数据库实例(VB.NET)

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
      Dim sql As String = "SELECT * FROM Employee "

      Dim insertSql As String = "INSERT INTO Employee " & _
         "(ID, FirstName, LastName)VALUES" & _
         "(@ID, @FirstName, @LastName)"

      Try
         ' Create Data Adapter
         Dim da As New SqlDataAdapter
         da.SelectCommand = New SqlCommand(sql, thisConnection)

         ' Create and fill Dataset
         Dim ds As New DataSet
         da.Fill(ds, "Employee")

         ' Get the Data Table
         Dim dt As DataTable = ds.Tables("Employee")

         ' Display Rows Before Changed
         Console.WriteLine("Before altering the dataset")
         For Each row As DataRow In dt.Rows
            Console.WriteLine("{0} | {1} | {2}", _
               row("ID").ToString().PadRight(10), _
               row("FirstName").ToString().PadRight(10), _
               row("LastName"))
         Next

         ' Add A Row
         Dim newRow As DataRow = dt.NewRow()
         newRow("FirstName") = "Edna"
         newRow("LastName") = "Everage"
         newRow("ID") = "2"
         dt.Rows.Add(newRow)

         ' Display Rows After Alteration
         Console.WriteLine("=========")
         Console.WriteLine("After altering the dataset")
         For Each row As DataRow In dt.Rows
            Console.WriteLine("{0} | {1} | {2}", _
               row("ID").ToString().PadRight(10), _
               row("FirstName").ToString().PadRight(10), _
               row("LastName"))
         Next

         ' Insert employees
         ' 1. Create command
         Dim insertCmd As New SqlCommand(insertSql, thisConnection)

         ' 2. Map parameters
         insertCmd.Parameters.Add("@FirstName", _
            SqlDbType.NVarChar, 10, "FirstName")
         insertCmd.Parameters.Add("@LastName", _
            SqlDbType.NVarChar, 20, "LastName")
         insertCmd.Parameters.Add("@ID", _
            SqlDbType.Int, 15, "ID")

         ' 3. Insert employees
         da.InsertCommand = insertCmd
         da.Update(ds, "Employee")
      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