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POvb.net 4 threads to fill the same database
 

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  1. POvb.net 4 threads to fill the same database
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    <p>Hello i've a loop that last about 2 hours to finish, it gets the data from internet and fills it to a database so i want to divide it to 4 threads, and i am trying to do some testing before i put this to my application.</p> <p>so here is a sample that i wrote to fill one database by 4 threads and i am getting this error "BindingSource cannot be its own data source"</p> <pre><code> Private Sub Form1_Load(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles MyBase.Load Me.DataGridView1.DataSource = Me.bindingSource1 GetData("select * from products") End Sub Public Sub thread1f0() For i = 0 To 500 DataGridView1.Item("PD", i).Value = i + 67 DataGridView1.Item("PDP", i).Value = i + 41 DataGridView1.Item("TPD", i).Value = i + 654 + 6 * 13 DataGridView1.Item("TPDP", i).Value = i + 342 Next End Sub Public Sub thread1f1() For i = 501 To 1000 DataGridView1.Item("PD", i).Value = i + 432 DataGridView1.Item("PDP", i).Value = i + 421 DataGridView1.Item("TPD", i).Value = i + 414 DataGridView1.Item("TPDP", i).Value = i + 42 + 4 Next End Sub Public Sub thread1f2() For i = 1001 To 1500 DataGridView1.Item("PD", i).Value = i + 4452 DataGridView1.Item("PDP", i).Value = i + 34 DataGridView1.Item("TPD", i).Value = i + 123 DataGridView1.Item("TPDP", i).Value = i + 44 Next End Sub Public Sub thread1f3() For i = 1501 To 2000 DataGridView1.Item("PD", i).Value = i + 423 DataGridView1.Item("PDP", i).Value = i + 423 DataGridView1.Item("TPD", i).Value = i + 423 DataGridView1.Item("TPDP", i).Value = i + 423 / 2 Next End Sub </code></pre> <p>'//////////////////////////////////////////////////////////////////////////////////////////</p> <pre><code> Private Sub Button1_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button1.Click thread0 = New System.Threading.Thread(AddressOf thread1f0) thread0.Start() thread1 = New System.Threading.Thread(AddressOf thread1f1) thread1.Start() thread2 = New System.Threading.Thread(AddressOf thread1f2) thread2.Start() thread3 = New System.Threading.Thread(AddressOf thread1f3) thread3.Start() End Sub Public Sub GetData(ByVal selectCommand As String) Try Dim connectionString As String = "Provider=Microsoft.ACE.OLEDB.12.0;Data Source=" &amp; strFileName Me.dataAdapter = New OleDbDataAdapter(selectCommand, connectionString) Dim commandBuilder As New OleDbCommandBuilder(Me.dataAdapter) Dim table As New DataTable() table.Locale = System.Globalization.CultureInfo.InvariantCulture Me.dataAdapter.Fill(table) Me.bindingSource1.DataSource = table Me.DataGridView1.AutoResizeColumns( _ DataGridViewAutoSizeColumnsMode.ColumnHeader) Catch ex As OleDbException MessageBox.Show(ex.Message) End Try End Sub </code></pre>
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    1. This table or related slice is empty.
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    1. USuser1570048
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    1. This table or related slice is empty.
    1. This table or related slice is empty.
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    1. COWhy do you think that using threads will help? Chances are that IO is the bottleneck, and adding threads will not help with that.
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    2. COwell it might not help, but i just want to learn how to use them so i wonder why is that exception generated
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    3. COI would say that the error has nothing to do with threading. How are you binding your data? Are you binding a control to itself?
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