用MyDataBase更新DataGridView上變動的資料
Introduction
這陣子碰到許多網友再問如何用Update更新資料到資料庫。為回答網友的提問，用MyDataBase偷懶的寫了一個範例程式。主要功能是把DataGridView上更動的資料寫回資料庫。在此隨手記錄一下。
欲看Update的寫法可參考MyDataBase原始碼。需注意的是，MyDataBase內部所用的Command是用自動產生的，在效能上會較直接指定Command來得差，參考看看就好。
範例
VB.NET
Public Class Form1
Dim dbA As New UseDB.AccessDB("A.mdb")
Dim dbB As New UseDB.AccessDB("B.mdb")
Private Sub Form1_Load(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles MyBase.Load
LoadADB()
LoadBDB()
End Sub
Private Sub Button2_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button2.Click
WriteToDB(dbA)
End Sub
Private Sub Button3_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button3.Click
LoadADB()
End Sub
Private Sub Button1_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button1.Click
WriteToDB(dbB)
End Sub
Private Sub Button4_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button4.Click
LoadBDB()
End Sub
Private Sub LoadADB()
Me.DataGridView1.DataSource = dbA.GetDataTable("Select * from test")
End Sub
Private Sub LoadBDB()
Me.DataGridView2.DataSource = dbB.GetDataTable("Select * from test")
End Sub
Private Sub WriteToDB(ByVal db As UseDB.AccessDB)
Dim table As DataTable = DirectCast(Me.DataGridView1.DataSource, DataTable)
Dim changeTable As DataTable = table.GetChanges
If changeTable Is Nothing Then
MsgBox("Without Change")
Return
End If
db.WriteDataFromDataTable(changeTable, "Test")
table.AcceptChanges()
If db Is dbA Then
LoadADB()
Else
LoadBDB()
End If
End SubEnd Class