VB.Net/Database ADO.net/OleDb Table Schema
Use OleDb to get the data table schema
<source lang="vbnet"> Imports System Imports System.Collections Imports System.Data Imports System.IO Imports System.Xml.Serialization Imports System.Xml Imports System.Windows.Forms Imports System.Data.SqlClient Imports System.Data.OleDb Public Class MainClass
Shared Sub Main()
Dim form1 As Form = New Form1
Application.Run(form1)
End Sub
End Class
Public Class Form1
Inherits System.Windows.Forms.Form
- Region " Windows Form Designer generated code "
Public Sub New()
MyBase.New()
"This call is required by the Windows Form Designer.
InitializeComponent()
"Add any initialization after the InitializeComponent() call
End Sub
"Form overrides dispose to clean up the component list.
Protected Overloads Overrides Sub Dispose(ByVal disposing As Boolean)
If disposing Then
If Not (components Is Nothing) Then
components.Dispose()
End If
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.
Friend WithEvents Button1 As System.Windows.Forms.Button
Friend WithEvents SchemaTableList As System.Windows.Forms.ListView
<System.Diagnostics.DebuggerStepThrough()> Private Sub InitializeComponent()
Me.Button1 = New System.Windows.Forms.Button()
Me.SchemaTableList = New System.Windows.Forms.ListView()
Me.SuspendLayout()
"
"Button1
"
Me.Button1.Location = New System.Drawing.Point(808, 520)
Me.Button1.Name = "Button1"
Me.Button1.Size = New System.Drawing.Size(136, 23)
Me.Button1.TabIndex = 3
Me.Button1.Text = "Read Schema"
"
"SchemaTableList
"
Me.SchemaTableList.Dock = System.Windows.Forms.DockStyle.Top
Me.SchemaTableList.Name = "SchemaTableList"
Me.SchemaTableList.Size = New System.Drawing.Size(952, 512)
Me.SchemaTableList.TabIndex = 2
"
"Form1
"
Me.AutoScaleBaseSize = New System.Drawing.Size(6, 15)
Me.ClientSize = New System.Drawing.Size(952, 552)
Me.Controls.AddRange(New System.Windows.Forms.Control() {Me.Button1, Me.SchemaTableList})
Me.Name = "Form1"
Me.Text = "Form1"
Me.ResumeLayout(False)
End Sub
- End Region
Private Sub Button1_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button1.Click
Dim conn As OleDbConnection = New OleDbConnection _
("Provider=SQLOLEDB;Data Source=(local)\SQLEXPRESS;Initial Catalog=MyDatabase;uid=sa;pwd=vbex;")
" Retrieving schema for columns from a single table
Dim cmd As OleDbCommand = New OleDbCommand("Employee", conn)
cmd.rumandType = CommandType.TableDirect
" Retrieve schema only
conn.Open()
Dim reader As OleDbDataReader = cmd.ExecuteReader(CommandBehavior.SchemaOnly)
" Get references to schema information
Dim SchemaTable As DataTable = reader.GetSchemaTable()
" Close and release the connection before processing results
reader.Close()
conn.Close()
" Display schema table column headers
Dim col As DataColumn
SchemaTableList.View = View.Details
For Each col In SchemaTable.Columns
SchemaTableList.Columns.Add(col.ColumnName, 100, HorizontalAlignment.Left)
Next
" Display schema
Dim row As DataRow
Dim ColCount As Integer = SchemaTable.Columns.Count
For Each row In SchemaTable.Rows
Dim OrderDetails(ColCount) As String
Dim ColIdx As Integer
For ColIdx = 0 To ColCount - 1
OrderDetails(ColIdx) = Convert.ToString(row(ColIdx))
Next
Dim NewItem As ListViewItem = New ListViewItem(OrderDetails)
SchemaTableList.Items.Add(NewItem)
Next
End Sub
End Class
</source>
Use OleDb to get the data table schema and display in a DataGrid
<source lang="vbnet"> Imports System Imports System.Collections Imports System.Data Imports System.IO Imports System.Xml.Serialization Imports System.Xml Imports System.Windows.Forms Imports System.Data.SqlClient Imports System.Data.OleDb Public Class MainClass
Shared Sub Main()
Dim form1 As Form = New Form1
Application.Run(form1)
End Sub
End Class
Public Class Form1
Inherits System.Windows.Forms.Form
- Region " Windows Form Designer generated code "
Public Sub New()
MyBase.New()
"This call is required by the Windows Form Designer.
InitializeComponent()
"Add any initialization after the InitializeComponent() call
End Sub
"Form overrides dispose to clean up the component list.
Protected Overloads Overrides Sub Dispose(ByVal disposing As Boolean)
If disposing Then
If Not (components Is Nothing) Then
components.Dispose()
End If
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.
Friend WithEvents Button1 As System.Windows.Forms.Button
Friend WithEvents SchemaTableList As System.Windows.Forms.ListView
<System.Diagnostics.DebuggerStepThrough()> Private Sub InitializeComponent()
Me.Button1 = New System.Windows.Forms.Button()
Me.SchemaTableList = New System.Windows.Forms.ListView()
Me.SuspendLayout()
"
"Button1
"
Me.Button1.Location = New System.Drawing.Point(808, 520)
Me.Button1.Name = "Button1"
Me.Button1.Size = New System.Drawing.Size(136, 23)
Me.Button1.TabIndex = 3
Me.Button1.Text = "Read Schema"
"
"SchemaTableList
"
Me.SchemaTableList.Dock = System.Windows.Forms.DockStyle.Top
Me.SchemaTableList.Name = "SchemaTableList"
Me.SchemaTableList.Size = New System.Drawing.Size(952, 512)
Me.SchemaTableList.TabIndex = 2
"
"Form1
"
Me.AutoScaleBaseSize = New System.Drawing.Size(6, 15)
Me.ClientSize = New System.Drawing.Size(952, 552)
Me.Controls.AddRange(New System.Windows.Forms.Control() {Me.Button1, Me.SchemaTableList})
Me.Name = "Form1"
Me.Text = "Form1"
Me.ResumeLayout(False)
End Sub
- End Region
Private Sub Button1_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button1.Click
Dim conn As OleDbConnection = New OleDbConnection _
("Provider=SQLOLEDB;Data Source=(local)\SQLEXPRESS;Initial Catalog=MyDatabase;uid=sa;pwd=vbex;")
" Retrieving schema for columns from a single table
Dim cmd As OleDbCommand = New OleDbCommand("Employee", conn)
cmd.rumandType = CommandType.TableDirect
" Retrieve schema only
conn.Open()
Dim reader As OleDbDataReader = cmd.ExecuteReader(CommandBehavior.SchemaOnly)
" Get references to schema information
Dim SchemaTable As DataTable = reader.GetSchemaTable()
" Close and release the connection before processing results
reader.Close()
conn.Close()
" Display schema table column headers
Dim col As DataColumn
SchemaTableList.View = View.Details
For Each col In SchemaTable.Columns
SchemaTableList.Columns.Add(col.ColumnName, 100, HorizontalAlignment.Left)
Next
" Display schema
Dim row As DataRow
Dim ColCount As Integer = SchemaTable.Columns.Count
For Each row In SchemaTable.Rows
Dim OrderDetails(ColCount) As String
Dim ColIdx As Integer
For ColIdx = 0 To ColCount - 1
OrderDetails(ColIdx) = Convert.ToString(row(ColIdx))
Next
Dim NewItem As ListViewItem = New ListViewItem(OrderDetails)
SchemaTableList.Items.Add(NewItem)
Next
End Sub
End Class
</source>
