this task? Or, what is the code I must place within the loop to do this.
i want to fill a Datatable with a Datareader row by row but get an exception because the reader's columns have a different order than the Datatable's columns.
Why and how does a Datatable loads itself with a Datareader correctly, even so it has a column collection with different order?
I need to calculate values for every row so i dont want to load the Datatable completely but row for row. It has 25 columns so i dont want to set it all manually.
There must be a chance to load/fill/add a new row from a datareader without having the same column order(reader.GetSchemaTable?).
Following is what i have but what doesnt work:
Using reader As System.Data.SqlClient.SqlDataReader = command.ExecuteReader
'next line works(configInfo.DataSource is a Datatable)but is inappropriate
configInfo.DataSource.Load(reader)
[Code].....
I 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?
I have a few Oracle procedures that generate/return a large amount of data that I need to write out to a file.I'm currently trying to accomplish with a data-reader. It seems to be working, I've successfully generated a 479mb file without any trouble.It took less than 4 minutes from the time I retrieved the dataReader to complete the file.But the dataReader I get for a particular procedure is crawling.It's unbelievably slow.I modified my code to try and get a better idea of what is going on[code]I'm writing a PL/SQL block that will open that cursor to see if the performance issue exists when I remove the .Net code..
View 3 RepliesAgain I have problem with checking whether DataReader object has data or not?
Dim cmd as SqlCommand
Dim drd as SqlDataReader
cmd = New SqlCommand ("SELECT * FROM Stock", conx)
drd = cmd.ExecuteReader()
[Code]...
This may perhaps be a stupid question but I just can't get it to work.
I have an if clause where I compare a textfield with the value of a datareader.
It looks a little like this if me.txtfield1.text <> reader("field1") OR me.txtfield2.text <> reader("field2") ETC... I do this for a lot of field.
But now I want to check if field2.text is string.empty and if it is I want to skip the comparison for that field.
i want to compare two data values in my database.These two dates belong to two different columns.What i want to compare is if the date of one column greater by 6 months from the date of other column then it should give error.I want to pass this query to database and check,and later on depending on the result want to insert my other functionality?
View 1 Replies