I have this Access Database. It has 6 Columns: ID | Class Name | Class Code | Class Room | Grade | Teacher My ID is the Unique Column that I need to reference back too when Updating my other Fields so I get the correct field. How do I do this? Properly.
I've been thinking of a method but I doubt it would work. First I would start off selecting all the ID's and then LOOP through all of them, and then rewrite them to to + 1 Each time I make a Delete, so Each Time it will be a consistent 1 2 3 4 5 6 7 8 9 10 .... etc... Then I can reference from that to my Combo Box Selected Index + 1 to get the Correct Row which corresponds with the Selected Item.
Alright, I have this Access Database. It has 6 Columns: ID | Class Name | Class Code | Class Room | Grade | Teacher
My ID is the Unique Column that I need to reference back too when Updating my other Fields so I get the correct field.How do I do this? Properly.I've been thinking of a method but I doubt it would work.First I would start off selecting all the ID's and then LOOP through all of them, and then rewrite them to to + 1 Each time I make a Delete, so Each Time it will be a consistent 1 2 3 4 5 6 7 8 9 10 .... etc... Then I can reference from that to my Combo Box Selected Index + 1 to get the Correct Row which corresponds with the Selected Item.Will this work? Or will I still need a Unique Fields that I reference back too.
I'm trying to make a method that can get unique values from a specified column of a DataTable. The problem is that the column may be string, integer, etc. I'm not sure what type of variable the (Of T) is.
Private Sub GetColumnUnique(ByVal dbTable As DataTable, ByVal ColumnNumber As Integer, ByVal ColumnType As ???) Dim results As List(ColumnType) = (From item In dbTable.AsEnumerable Select item.Field(ColumnType)(ColumnNumber)).Distinct.ToList End Sub
For each loop through a DataSet, I need to store the values of 2 columns (we'll call them ColumnA and ColumnB) so that I can use them to search the same DataSet again later.The DataSet stores the results of a search and places the value of ColumnA into a ListBox as a new item.When the user clicks on this ListBox item, the application will loop through the DataSet again using the value of ColumnA and the value of ColumnB as criteria to identify the correct row in the DataSet to return.This would be a lot simpler if the value for ColumnA was unique every time, but a value will inevitably be repeated on occasion. That's where ColumnB comes in. This column's value is likely to be unique 90% of the time, and, given the nature of the information in the DataSet, if either column duplicates, the other won't.So I've thought of adding the values for ColumnA and ColumnB into a 2 dimensional dynamic array, but I'm doing something wrong apparently.[code]
currently, what i want to do is, add a column in a table "default" during runtime. Well, I've got that covered already.
The problem is, the column names are actually taken from the users input through a textbox or drop down list and of course, if the same column is added already in the table, it generates an error since it has to be unique.
That is why i wonder if it is possible to know if a column already exists without viewing the form which contains the grid view of that table?
I'm using vb.net on vb 2005, I create datagrid view that when i click search button on the main form. It will show datagrid view that I want and when i click OK to select any record, the selected record will show on the desire text box in the main form. The problem is the record i choose is record no. 5 of all 10 record but the Bindingnavigator tools bar show that it's the first record of all 10 and when I click Next record arrow, the error message show that the 'PK column name' is unique and the 'value of the PK from my selected record' is already exist. [Code]
For my database I need to create unique numbers and insert them in the column "ID". Can I add them via a SQL query? The numbers would simply be 0001 to whatever.I'm using the "Show Table Data" gui.
I'm using vb2005. I'm writing a little application which allows a person to type in a new value in a combobox (which I've bound to a field in a table) which can be updated to the database. I then refresh the dataAdapter by clearing it and re-filling it again when the user saves a new item. That part works fine. My problem occurs when the user selects a stationary item from the combobox. The first select works fine until they try to select another item. Then I get the following error: ConstraintException was unhandled: Column 'TYPE' is constrained to be unique. Value 'False' is already present.
My query returns 4 columns. One column is a unique identifier for the record. I'm trying to hide that column so the user doesn't see it. I'm going to add an edit button and hopefully I'll be able to allow the user to click on the record's edit button and edit only one of the remaining 3 columns and I expect I'll need that hidden value to do the update. I've got code below but it doesn't work. It gives me an exception, "Index was out of range. Must be non-negative and less than the size of the collection. Parameter name: index ".
Dim MySqlCommand As New SqlCommand MySqlCommand.Connection = MySqlConnection MySqlCommand.CommandText = "SELECT ..................." MySqlConnection.Open() GridView1.DataSource = MySqlCommand.ExecuteReader [Code] .....
I'm using an Infragistics UltraWinGrid with a column of drop-down boxes. I don't want the user to be able to select the same value for multiple rows in that column. Is there a simple (or heck, I'd settle for advanced) way to do this? I'm using VB.NET
-EDIT-
I tried setting a filter on the data source for the drop-down box. But when I did that, the values in the other boxes in that column started disappearing (not the values themselves, but the descriptions that they were supposed to represent, so instead of reading "Information", it just said "1"). All of the cells in a column refer to the same combo box, so if you filter out a value from the data source for one of them, you filter it out for all of them. I'm currently trying to catch a CellChange event and check against all other currently-used values. If it was already used, I would put up a message saying as much and revert back to the old value. However, the value comes back as the previously-saved one, so... not helpful. About to see if I can use the "text" property.
How can I query a DataTable to find all of the unique values in a column? SQL has the 'unique' or 'distinct' keywords, but I dont know how to do this against a DataTable.
I am using VB .Net to access the eBay API and store all completed orders in a database. This database is then fed into a proprietary shipping system, which can not handle an order number larger than 20 characters. eBay returns an order number like so 230407279314-680141236013 which is too long. The order number is always 12 numbers a hyphen and 12 more numbers. What I need to do, is turn this (the result can be alpha numerical) into a shorter, unique order key to store in my database alongside the true orderId (so that this can be referenced by the shipping software instead of the actual order number). The reason for the 20 character limit is the barcode algorithm used. Is there any way to achieve this in VB .Net 2010? This number can be anything unique, so long as it does not exist already (even a good uniqueid function would work, but I would have to query the database to make sure it isn't taken)
How generate the unique no. 1,2,3 and so on .... on button click of each new user ..
the code mentioned below is a readwrite coding in vb.net ...
but the problem is it generate the same id for different users on button click event... but i want the no. of times button clicked the new ids will be generated
Protected Sub Button1_Click(ByVal sender As Object, ByVal e As System.EventArgs) Handles Button1.Click Dim FILE_NAME As String = Server.MapPath("counts.vbi")
I have a datagridview that seems to be working fine until the user adds a name into the unique name column that already exists. I am getting this: System.Data.ConstraintException: Column 'Name' is constrained to be unique. Value 'test' is already present. where and how I capture this error and prevent the users from adding another name, case insensitive, to prevent this huge error from coming up?
Unique constraint - these columns currently doesn't have unique values..?? I have created Unique Constraint with 3 columns. My code works perfectly but once - two users @ same time entered same data and somehow it saved in DB; after that incident. This UniqueConstraint gives me error - These columns currently doesn't have unique values. How can I check if user enters this kind of entry or how can I restrict the Entry?
Sub emailConfirm() Dim email As String = txtMail.Text Dim name As String = txtPrenom.Text + txtNom.Text[code]....
note:I want to send Link contains a unique identifier and verify the unique identifier in the login.aspx.I don't know when to do this...I found nothing interesting on the net ...
I have a table in an SQL database bound to a datagridview and am having an issue with understanding what happens when I add a new data row.
My datatable is built in code with the first column created using this sql command...
vb
cmdString = String.Format("CREATE TABLE {0} ({1} INT IDENTITY(1,1) NOT NULL, ", tableName, columnNames(0))
after that there a a number of other columns added to the command to build the table. After the table is created, I fill the datatable and bind the datagridview using this code....
vb Dim cmdString As String = String.Format("SELECT * FROM {0}", DB_DATALOG_TABLE_NAME) DataLogAdapter = New SqlDataAdapter(cmdString, dBConnection) DataLogTable = New DataTable
[Code].....
This is where my understanding is falling. Because I have created the datatable's first column with the NOT NULL key word, an exception throws when I try to update the data adapter because the first column of the data row is empty By creating the table with the first column the IDENTITY key word, doesn't that imply that the database will generate the value for that column? If so, when I add a new datarow, how does the identity column get filled?
creating unique IDs for each row in a table, to avoid duplicates when inserting the data to a server. The table looks like this:
+--------------+----------+------+-------------+ | brikkenummer | tid | post | anvendt_tid | +--------------+----------+------+-------------+ | 3086360 | 09:43:02 | 98 | 09:43:02 |
[code]....
"Brikkenummer" is the number of a device that each person carries with him/her, and "tid" is the time the runner has passed a specific post. The post he/her has passed is described in the column "post".Out of these three columns, is it possible to generate some kind of unique ID? The ID that is generated have to be the same if a row is displayed twice or more, to avoid duplicate entries.
Using VB.NET and SQL Server 2005//In DataGridView n number of rows was displaying. Suppose I edit some value in the datagridview cell then I click save means it should update in the table also. Suppose I click add button means it should add a new row in datagridview.
I am creating files and then allowing the User to browse through the files via a ComboBox. I decided to name each file the current date. In order to create multiple reports each time the application is ran, each report needs a unique name.
The idea is that if they run a report once a day they'll have a unique report each day. But, then I realized that it is feasible that User could run a report more than once a day. So, I decided to create an integer and increment it each time the report has been ran. Then append the file name with that integer. So, report one of that day would show something like this:
12-22-2009_1 and so on.And this works just fine. But, if the user decides to close the app and then run the report later that day, the variable has been reset and no longer works as needed.I'm using a StreamWriter to create the file.
Basically I'm adding a registration feature into my program, or a similar thing to that. So, when you purchase you can install up to 3 copies (for example), but not more.To do this, I need to know some kind of information that is unique to each computer (to store in my database online), I thought of the name of the computer, but that isn't unique, obviously.
I try an update but I get an error"The Index was out limits.I shouldn't be negative and should be smaller than size of the collection" This concern this line in debug "Dim courseId As String = gridViewCourse.DataKeys(e.RowIndex).Values("CourseId").ToString()" This my grid asp code
