в 16:40, 26 мая 2010

2010-05-26T16:40:06Z

Admin: 1 версия

2010-05-26T12:44:43Z

1 версия

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==Get Colunm Data type==

<source lang="vbnet">
Imports System
Imports System.Data
Imports System.Data.SqlClient

public class MainClass
Shared Sub Main()
Dim thisConnection As New SqlConnection("server=(local)\SQLEXPRESS;" & _
"integrated security=sspi;database=MyDatabase")
"Sql Query 1
Dim sql As String ="SELECT ID, FirstName, LastName FROM Employee; "
"Create Command object
Dim thisCommand As New SqlCommand _
(sql, thisConnection)
Try
" Open Connection
thisConnection.Open()
Console.WriteLine("Connection Opened")
" Execute Query
Dim thisReader As SqlDataReader = thisCommand.ExecuteReader()
" Get column data types
Console.WriteLine("Data types: {0} | {1}", _
thisReader.GetDataTypeName(0).PadLeft(13), _
thisReader.GetDataTypeName(1))

"Close DataReader
thisReader.Close()
Catch ex As SqlException
" Display error
Console.WriteLine("Error: " & ex.ToString())
Finally
" Close Connection
thisConnection.Close()
Console.WriteLine("Connection Closed")
End Try
End Sub
End Class

</source>

==Get table column Name==

<source lang="vbnet">
Imports System
Imports System.Collections
Imports System.Data
Imports System.IO
Imports System.Xml.Serialization
Imports System.Windows.Forms
Imports System.Data.SqlClient

Public Class MainClass
Shared Dim WithEvents con As SqlConnection
Shared Sub Main()
con = New SqlConnection("Server=(local)\SQLEXPRESS;Initial Catalog=MyDatabase;Integrated Security=SSPI")
Dim str As String = "SELECT ID, FirstName, LastName FROM Employee"
Dim cmd As New SqlCommand(str, con)
Dim da As New SqlDataAdapter(cmd)
Dim ds As New DataSet()
da.Fill(ds, "Employee")
" Display the column names
Dim dc As DataColumn
For Each dc In ds.Tables(0).Columns
Console.Write("{0,15}", dc.ColumnName)
Next
" Add a newline after the column headings
Console.Write(vbCrLf)
" Display the data for each row. Loop through the rows first.
Dim dr As DataRow
For Each dr In ds.Tables(0).Rows
" Then loop through the columns for the current row.
Dim i As Integer
For i = 1 To ds.Tables(0).Columns.Count
Console.Write("{0,15}", dr(i - 1))
Next i
" Add a line break after every row
Console.Write(vbCrLf)
Next
End Sub
End Class

</source>

==Read Table data by Table Column Name==

<source lang="vbnet">
Imports System
Imports System.Data
Imports System.Data.OleDb
Imports System.Data.SqlClient
Imports System.Collections
Imports System.Windows.Forms
Imports System.Resources
Public Class MainClass
Shared Sub Main()
"Declare variables and objects
Dim strConnectionString As String = _
"Provider=Microsoft.Jet.OLEDB.4.0;" & _
"Data Source=Employee.mdb;"
Dim objConnection As New OleDbConnection(strConnectionString)
Dim strSQL As String = _
"SELECT FirstName, LastName FROM Employee"
Dim objCommand As New OleDbCommand(strSQL, objConnection)
Dim objDataAdapter As New OleDbDataAdapter(objCommand)
Dim objDataTable As New Data.DataTable("Employee")
Dim objDataRow As DataRow
Try
"Open the database connection
objConnection.Open()
"Fill the DataTable object
objDataAdapter.Fill(objDataTable)
"Load the list box on the form
For Each objDataRow In objDataTable.Rows
Console.WriteLine(objDataRow.Item("FirstName") & " " & _
objDataRow.Item("LastName"))
Next
Catch OleDbExceptionErr As OleDbException
"Write the exception
Console.WriteLine(OleDbExceptionErr.Message)
Catch InvalidOperationExceptionErr As InvalidOperationException
"Write the exception
Console.WriteLine(InvalidOperationExceptionErr.Message)
End Try
"Close the database connection
objConnection.Close()
"Clean up
objDataRow = Nothing
objDataTable.Dispose()
objDataTable = Nothing
objDataAdapter.Dispose()
objDataAdapter = Nothing
objCommand.Dispose()
objCommand = Nothing
objConnection.Dispose()
objConnection = Nothing
End Sub
End Class

</source>
<A href="http://www.vbex.ru/Code/VBDownload/Employee.zip">Employee.zip( 7 k)</a>

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VB.Net/Database ADO.net/Table Column - История изменений

в 16:40, 26 мая 2010

Admin: 1 версия