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關(guān)于vb.net上數(shù)據(jù)庫(kù)的使用問(wèn)題
你把數(shù)據(jù)庫(kù)中的數(shù)據(jù)查詢出來(lái)保存在DataSet 中
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DataSet 是脫機(jī)的數(shù)據(jù)集,也即與數(shù)據(jù)庫(kù)斷開(kāi)的數(shù)據(jù)集
把DataSet綁定到GridView上,這時(shí)候你在GridView上的操作就都是與數(shù)據(jù)庫(kù)斷開(kāi)的
vb.net如何定義一維和多維數(shù)組
用一個(gè)帶括號(hào)的變量名來(lái)定義一維數(shù)組和多維數(shù)組如dim a(5) as integer '定義了1個(gè)1維、6個(gè)元素?cái)?shù)組dim a(5,5) as integer '定義了1個(gè)2維、36個(gè)元素的數(shù)組
vb.net 數(shù)組的定義方法
1、vb.net的
數(shù)組定義與變量定義差不多。可以用
dim
來(lái)定義
比如:
dim
a(100)
as
integer。
也可以不定義下標(biāo)
在程序中
用
redim
來(lái)定義。
如:
dim
a()
as
integer
'
'
redim
a(100)
2、vb.net中定義數(shù)組可以直接賦值。
如:
dim
a()
as
integer
={1,
2,
3,4}
vb.net數(shù)據(jù)庫(kù)操作
參考一下下面這段代碼就可以了。
Imports System.Data
'引入數(shù)據(jù)庫(kù)操作類命名空間
Imports System.Data.OleDb
'引入ADO.NET操作命名空間
Public Class FrmModifystInfo
Inherits System.Windows.Forms.Form
Public ADOcmd As OleDbDataAdapter
Public ds As DataSet = New DataSet()
'建立DataSet對(duì)象
Public mytable As Data.DataTable
'建立表單對(duì)象
Public myrow As Data.DataRow
'建立數(shù)據(jù)行對(duì)象
Public rownumber As Integer
'定義一個(gè)整型變量來(lái)存放當(dāng)前行數(shù)
Public SearchSQL As String
Public cmd As OleDbCommandBuilder
'======================================================
#Region " Windows 窗體設(shè)計(jì)器生成的代碼 "
#End Region
'======================================================
Private Sub FrmModifystInfo_Load(ByVal sender As Object, ByVal e As System.EventArgs) Handles MyBase.Load
'窗體的載入
TxtSID.Enabled = False
TxtName.Enabled = False
ComboSex.Enabled = False
TxtBornDate.Enabled = False
TxtClassno.Enabled = False
TxtRuDate.Enabled = False
TxtTel.Enabled = False
TxtAddress.Enabled = False
TxtComment.Enabled = False '設(shè)置信息為只讀
Dim tablename As String = "student_Info "
SearchSQL = "select * from student_Info "
ExecuteSQL(SearchSQL, tablename) '打開(kāi)數(shù)據(jù)庫(kù)
ShowData() '顯示記錄
End Sub
Private Sub ShowData()
'在窗口中的textbox中顯示數(shù)據(jù)
myrow = mytable.Rows.Item(rownumber)
TxtSID.Text = myrow.Item(0).ToString
TxtName.Text = myrow.Item(1).ToString
ComboSex.Text = myrow.Item(2).ToString
TxtBornDate.Text = Format(myrow.Item(3), "yyyy-MM-dd ")
TxtClassno.Text = myrow.Item(4).ToString
TxtTel.Text = myrow.Item(5).ToString
TxtRuDate.Text = Format(CDate(myrow.Item(6)), "yyyy-MM-dd ")
TxtAddress.Text = myrow.Item(7).ToString
TxtComment.Text = myrow.Item(8).ToString
End Sub
Private Sub BtFirst_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles BtFirst.Click
'指向第一條數(shù)據(jù)
rownumber = 0
ShowData()
End Sub
Private Sub BtPrev_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles BtPrev.Click
'指向上一條數(shù)據(jù)
BtNext.Enabled = True
rownumber = rownumber - 1
If rownumber 0 Then
rownumber = 0 '如果到達(dá)記錄的首部,行號(hào)設(shè)為零
BtPrev.Enabled = False
End If
ShowData()
End Sub
Private Sub BtNext_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles BtNext.Click
'指向上一條數(shù)據(jù)
BtPrev.Enabled = True
rownumber = rownumber + 1
If rownumber mytable.Rows.Count - 1 Then
rownumber = mytable.Rows.Count - 1 '判斷是否到達(dá)最后一條數(shù)據(jù)
BtNext.Enabled = False
End If
ShowData()
End Sub
Private Sub BtLast_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles BtLast.Click
'指向最后一條數(shù)據(jù)
rownumber = mytable.Rows.Count - 1
ShowData()
End Sub
Private Sub BtDelete_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles BtDelete.Click
mytable.Rows.Item(rownumber).Delete() '刪除記錄
If MsgBox( "確定要?jiǎng)h除改記錄嗎? ", MsgBoxStyle.OKCancel + vbExclamation, "警告 ") = MsgBoxResult.OK Then
cmd = New OleDbCommandBuilder(ADOcmd)
'使用自動(dòng)生成的SQL語(yǔ)句
ADOcmd.Update(ds, "student_Info ")
BtNext.PerformClick()
End If
End Sub
Private Sub BtModify_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles BtModify.Click
TxtSID.Enabled = False '關(guān)鍵字段只讀
TxtName.Enabled = True '可讀寫
ComboSex.Enabled = True
TxtBornDate.Enabled = True
TxtClassno.Enabled = True
TxtRuDate.Enabled = True
TxtTel.Enabled = True
TxtAddress.Enabled = True
TxtComment.Enabled = True
End Sub
Private Sub BtUpdate_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles BtUpdate.Click
If Not Testtxt(TxtName.Text) Then
MsgBox( "請(qǐng)輸入姓名! ", vbOKOnly + vbExclamation, "警告 ")
TxtName.Focus()
Exit Sub
End If
If Not Testtxt(ComboSex.Text) Then
MsgBox( "請(qǐng)選擇性別! ", vbOKOnly + vbExclamation, "警告 ")
ComboSex.Focus()
Exit Sub
End If
If Not Testtxt(TxtClassno.Text) Then
MsgBox( "請(qǐng)選擇班號(hào)! ", vbOKOnly + vbExclamation, "警告 ")
TxtClassno.Focus()
Exit Sub
End If
If Not Testtxt(TxtTel.Text) Then
MsgBox( "請(qǐng)輸入聯(lián)系電話! ", vbOKOnly + vbExclamation, "警告 ")
TxtTel.Focus()
Exit Sub
End If
If Not Testtxt(TxtAddress.Text) Then
MsgBox( "請(qǐng)輸入家庭住址! ", vbOKOnly + vbExclamation, "警告 ")
TxtAddress.Focus()
Exit Sub
End If
If Not IsNumeric(Trim(TxtSID.Text)) Then
MsgBox( "請(qǐng)輸入數(shù)字學(xué)號(hào)! ", vbOKOnly + vbExclamation, "警告 ")
Exit Sub
TxtSID.Focus()
End If
If Not IsDate(TxtBornDate.Text) Then
MsgBox( "出生時(shí)間應(yīng)輸入日期格式(yyyy-mm-dd)! ", vbOKOnly + vbExclamation, "警告 ")
Exit Sub
TxtBornDate.Focus()
End If
If Not IsDate(TxtRuDate.Text) Then
MsgBox( "入校時(shí)間應(yīng)輸入日期格式(yyyy-mm-dd)! ", vbOKOnly + vbExclamation, "警告 ")
TxtRuDate.Focus()
Exit Sub
End If
myrow.Item(0) = Trim(TxtSID.Text)
myrow.Item(1) = Trim(TxtName.Text)
myrow.Item(2) = Trim(ComboSex.Text)
myrow.Item(3) = Trim(TxtBornDate.Text)
myrow.Item(4) = Trim(TxtClassno.Text)
myrow.Item(5) = Trim(TxtTel.Text)
myrow.Item(6) = Trim(TxtRuDate.Text)
myrow.Item(7) = Trim(TxtAddress.Text)
myrow.Item(8) = Trim(TxtComment.Text)
mytable.GetChanges()
cmd = New OleDbCommandBuilder(ADOcmd)
'使用自動(dòng)生成的SQL語(yǔ)句
ADOcmd.Update(ds, "student_Info ")
'對(duì)數(shù)據(jù)庫(kù)進(jìn)行更新
MsgBox( "修改學(xué)籍信息成功! ", vbOKOnly + vbExclamation, "警告 ")
TxtName.Enabled = False
ComboSex.Enabled = False
TxtBornDate.Enabled = False
TxtClassno.Enabled = False
TxtRuDate.Enabled = False
TxtTel.Enabled = False
TxtAddress.Enabled = False
TxtComment.Enabled = False '重新設(shè)置信息為只讀
End Sub
Private Sub BtCancel_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles BtCancel.Click
TxtSID.Enabled = False
TxtName.Enabled = False
ComboSex.Enabled = False
TxtBornDate.Enabled = False
TxtClassno.Enabled = False
TxtRuDate.Enabled = False
TxtTel.Enabled = False
TxtAddress.Enabled = False
TxtComment.Enabled = False
End Sub
Public Function ExecuteSQL(ByVal SQL As String, ByVal table As String)
Try
'建立ADODataSetCommand對(duì)象
'數(shù)據(jù)庫(kù)查詢函數(shù)
ADOcmd = New OleDbDataAdapter(SQL, "Provider=Microsoft.Jet.OLEDB.4.0;Data Source=c:\student.mdb ")
'建立ADODataSetCommand對(duì)象
ADOcmd.Fill(ds, table) '取得表單
mytable = ds.Tables.Item(0) '取得名為table的表
rownumber = 0 '設(shè)置為第一行
myrow = mytable.Rows.Item(rownumber)
'取得第一行數(shù)據(jù)
Catch
MsgBox(Err.Description)
End Try
End Function
End Class
在 Visual Studio 2005中用vb.net怎么定義內(nèi)存中的數(shù)據(jù)庫(kù)dataset
dataset類在System.Data命名空間下
所以應(yīng)該引用:
imports System.Data
分享題目:vb.net定義數(shù)據(jù)集 vbnet數(shù)據(jù)庫(kù)編程例子
標(biāo)題鏈接:http://fisionsoft.com.cn/article/doopopj.html