一個經典的ADO.NET入門例子
2020-01-18 01:55:45
供稿：網友
眾所周知，ADO.NET相對于ADO的最大優勢在于對于數據的更新修改可以在與數據源完全斷開聯系的情況下進行，然后再把數據更新情況傳回到
數據源。這樣大大減少了連接過多對于數據庫服務器資源的占用。下面是我在《ADO.NET實用指南》這本書上看到的一個例子，比較清楚的講解
了ADO.NET的使用方法。
Imports System.Data.SqlClient
Imports System.Data
Imports System.Data.Common
Public Class Form1
Inherits System.Windows.Forms.Form
Private Sub Button1_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button1.Click
Dim conn As New SqlConnection("data source=localhost;initial catalog=StudentCourse;" & _
"User ID=;Password=;")
Dim ds As New DataSet
Try
conn.Open() '在形成SqlDataAdapter前打開conn
Dim daAuthors As New SqlDataAdapter("Select * From SC", conn)
Dim bldr As New SqlCommandBuilder(daAuthors)
daAuthors.Fill(ds,"SC")
conn.Close() '在填充完ds后關閉連接，接著對ds進行操作
Dim tbl As New DataTable
tbl = ds.Tables("SC")
Dim rowVals(3) As Object
rowVals(0) = "5"
rowVals(1) = "00003"
rowVals(2) = "0001"
rowVals(3) = 99
Dim insertedRow As DataRow
insertedRow = tbl.Rows.Add(rowVals) '添加一行
tbl.Rows(0).Delete() '刪除一行
tbl.Rows(1).BeginEdit()
tbl.Rows(1)("score") = 89 '修改一行
tbl.Rows(1).EndEdit()
conn.Open()
daAuthors.Update(ds.Tables("SC")) '須將結果傳回數據源時打開連接，update
conn.Close()
Catch ex As Exception
MessageBox.Show(ex.Message)
End Try
End Sub
End Class
