I have a sub that updates a form on certain occasions. Sometimes I need to update a form when some of the entries in my table will still have a NULL value. I used this code to prevent the sub from trying to fill the form fields with NULL data:
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I am looking to programme a button to check if an entry from a textbox exists within a table.
This will done via a button.
how I would code the button to make it query the table?
I am building a data based application using VB 2008 an SQL Express. I need to create textboxes on my form using code, (With & End With) method. I need a simple code string that will allow the app to check if the field to wich the textbox wil be databound is Nul, If so the textbox will not be created.
View 8 RepliesHow to check whether a column is null i use the following code but I got this error "Input string was not in a correct format."
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Is there a faster/easier and more efficient way of checking if an entry exists in SQL then this:
Private Function CustomerCheck()
Dim connString As String = ("Data Source=.SQLEXPRESS;Initial Catalog=BFS;Integrated Security=True;Pooling=True;")
Dim cmdText As String = "(SELECT * FROM Customer WHERE Customer=" + CustomerTextBox.Text.ToString + ")"[code]......
With my application I want to check what list box entry is selected in another app (different process).
View 1 RepliesI've got a program and what I need is for a Timer (running in a different thread) to constantly be checking a TextBox for an entry that is similar to:Quote"(PlayerName)" has joined the server.Where (PlayerName) would be replaced with the players name in the TextBox. What I would need the TextBox to do after it has found this entry is to add (PlayerName) to a listbox. If someone can help me out this far then I can use the same code to get it to remove the player when they leave.Below is a picture of what it should look like inside the program.
View 3 RepliesUsing VB.Net and Sql Server. I want to check the user Entry Value. The User is entering the code in the textbox, before saving to the table, I want to check whether code is already exist in the table or not.
Tried Code
cmd = New SqlCommand("Select code from table where code = '" & textbox1.Text & "' ", Con)
dr = cmd.ExecuteReader()
While dr.Read()
End While
If value is exist, then message to the user "Already Exist" other wise save to the table.
Using this example:-
Dim StoreItem As New Dictionary(Of String , Integer )
StoreItem.Add("CS2a", 6)
StoreItem.Add("DD72b12", 3)
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The second MsgBox will throw a hissy fit. How do I code so I can tell if an entry exists or not beforehand?
I have a database containing usernames and "points". I need to increment the "points" at will. I have the table connected to a sqldatasource.
Here is my current code:
With Users
.UpdateCommand = "UPDATE Users SET points = points + 1"
.Update()
End With
This works great, except, instead of just changing the entry with the username specified by a QueryString, it changes all of the entries and adds one.The sqldatasource has the following select command:
SelectCommand="SELECT * FROM [Users] WHERE ([username] = @username)"
This command makes it so that only entries with the querystring specified username are displayed. This is really my first attempt at SQL.
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What is the best way to compare an Int entry from a table in a case statement?Using SQL server 2008 R2, Visual Basic Express with LINQ to SQL.The code I tried doesnt work:
Private Sub UpdateSetOpt()
Dim db = New ACEDataContext
Dim SRM = From q In db.Settings
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I made some progress and I am succesfully reading in reading in two columns of data to my DataGridView but now I am stuck. I have to search the first column for a particular number the read in that row and put the data in a variable to use, how do I search through this data?
Here is what I have so far:
vb
Private Sub RetrieveContacts()
Dim conn As New OleDbConnection("Provider=Microsoft.Jet.OleDb.4.0;Data Source=" & Application.StartupPath & "myTest.mdb")
Dim adapter As New OleDbDataAdapter("SELECT [PN], [SIZE] FROM MYTABLE", conn)
Dim dt As New DataTable("MYTABLE")
adapter.Fill(dt)
dgContacts.DataSource = dt
End Sub
I use in java JTable looks like a excell sheet create columns and rows and enter data in it.In vb 2008 what control i can use, I think table control layout not supported to data entry it supports control to in it and then add data .
View 1 Replieshow can i control Data Entry in 3 different table with BeginTranaction / Commit /Rollback in vb.net 2008. i am using sql server 2000 at back end and used SqlClient,SqlConnection, ExecNonQuery method.
View 1 RepliesIam trying to link a database to a website. I want the website to allow a user to make a username (OrgID) and password (OrgPassword) and have them apear in my database table (Organizer). This is the code I have so far, but I cannot get it to update the information in the database.
protected void RegisterUser_CreatedUser(object sender, EventArgs e)
{
if (txtUserName.Text != "" && OrgPassword.Text !="")
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I hope someone can help me. I have an ATM machine connected to a server. A form takes a textBox entry as a PIN number and matches it to a card number in the same table which is the primary key. The card number is in a comboBox.Selected Item. I have used a dataset to fill the comboBox as the form loads. I have tried for days and got nowhere.
View 6 RepliesI need to display all the data in that table but it only shows me the last entry.
db.OpenConnection()
strSQL = "SELECT * FROM BaselineTeam WHERE Process = '" & txtProcess.Text & "' " & _
"AND SubProcess = '" & txtSubProcess.Text & "'"[code]......
I am creating data entry form in vb.net. I have three tables 1.orders,2. orderdetails 3.productOrderid- Primary key for Order table and foreign key for Orderdetail table.In Dataentry form , I need when I load form , value of orderid from ordertable should automatically load in orderid colum of ordertable.
View 1 RepliesI have some code which gets child items for a menu via the GetChildren function which takes a list of menuData: Dim builtMenu As New List(Of MenuData)(_rawData.FindAll(Function(item) item.GroupingID = 0))
For Each menuData As MenuData In builtMenu
If menuData.Children IsNot Nothing Then
menuData.Children.AddRange(GetChildren(menuData))
End If
Next
If I check if menudata.children isnot nothing, it always is nothing because the GetChildren function is yet to run (providing the child items, which do exist). If I remove this check and just have this code:
Dim builtMenu As New List(Of MenuData)(_rawData.FindAll(Function(item) item.GroupingID = 0))
For Each menuData As MenuData In builtMenu
menuData.Children.AddRange(GetChildren(menuData))
Next
Then I am presented with a Object reference not set to an instance of an object error on menuData.Children.AddRange(GetChildren(menuData))
I'm trying to create an option to select a specific entry in a SQL table if multiples exists. The Sub listed below is for a textbox (MOTxt) and a button (GotMO) for checking an MO# to pull from SQL. Based on the number entered, will populate other text boxes on the page with that row's data. There are exceptions to this, where the MONumber will be entered more than once with different data associated with each entry. So, here's my situation. If we have a duplicate MONumber listed in the table, it will populate the textboxes with the first entry it finds for an update.I would like to create a dynamic dropdownlist (that displays only if multiples are found) displaying the 'Name' field entries for each MONumber found, then once the correct name is selected from that list, to then populate the textboxes with that selected datarow.Here's my code behind:
Protected Sub GotMONum_Click(ByVal sender As Object, ByVal e As System.EventArgs) Handles GotMO.Click
Dim da As New SqlDataAdapter
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Im pretty use to doing loops (although still relative new to vb) in my code however am having difficulty setting up one that picks up an entry in one data table and then sums a field in another where records have matching criteria. Example:
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What i am trying to do is set up a datagridview on a form that shows the summary data. The time is controlled on the form by a trackbar (output to textbox) and I started setting up a loop using (For/Next) to isolate firstly the matching entries in field 3 (time). This works fine. I then used compute to sum the the field 2. However what i want to do is to loop through table 2 and where entries match i.e. where Field 1 in table 2="A" sum matching entries in table 1 where the DateTime matches.
Details: I want to compare these above two table1 and 2 . The unmatched records should be save in a new table .
objectives
1 Should take input the table and fields we want to match each other.
2 Then after searching or reading the record from table and selected fields save the unmatch records in a new table
All I want to do is check if an object is null, but no matter what I do, if it compiles, it throws a NullReferenceException just trying to check! Here's what I've done:
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I have a dataset. I'd like to check if one item in the dataset is null or zero.
If IsDBNull(ds.Tables(0).Rows(0)("TotalCostPerUnit")) or CInt(ds.Tables(0).Rows(0)("TotalCostPerUnit") = 0 Then
Exit Sub
end if
Dim Conn As ADODB.Connection
Dim Null As String
Dim NullRecordset As ADODB.Recordset
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Im trying to check my database for a null value. If the database is null, then I want it to start the timer, otherwise I want it to skip over some stuff and automatically load the main form.
I am trying to check to see if a DataSet is null or not. If it is I would like to show a MessageBox. For some reason it is not recognizing null returns and skipping the message box and going right to the Else commands. [code]....
View 3 RepliesI have a problem with verifying db null value. Actually I don't know the syntax.
Here is the code.
If Not IsDBNull(Me.DeliveryReviewDataSet.Delivery(Me.CustomerIDListBox.SelectedIndex).Signature) Then
"Signature" is the image field (binary data).
Protected Overloads Overrides Sub Dispose(ByVal disposing As Boolean)
If MyBase.Dispose(disposing) <> DBNull.Value Then
Dispose() = DBNull.Value
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I am getting error
1) Expression does not produce a value.
2)Expression is a value and therefore cannot be the target of an assignment.
I retrieve data from database like below. How do I check whether the value retrieved from database is null?
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i'm working with a database application and i want to check if there is a null value in a specific column but it works only when its not null but if its null it throws an exception automatically
i tried to change the nullvalue property of this column but i'm not able it shows a message that its not a valid property
i tried to change the source code in the code editer but it changes back automatically