I have a combobox that is bound to a DB and works great.
However, when the user adds a value to the table to which the combobox is bound, the combobox keeps the old value and adds the current items in the table.
In this case the table originally held just one record ("2012"). The user added 2013 so the table now shows two records ("2012" and "2013"), but the combobox shows three records ("2012", "2012", and "2013"). UNTIL I exit the app and restart, in which case it correctly reflects the only two records in the table ("2012" and "2013").
I have tried cboYear.Datasource = Nothing, cboYear.items.clear, cboYear.DataBindings.clear and nothing works.
Here is the code:
Try
Dim asql As String = ("SELECT * FROM YearsAvailable ORDER BY CurrentYear")
Dim da As New OleDbDataAdapter(asql, con)
da.Fill(ds)
cboYear.ValueMember = "CurrentYear"
cboYear.DataSource = ds.Tables(0)
cboYear.SelectedIndex = 0
CurrentYear = cboYear.Text
Me.Text = "MSD of Perry Township Compensation Model: " & CurrentYear
Catch ex As Exception
MsgBox("ERROR filling the YEAR control: " & ex.Message.ToString)
End Try
You need to clear ds before Fill it again:
ds.Clear();
da.Fill(ds);
Check this out: DataAdapter.Fill
You can use the Fill method multiple times on the same DataTable. If a primary key exists, incoming rows are merged with matching rows that already exist. If no primary key exists, incoming rows are appended to the DataTable.
Related
So the boss comes to me and says "I want the value of each agent and the project on one line and the average of all the other agents on the next line so I can easily see if they are above or below average."
the table looks like this:
dt.Columns.Add("AGENT", GetType(String))
dt.Columns.Add("PROJECT", GetType(String))
dt.Columns.Add("Sales", GetType(Integer))
dt.Columns.Add("Declines", GetType(Integer))
dt.Columns.Add("Margin", GetType(Integer))
Ok its all good. One row in the datatable is the agent and project. The next row is the average of all the other agents and project like so:
row 1:
John Smith,
ProjectName,
(other column values)
row 2:
John Smith,
ProjectName & " AVERAGE/TOTAL",
(other column values)
The project name is removed in the SSRS report on the AVERAGE/TOTAL line because of space constraints on the piece of paper it is printed on.
I do the sorting by our standard way of sorting a datatable.
Dim dataView As New DataView(dt1)
dataView.Sort = "AGENT,PROJECT"
dt1 = dataView.ToTable
Return dt1
But now the boss has a new requirement later on. He wants to be able to sort by other columns in the table but keep the two rows the (agent/project and the agent/project AVERAGE/TOTAL) together. So in essence he wants to be able to sort not by one row but the two rows together but the sort value could be "AGENT,Margin". Obviously to keep the two rows together I have to find a way to sort the Project value too.
So I am stumped and would appreciate any thoughts you might have. C# ideas are welcome as well.LINQ is fine but it is going to have to become a datatable.
so you create two tables. One with the row values one one with the average values. Loop through the row values and then do another loop inside that loop to match project names. Its a hack but it worked.
If SortValue = "Default" Then
dt1.Merge(dt)
Dim dataView As New DataView(dt1)
dataView.Sort = "AGENT,PROJECT"
dt1 = dataView.ToTable
Else
Dim dataView As New DataView(dt)
dataView.Sort = SortValue
dt = dataView.ToTable
Dim dtCopy As New DataTable
dtCopy = dt.Clone
For Each row As DataRow In dt.Rows
dtCopy.ImportRow(row)
For i = 0 To dt1.Rows.Count - 1
If dt1.Rows(i).Item("PROJECT").ToString.Replace(" AVERAGE/TOTAL", "") = row.Item("PROJECT") And dt1.Rows(i).Item("AGENT") = row.Item("AGENT") Then
dtCopy.Rows.Add(dt1.Rows(i).Item("AGENT"), dt1.Rows(i).Item("PROJECT"), dt1.Rows(i).Item("SALES"), dt1.Rows(i).Item("Declines"), dt1.Rows(i).Item("Margin"))
End If
Next
Next
dt1 = dtCopy
End If
I have 3 compobboxes I have created an import code from a SQL table
The problem when I choose a value from the first compbox
the values of other compbox is changed to be like my choice
I made a separate code for each compbox
But I find it impractical because my project has 90 compoboxes
It needs time to run
Is there a more practical solution?
this is my code...
Dim com As New SqlCommand("select Distinct Name1 from TB_dr", Con)
Dim RD As SqlDataReader = com.ExecuteReader
Dim DT As DataTable = New DataTable
DT.Load(RD)
ComboBox1.DisplayMember = "Name1"
ComboBox1.DataSource = DT
ComboBox2.DisplayMember = "Name1"
ComboBox2.DataSource = DT
ComboBox3.DisplayMember = "Name1"
ComboBox3.DataSource = DT
Only populate a combobox on its dropdown event.
That will make your app faster cause your client may not use them all and if he uses one combobox he would populate a small amount of data only.
And no data is populated on load.
As i look at what you are trying to do which is same data for all comboboxes, you can simply put all your comboboxes in a group, and go through your group to populate them all at once.
like for each cb in that group, cb.datasource = dt.
call the datatable once
I am using SQL in vb.net. I believe I have successfully connected to the database and at the moment I am able to display the information I have received in a message box with:
sql = "SELECT ID FROM LoginInformation WHERE Username = '" & txt_Username.Text & "' AND Password = '" & txt_Password.Text & "'"
DataSets = database.sqlSelect(sql)
MsgBox(DataSets.Tables("LoginInformation").Rows(0).Item(0))
However, I do not want it to show the same cell of the database every time I use this code and I am unsure as to how to display what I am actually looking for with the SQL statement. From the above code, I have tried to find the 'ID' but it will always display the cell located at (0,0)
Any help will be appreciated!
Thanks.
You should loop throw this DataSets.Tables("LoginInformation") to get all the rows and columns.
See this example quoted from here:
Private Sub PrintRows(ByVal dataSet As DataSet)
Dim table As DataTable
Dim row As DataRow
Dim column As DataColumn
For Each table in dataSet.Tables
For Each row In table.Rows
For Each column in table.Columns
Console.WriteLine(row(column))
Next column
Next row
Next table
End Sub
I am writing a program for my lab. Based on a salesordernumer (SO-nr) I need to find the corresponding part number out of a table in access and put it into a variable( Prob a string?). later I need to split the different parts from the partnumber but before that I need to get it out of the MS table. This is de code I use now but I get an error.
Private Sub BtnOphaal_Click(sender As Object, e As EventArgs) Handles BtnOphaal.Click
If conn.State = ConnectionState.Open Then
Dim Sonr As String
Sonr = "SELECT *FROM prodvolg "
Dim SQL As New OleDb.OleDbCommand(Sonr, conn)
Dim DataAdapter As New OleDb.OleDbDataAdapter(SQL)
Dim datatabel As New DataTable("prodvolg")
DataAdapter.Fill(datatabel)
Dim queryString As String = "SELECT [pPart] AS Partnummer FROM [prodvolg] WHERE ([pSonr]='" & txtSOnummer.Text & "')"
Dim command As New OleDbCommand(queryString, conn)
Dim reader As OleDbDataReader = command.ExecuteReader()
While reader.Read()
txtppart.Text = (reader.GetString(1))
End While
reader.Close()
End If
End Sub
As you can see I'm just a beginning programmer.
The error is occuring at txtppart.Text = (reader.GetString(1)) the error message:
A first chance exception of type 'System.IndexOutOfRangeException' occurred in System.Data.dll
Additional information: Index was outside the bounds of the array.
at school I learned programming at ADO system but the future seems to be oledb but I don't understand the OLEdb system good so far. If anyone could help me I would be so happy.
The partnumber is could look like this: "CA-017630-6.35M-1/0-2"
Arrays start at index zero, not one. You have only one field returned by the query
txtppart.Text = (reader.GetString(0))
Also, keep in mind that GetString could fail if your row at index zero contains a null value.
If this is the case I suggest to check for null values with
txtppart.Text = IF(reader.IsDBNull(0), string.Empty, reader.GetString(0))
You are retrieving just one field pPart with your SQL statement, so you'll have just one field on the DataReader. Try with reader.GetString(0), because the arrays starts at index zero
Firstly I used the following to populate the DataGridView:
dta = New OleDbDataAdapter("Select * From [" & ActName & "$B6:E" & LastEntryRow & "]", cn)
dts = New DataSet
dta.Fill(dts, "Detailtable")
DataGridView1.DataSource = dts
DataGridView1.DataMember = "Detailtable"
I then formatted the DataGridView which included the following code:
Dim currencyCellStyle As New DataGridViewCellStyle
currencyCellStyle.Format = "C2"
With Me.DataGridView
.Columns(1).DefaultCellStyle = currencyCellStyle
.Columns(2).DefaultCellStyle = currencyCellStyle
End with
This worked well. Columns displayed their values as $1234.00.
When new values were added to the columns they immediately displayed as $1234.00. (working so far)
If a column did not have any values when the dataset was made, no values showed in the datagridview for that column. (no problem so far)
However, all new values added to the blank column display as 1234.00. Not $1234.00.
I have tried refreshing the DataGridView
I have re-formatted the DataGridView after the change to the cell.
It still displays as 1234.00.
If I save the changes, recreate the DataSet and repopulate the DataGridView all is OK.
I need the DataGridView to reflect the correct format ($1234.00) when new values are added directly to the column?????
If you use this line
DataGridView1.Columns(1).DefaultCellStyle.Format = "C2"
it must be work but if your database column format is not Decimal (but TEXT), this type of format it'll never works.