Cannot Store Retrieved Values From Database To Array
Mar 21, 2011
is that instead of receiving data from one row and assigning it to the same array Im receiving data from multiple rows, but the information is the same because its from the same one column from the database. The error I keep getting is 'index out of bounds of array'
here is the code
What it does is it loops through once and retrieves the first value from the db then it throw the exception when it goes to retrieve the second value.
Dim qBkNum As String = "SELECT BookingNum FROM Bookings WHERE BookingID = '1'"
Dim bkNum(5) As String
Try
I have a database in my app which loads and displays some information on a form by binding the Comboboxes and Textboxes. However, I need to get some of the other values from the database for calculations before they are displayed on the form and I can't seem to find out how to do this.I could bind a couple of Textboxes to the database and then use those values to calculate, but it doesn't seem like a very efficient way of doing things.The dataset is created using the wizard and the controls are linked in the UI.
I am trying to create a "Generate Number" application. It needs to generate numbers ( 1 - 100 ) and add them to the array. I have the numbers generated already and outputed into a list box. but I am not sure on how to add them to the array.
I have generated the numbers using for...next and do while loops. But I haven't been able to get the right syntax to be able to add the numbers into the array. [code]/...
I have the following code which obtains the compass direction from a degree value. I'm new to VB.Net and was wondering what is the best way to store the values, in an Enum or an Array?
I'm trying to convert old code to VB in VS2005. The code I'm working on is used to store values in a string, which will then be handed to a proprietary scramble function. This function is a given in this case. I've already switched from a string to an array of bytes in my .NET code.
The old code (VBA) was using a string value to store the data, example function for Double value: Private Function DoubleToStr(ByVal value As Double) As String Dim Bytes(7) As Byte ' 0-7 Double is 8 bytes Dim n As Long CopyMemory(Bytes(0), value, 8) DoubleToStr = "" For n = 0 To UBound(Bytes) DoubleToStr = DoubleToStr & Chr(Bytes(n)) Next n End Function
The code basically copies the memory contents (using API call CopyMemory) of the memory (held by the double variable) to the memory held by a byte array. It then reads the byte array and converts it into a string. Workarounds could be to convert a bool or long to a string, though that would be expensive in terms of memory/storage eg. 1234564787 would be 10 bytes in a string where as a long is only 4 bytes (factor 2.5 increase).
How to retain the original precision? Converting it to a string would result in endless numbers. Another problem (at least I think it could be) is that in VBA the variables are rather simple, but in .NET they are all objects, so how to retrieve the actual memory location of the value? let alone garbage collection moving stuff around. How to get those variables stored in my byte array?
I am attempting to teach myself visual basic and I cannot figure out how to send a calculated value (on a button click) into a one-dimension array and then recall the last five values in a message box when the user exits.
Here's what I have:
Public Class frmInvoiceTotal Dim totals(4) As Decimal Private Sub btnCalculate_Click(ByVal sender As System.Object,
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In my example, i use a class array to which I assign values looping through textboxes in my form. Using the button Store (btnStore) the values are perfectly assigned to the array (i use an msgbox to check).The problem is that when i created another button (btnTest) to test if these values can be read outside the btnstore code, I get an error (NullReferenceException unhandled) which informs me to use the new keyword (cannot be used with arrays).I suppose the same applies when trying to access the array from another form. The question is how can i assign the values to the array "forever" and be accessed from "everywhere" in my program ?(tried public, friend, redim preserve the array with no luck).
I would like to read values set in a string that's retrieved from the Web, I've already got the string in a string called Webdata.The string is like so...
"Info" { "Name" { "Name1""Value1"
[code]....
I need to set Value1, Value2, Value3 as strings that I can use.
The following is the code i used to get the value from textbox to listbox and store all the listbox values to the access database at the runtime.In the database, i have only one field called num which is been set as a multivalue field using the lookupwizard. But actually what happens is ,no error is occurred,but the value is not updated in the batabase.
vb.net
Imports System.Data.OleDb Public Class Form1 Dim conn As OleDbConnection[code]...
I would like to retrieve a single column of about 800 rows in a table and save these values in an array so as to reference them later on. How can I do it? I tried:
[code]...
And it didn't work. The col1 is of type Int64 and so is the array prev_ob(). Please let me know how I can save it to an array.
I'm using VS 2010 and MySQL 5.5. I've got a data grid view displaying the results of queries entered by the user, shown below. It works; the trouble is that if there's an image in the results, you'll only see a cell-sized very long thin strip of it.
So I want to a) resize any images to a reasonable thumbnail height (say, 100 pixels, naturally maintaining aspect ratio) when displaying them, and b) resize the row to fit them.[code]...
I am trying to select multiples rows from a database table and insert the text into several "label" controls. For example, if the database search returns 5 results. then insert the first row's text into label 1, the second row's text into label 2, and so on. The number of rows will be variable. I was thinking of a while statement. I am having a problem understanding how to even seperate multiple rows from a query in VB. Would using an array for the query results be the right way to go? row one would be row(0), row two's text would be row(1), etc.
I am trying to program a noise reduction algorithm that works with a set of datapoints in a VB.NET DataTable after being helped with my other question. Basically, I want to take two integers, a coordinate value (yCoord for example) and a threshold smoothing value (NoiseThresh), and take the average of the values in the range of (yCoord - NoiseThresh, yCoord + NoiseThresh) and store that number into an array. I'd repeat that process for each column (in this example) and end up with a one-dimensional array of average values. My questions are:
1) Did anything I just say make any sense ;), and
2) Can anyone help me with the code? I've got very little experience working with databases.
I am trying to create the following program Store in a 1d array a set of 5 place names and in a 2d array the distances between the places. Ensure that the order of the places is the same in both arrays. When the names are places are input the distance between them is displayed. If they are not both in the table a suitable message is displayed
Dim town(1 To 5) As String
Dim Dist(1 To 5, 1 To 5) As Integer
Dim First As Integer
[CODE]......................
I think the best way forward is pass a parameter to the function findnumber.
I want to reading in a excel file and extract the sCodenumber sDescription ans the sStatus and store them in a array : StatusComposeArray(5200) As MyCompose. After this I need this array for comparing outside this class. But as can you see the array is defined inside the sub: ReadingIn_ExcelFilesCompose [Code]
I have an array of people stored in a custom structure array... how can i copy this array to a temp array so that the temp array has all the same values as the original custom array?
I am trying to store 5 values and an associated unique key. I need to search for this key and update the 5 associated values. I'm guessing I would use an object as the value but how do I get the values out from the object?
I am building VB.NET application that takes data from text files that are exported from a legacy DOS program. These are written to a datatable and displayed in a datagridview. Right now my code simply loops through the datagridview and inserts the data into the database (SQL Server). There is a requirement now that the client number must be checked before the insert to see if it exists in the database. If it does, then the value of one field (tax rate) is checked against the value of the field in the datagridview. If there is a difference, then the rate is to be updated in the database and the data that was in the database is to be written to a history table for audit purposes. If the client number is not there, then we are to do the insert (which is already written). I want to know what is the most elegant and efficient solution for this problem.
I need to compare what is in the database table with what is in the datagridview, update the history table for records that exist, and then insert new records.
I am creating a maths programs that draws graphs for the user. so far i have placed 22 values into an array and now i need to import them to excel, draw the graph and import the graph back into the program to display them.[code]...
I am using Visual Basic express edition 2008.I am trying to know if a value in a single dimensional array is repeated in the array. If yes, then multiply one of them by 100. For example:
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Here is my select stament to store values when username and password and check boxes are check
com = New OleDbCommand("INSERT INTO Users (UserName,Password,IsAdmin,Read,Write,Change,REMOVE,User_st) VALUES ('" & txtusername.Text & "','" & txtpassword.Text & "'," & CInt(chkIsadmin.Checked) &
[Code]...
My problem is this wehen i add new record to my db it saves values like this the value of read column is as follows read = 1 when check box is checked and read = 0 when check box is checked but i want to save true or false instead 1 and 0 how to achieve this using vb.net and my db is Oracle.
