VB.Net Tutorial/Database ADO.net/DataTable

Filter DataTable by a logic condition

<source lang="vbnet">Imports System.Windows.Forms Imports System.Data Imports System.Data.OleDb public class CreateDataTableAndFilteredByLogicCondition

  public Shared Sub Main
       Application.Run(New Form1)
  End Sub

End class

Public Class Form1

   Private Sub Form1_Load(ByVal sender As System.Object, _
    ByVal e As System.EventArgs) Handles MyBase.Load
       Dim contacts_table As New DataTable("Contacts")
       " Add columns.
       contacts_table.Columns.Add("FirstName", GetType(String))
       contacts_table.Columns.Add("LastName", GetType(String))
       contacts_table.Columns.Add("Street", GetType(String))
       contacts_table.Columns.Add("City", GetType(String))
       contacts_table.Columns.Add("State", GetType(String))
       contacts_table.Columns.Add("Zip", GetType(String))
       contacts_table.Rows.Add(New Object() {"A", "A", _
           "1234", "B", "A", "11111"})
       contacts_table.Rows.Add(New Object() {"B", "B", _
           "22", "B", "C", "22222"})
       contacts_table.Rows.Add(New Object() {"C", "C", _
           "3", "P", "K", "33333"})
       contacts_table.Rows.Add(New Object() {"", "D", _
           "4", "P", "KS", "44444"})
       grdAll.DataSource = contacts_table
       grdAll.CaptionText = "All Records"
       
       Dim dv_name As New DataView(contacts_table)
       dv_name.RowFilter = "FirstName >= "A""
       grdName.DataSource = dv_name
       grdName.CaptionText = "LastName >= E"
   End Sub

End Class <Global.Microsoft.VisualBasic.rupilerServices.DesignerGenerated()> _ Partial Public Class Form1

   Inherits System.Windows.Forms.Form
   "Form overrides dispose to clean up the component list.
   <System.Diagnostics.DebuggerNonUserCode()> _
   Protected Overloads Overrides Sub Dispose(ByVal disposing As Boolean)
       If disposing AndAlso components IsNot Nothing Then
           components.Dispose()
       End If
       MyBase.Dispose(disposing)
   End Sub
   "Required by the Windows Form Designer
   Private components As System.ruponentModel.IContainer
   "NOTE: The following procedure is required by the Windows Form Designer
   "It can be modified using the Windows Form Designer.  
   "Do not modify it using the code editor.
   <System.Diagnostics.DebuggerStepThrough()> _
   Private Sub InitializeComponent()
       Me.SplitContainer1 = New System.Windows.Forms.SplitContainer
       Me.SplitContainer2 = New System.Windows.Forms.SplitContainer
       Me.grdAll = New System.Windows.Forms.DataGrid
       Me.grdCO = New System.Windows.Forms.DataGrid
       Me.grdName = New System.Windows.Forms.DataGrid
       Me.SplitContainer1.Panel1.SuspendLayout()
       Me.SplitContainer1.Panel2.SuspendLayout()
       Me.SplitContainer1.SuspendLayout()
       Me.SplitContainer2.Panel1.SuspendLayout()
       Me.SplitContainer2.Panel2.SuspendLayout()
       Me.SplitContainer2.SuspendLayout()
       CType(Me.grdAll, System.ruponentModel.ISupportInitialize).BeginInit()
       CType(Me.grdCO, System.ruponentModel.ISupportInitialize).BeginInit()
       CType(Me.grdName, System.ruponentModel.ISupportInitialize).BeginInit()
       Me.SuspendLayout()
       "
       "SplitContainer1
       "
       Me.SplitContainer1.Dock = System.Windows.Forms.DockStyle.Fill
       Me.SplitContainer1.Location = New System.Drawing.Point(0, 0)
       Me.SplitContainer1.Name = "SplitContainer1"
       Me.SplitContainer1.Orientation = System.Windows.Forms.Orientation.Horizontal
       "
       "SplitContainer1.Panel1
       "
       Me.SplitContainer1.Panel1.Controls.Add(Me.grdAll)
       "
       "SplitContainer1.Panel2
       "
       Me.SplitContainer1.Panel2.Controls.Add(Me.SplitContainer2)
       Me.SplitContainer1.Size = New System.Drawing.Size(519, 485)
       Me.SplitContainer1.SplitterDistance = 180
       Me.SplitContainer1.TabIndex = 2
       Me.SplitContainer1.Text = "SplitContainer1"
       "
       "SplitContainer2
       "
       Me.SplitContainer2.Dock = System.Windows.Forms.DockStyle.Fill
       Me.SplitContainer2.Location = New System.Drawing.Point(0, 0)
       Me.SplitContainer2.Name = "SplitContainer2"
       Me.SplitContainer2.Orientation = System.Windows.Forms.Orientation.Horizontal
       "
       "SplitContainer2.Panel1
       "
       Me.SplitContainer2.Panel1.Controls.Add(Me.grdCO)
       "
       "SplitContainer2.Panel2
       "
       Me.SplitContainer2.Panel2.Controls.Add(Me.grdName)
       Me.SplitContainer2.Size = New System.Drawing.Size(519, 301)
       Me.SplitContainer2.SplitterDistance = 173
       Me.SplitContainer2.TabIndex = 0
       Me.SplitContainer2.Text = "SplitContainer2"
       "
       "grdAll
       "
       Me.grdAll.DataMember = ""
       Me.grdAll.Dock = System.Windows.Forms.DockStyle.Fill
       Me.grdAll.HeaderForeColor = System.Drawing.SystemColors.ControlText
       Me.grdAll.Location = New System.Drawing.Point(0, 0)
       Me.grdAll.Name = "grdAll"
       Me.grdAll.Size = New System.Drawing.Size(519, 180)
       Me.grdAll.TabIndex = 0
       "
       "grdCO
       "
       Me.grdCO.DataMember = ""
       Me.grdCO.Dock = System.Windows.Forms.DockStyle.Fill
       Me.grdCO.HeaderForeColor = System.Drawing.SystemColors.ControlText
       Me.grdCO.Location = New System.Drawing.Point(0, 0)
       Me.grdCO.Name = "grdCO"
       Me.grdCO.Size = New System.Drawing.Size(519, 173)
       Me.grdCO.TabIndex = 1
       "
       "grdName
       "
       Me.grdName.DataMember = ""
       Me.grdName.Dock = System.Windows.Forms.DockStyle.Fill
       Me.grdName.HeaderForeColor = System.Drawing.SystemColors.ControlText
       Me.grdName.Location = New System.Drawing.Point(0, 0)
       Me.grdName.Name = "grdName"
       Me.grdName.Size = New System.Drawing.Size(519, 124)
       Me.grdName.TabIndex = 1
       "
       "Form1
       "
       Me.AutoScaleDimensions = New System.Drawing.SizeF(6.0!, 13.0!)
       Me.AutoScaleMode = System.Windows.Forms.AutoScaleMode.Font
       Me.ClientSize = New System.Drawing.Size(519, 485)
       Me.Controls.Add(Me.SplitContainer1)
       Me.Name = "Form1"
       Me.Text = "Contacts"
       Me.SplitContainer1.Panel1.ResumeLayout(False)
       Me.SplitContainer1.Panel2.ResumeLayout(False)
       Me.SplitContainer1.ResumeLayout(False)
       Me.SplitContainer2.Panel1.ResumeLayout(False)
       Me.SplitContainer2.Panel2.ResumeLayout(False)
       Me.SplitContainer2.ResumeLayout(False)
       CType(Me.grdAll, System.ruponentModel.ISupportInitialize).EndInit()
       CType(Me.grdCO, System.ruponentModel.ISupportInitialize).EndInit()
       CType(Me.grdName, System.ruponentModel.ISupportInitialize).EndInit()
       Me.ResumeLayout(False)
   End Sub
   Friend WithEvents SplitContainer1 As System.Windows.Forms.SplitContainer
   Friend WithEvents grdAll As System.Windows.Forms.DataGrid
   Friend WithEvents SplitContainer2 As System.Windows.Forms.SplitContainer
   Friend WithEvents grdCO As System.Windows.Forms.DataGrid
   Friend WithEvents grdName As System.Windows.Forms.DataGrid

End Class</source>

Output data in DataTable to XML file

<source lang="vbnet">Imports System.Data Imports System.Data.OleDb Imports System.IO Imports System.Windows.Forms public class DataTableToXML

  public Shared Sub Main
       Application.Run(New Form1)
  End Sub

End class

Public Class Form1

   Private Sub Form1_Load(ByVal sender As System.Object, _
    ByVal e As System.EventArgs) Handles MyBase.Load
       Dim scores_dataset As New DataSet("Scores")
       Dim students_table As DataTable = scores_dataset.Tables.Add("Students")
       students_table.Columns.Add("FirstName", GetType(String))
       students_table.Columns.Add("LastName", GetType(String))
       students_table.Columns.Add("StudentId", GetType(Integer))
       students_table.Columns("StudentId").Unique = True
       Dim first_last_columns() As DataColumn = { _
           students_table.Columns("FirstName"), _
           students_table.Columns("LastName") _
       }
       students_table.Constraints.Add( _
           New UniqueConstraint(first_last_columns))
       " Make the TestScores table.
       Dim test_scores_table As DataTable = _
           scores_dataset.Tables.Add("TestScores")
       " Add columns to the TestScores table.
       test_scores_table.Columns.Add("StudentId", GetType(Integer))
       test_scores_table.Columns.Add("TestNumber", GetType(Integer))
       test_scores_table.Columns.Add("Score", GetType(Integer))
       " Make the combined StudentId/TestNumber unique.
       Dim studentid_testnumber_score_columns() As DataColumn = { _
           test_scores_table.Columns("StudentId"), _
           test_scores_table.Columns("TestNumber") _
       }
       test_scores_table.Constraints.Add( _
           New UniqueConstraint(studentid_testnumber_score_columns))
       " Make a relationship linking the
       " two tables" StudentId fields.
       scores_dataset.Relations.Add( _
           "Student Test Scores", _
           students_table.Columns("StudentId"), _
           test_scores_table.Columns("StudentId"))
       " Make some student data.
       students_table.Rows.Add(New Object() {"A", "A", 1})
       students_table.Rows.Add(New Object() {"B", "B", 2})
       students_table.Rows.Add(New Object() {"C", "C", 3})
       students_table.Rows.Add(New Object() {"D", "D", 4})
       " Make some random test scores.
       Dim score As New Random
       For id As Integer = 1 To 4
           For test_num As Integer = 1 To 10
               test_scores_table.Rows.Add( _
                   New Object() {id, test_num, score.Next(65, 100)})
           Next test_num
       Next id
       students_table.Columns("FirstName").ColumnMapping = MappingType.Element
       students_table.Columns("LastName").ColumnMapping = MappingType.Element
       students_table.Columns("StudentId").ColumnMapping = MappingType.Attribute
       Dim string_writer As New StringWriter()
       students_table.WriteXml(string_writer)
       Console.WriteLine(string_writer)
       grdScores.DataSource = scores_dataset
   End Sub

End Class <Global.Microsoft.VisualBasic.rupilerServices.DesignerGenerated()> _ Partial Public Class Form1

   Inherits System.Windows.Forms.Form
   "Form overrides dispose to clean up the component list.
   <System.Diagnostics.DebuggerNonUserCode()> _
   Protected Overloads Overrides Sub Dispose(ByVal disposing As Boolean)
       If disposing AndAlso components IsNot Nothing Then
           components.Dispose()
       End If
       MyBase.Dispose(disposing)
   End Sub
   "Required by the Windows Form Designer
   Private components As System.ruponentModel.IContainer
   "NOTE: The following procedure is required by the Windows Form Designer
   "It can be modified using the Windows Form Designer.  
   "Do not modify it using the code editor.
   <System.Diagnostics.DebuggerStepThrough()> _
   Private Sub InitializeComponent()
       Me.grdScores = New System.Windows.Forms.DataGrid
       CType(Me.grdScores, System.ruponentModel.ISupportInitialize).BeginInit()
       Me.SuspendLayout()
       "
       "grdScores
       "
       Me.grdScores.DataMember = ""
       Me.grdScores.Dock = System.Windows.Forms.DockStyle.Fill
       Me.grdScores.HeaderForeColor = System.Drawing.SystemColors.ControlText
       Me.grdScores.Location = New System.Drawing.Point(0, 0)
       Me.grdScores.Name = "grdScores"
       Me.grdScores.Size = New System.Drawing.Size(292, 273)
       Me.grdScores.TabIndex = 1
       "
       "Form1
       "
       Me.AutoScaleDimensions = New System.Drawing.SizeF(6.0!, 13.0!)
       Me.AutoScaleMode = System.Windows.Forms.AutoScaleMode.Font
       Me.ClientSize = New System.Drawing.Size(292, 273)
       Me.Controls.Add(Me.grdScores)
       Me.Name = "Form1"
       Me.Text = "MemoryDataSet"
       CType(Me.grdScores, System.ruponentModel.ISupportInitialize).EndInit()
       Me.ResumeLayout(False)
   End Sub
   Friend WithEvents grdScores As System.Windows.Forms.DataGrid

End Class</source>