⑴ vb.net 怎麼操作資料庫
如果樓主熟悉VB6，可以直接在項目中添加ADODB的Com引用，這樣你就可以像VB6那樣操作資料庫了！
另外
.NET
Framework中連接資料庫要用到ADO.NET。如果要操作Access資料庫，要用到System.Data.OleDb命名空間下的許多類。
比如按樓主所說，「我想在textbox1中顯示表一中【一些數據】欄位下的第一個內容」：
'首先導入命名空間
Imports
System.Data
Imports
System.Data.OleDb
'然後在某一個事件處理程序中寫：
Dim
conn
As
New
OleDbConnection("Provider=Microsoft.ACE.OLEDB.12.0;Data
Source=資料庫.accdb;Jet
OLEDB:Database
Password=MyDbPassword")
Dim
command
As
New
OleDbCommand("Select
*
From
數據表",
conn)
conn.Open()
'打開資料庫連接
Dim
reader
As
OleDbDataReader
=
command.ExecuteReader()
'執行SQL語句，返回OleDbDataReader
對象
Do
While
reader.Read()
'讀取一條數據
textbox1.Text
+=
reader("一些數據")
&
VbCrLf
Loop
reader.Close()
'關閉OleDbDataReader
conn.Close()
'關閉連接
⑵ vb.net 怎麼操作資料庫
Private stroledbprovider As String = "System.Data.OleDb" '大小寫 -------更改此處可連接不同類型的資料庫
'連接資料庫的信息，更改連接不同資料庫信息-------"Provider=Microsoft.Jet.OLEDB.4.0;Data Source=datapath;Persist Security Info=false"
Private stroledbconn As String = "Provider=SQLOLEDB;Data Source=localhost,10000;Initial Catalog=haofefe;user id=sa ; password=123" 'Integrated Security=SSPI"
'*********************************************************************
'************生成Dbproviderfactory,idbconnection,idbcommand,and idatareader********
Dim cnfactory As IDbConnection
Dim drcustsreader As IDataReader
Dim cmfactory As IDbCommand
Dim dpfactory As DbProviderFactory
Public login As Boolean = False
Private Sub createconn()
Try
dpfactory = System.Data.Common.DbProviderFactories.GetFactory(stroledbprovider)
cnfactory = dpfactory.CreateConnection
cnfactory.ConnectionString = stroledbconn
cmfactory = cnfactory.CreateCommand
cmfactory.CommandType = CommandType.Text
Catch ex As Exception
MsgBox(ex.ToString)
End Try
End Sub
'*********************************************************
'利用生成的連接
'****************查詢數據**************
Public Function getsources(ByVal strcomm As String) As DataTable
Dim i As Integer
Try
Call createconn() '調用生成實例
cmfactory.CommandText = strcomm
getsources = New DataTable
cnfactory.Open()
drcustsreader = cmfactory.ExecuteReader(CommandBehavior.KeyInfo)
With drcustsreader
For i = 0 To .FieldCount - 1
getsources.Columns.Add(.GetName(i))
Next
While .Read
Dim objcells(.FieldCount - 1) As Object
.GetValues(objcells)
getsources.Rows.Add(objcells)
End While
End With
drcustsreader.Close()
'getsources.Load(drcustsreader)
Return getsources
cnfactory.Close()
Catch ex As Exception
cnfactory.Close()
Return New Data.DataTable
MsgBox(ex.ToString)
End Try
End Function
'**********************************
'-------------------------------------------------------------------------------------------------------------
'*******************查看已連接信息******************
Public Sub connectionstatistics(ByVal conn As SqlConnection)
Dim htstats As Hashtable
Try
htstats = CType(conn.RetrieveStatistics, Hashtable)
Dim strstats As String
strstats = "ServerVersion: " + conn.ServerVersion.ToString + ControlChars.CrLf
Dim ostat As Object
Dim strstat As String
For Each ostat In htstats.Keys
strstat = ostat.ToString
If InStr(strstat, "Time") > 0 Then
strstats = strstats + strstat + "=" + Microsoft.VisualBasic.Format(CLng(htstats(strstat)) / 1000, "#,##0.000") + " secs" + vbCrLf
Else
strstats = strstats + strstat + "=" + htstats(strstat).ToString + ControlChars.Cr + ControlChars.Lf
End If
Next
MsgBox(strstats, MsgBoxStyle.Information, "Connection Statistics")
Catch ex As Exception
MsgBox(ex.ToString)
End Try
End Sub
⑶ 求一個用VB.net操作access資料庫的常式
Imports System
Imports System.Drawing
Imports System.ComponentModel
Imports System.Windows.Forms
Imports System.Data.OleDb
Imports System.Data
Public Class Form1
Inherits Form
Private components As System.ComponentModel.Container = Nothing
Private WithEvents lastrec As Button
Private WithEvents nextrec As Button
Private WithEvents previousrec As Button
Private WithEvents firstrec As Button
Private t_books As TextBox
Private t_nl As TextBox
Private t_xb As TextBox
Private t_xm As TextBox
Private t_id As TextBox
Private l_books As Label
Private l_nl As Label
Private l_xb As Label
Private l_xm As Label
Private l_id As Label
Private label1 As Label
Private myDataSet As DataSet
Private WithEvents button1 As Button
Private WithEvents button2 As Button
Private WithEvents button3 As Button
Private WithEvents button4 As Button
Private myBind As BindingManagerBase
Public Sub New ( )
MyBase.New ( )
GetConnected ( )
InitializeComponent ( )
End Sub
'清除在程序中使用過的資源
Protected Overloads Overrides Sub Dispose (ByVal disposing As Boolean)
If disposing Then
If Not (components Is Nothing) Then
components.Dispose ( )
End If
End If
MyBase.Dispose ( disposing )
End Sub
Public Sub GetConnected ( )
'創建一個數據連接
Dim strCon As String = " Provider = Microsoft.Jet.OLEDB.4.0 ;
Data Source = db.mdb "
Dim myConn As OleDbConnection = New OleDbConnection ( )
myConn.ConnectionString = strCon
Dim strCom As String = " SELECT * FROM person "
'創建一個 DataSet
myDataSet = New DataSet ( )
myConn.Open ( )
'通過OleDbDataAdapter對象得到一個數據集
Dim myCommand As OleDbDataAdapter = New OleDbDataAdapter
( strCom , myConn )
'把Dataset綁定books數據表
myCommand.Fill ( myDataSet , "person" )
'關閉此數據連接
myConn.Close ( )
End Sub
'插入數據記錄操作代碼
Private Sub button2_Click (ByVal sender As Object , _
ByVal e As System.EventArgs) Handles button2.Click
'判斷所有欄位是否添完，添完則執行，反之彈出提示
If ( t_id.Text <> "" And t_xm.Text <> ""
And t_xb.Text <> "" And t_nl.Text <> ""
And t_books.Text <> "" ) Then
Dim myConn1 As String = " Provider = Microsoft.Jet.OLEDB.4.0 ;
Data Source = db.mdb"
Dim myConn As OleDbConnection = New OleDbConnection ( myConn1 )
myConn.Open ( )
Dim strInsert As String = " INSERT INTO person ( id , xm , xb , nl
, zip ) VALUES ( " & _
t_id.Text + " , '" & _
t_xm.Text + "' , '" & _
t_xb.Text + "' , " & _
t_nl.Text + " , " & _
t_books.Text + ")"
Dim inst As OleDbCommand = New OleDbCommand ( strInsert , myConn )
inst.ExecuteNonQuery ( )
myConn.Close ( )
myDataSet.Tables ( "person" ).Rows ( myBind.Position ).BeginEdit ( )
myDataSet.Tables ( "person" ).Rows ( myBind.Position ).EndEdit ( )
myDataSet.Tables ( "person" ).AcceptChanges ( )
Else
MessageBox.Show ( "必須填滿所有欄位值！" , "錯誤！" )
End If
End Sub
⑷ vb.net資料庫操作
參考一下下面這段代碼就可以了。
Imports System.Data
'引入資料庫操作類命名空間
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對象
Public mytable As Data.DataTable
'建立表單對象
Public myrow As Data.DataRow
'建立數據行對象
Public rownumber As Integer
'定義一個整型變數來存放當前行數
Public SearchSQL As String
Public cmd As OleDbCommandBuilder
'======================================================
#Region " Windows 窗體設計器生成的代碼 "
#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 '設置信息為只讀
Dim tablename As String = "student_Info "
SearchSQL = "select * from student_Info "
ExecuteSQL(SearchSQL, tablename) '打開資料庫
ShowData() '顯示記錄
End Sub
Private Sub ShowData()
'在窗口中的textbox中顯示數據
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
'指向第一條數據
rownumber = 0
ShowData()
End Sub
Private Sub BtPrev_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles BtPrev.Click
'指向上一條數據
BtNext.Enabled = True
rownumber = rownumber - 1
If rownumber < 0 Then
rownumber = 0 '如果到達記錄的首部，行號設為零
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
'指向上一條數據
BtPrev.Enabled = True
rownumber = rownumber + 1
If rownumber > mytable.Rows.Count - 1 Then
rownumber = mytable.Rows.Count - 1 '判斷是否到達最後一條數據
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
'指向最後一條數據
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( "確定要刪除改記錄嗎？ ", MsgBoxStyle.OKCancel + vbExclamation, "警告 ") = MsgBoxResult.OK Then
cmd = New OleDbCommandBuilder(ADOcmd)
'使用自動生成的SQL語句
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 '關鍵欄位只讀
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( "請輸入姓名！ ", vbOKOnly + vbExclamation, "警告 ")
TxtName.Focus()
Exit Sub
End If
If Not Testtxt(ComboSex.Text) Then
MsgBox( "請選擇性別！ ", vbOKOnly + vbExclamation, "警告 ")
ComboSex.Focus()
Exit Sub
End If
If Not Testtxt(TxtClassno.Text) Then
MsgBox( "請選擇班號！ ", vbOKOnly + vbExclamation, "警告 ")
TxtClassno.Focus()
Exit Sub
End If
If Not Testtxt(TxtTel.Text) Then
MsgBox( "請輸入聯系電話！ ", vbOKOnly + vbExclamation, "警告 ")
TxtTel.Focus()
Exit Sub
End If
If Not Testtxt(TxtAddress.Text) Then
MsgBox( "請輸入家庭住址！ ", vbOKOnly + vbExclamation, "警告 ")
TxtAddress.Focus()
Exit Sub
End If
If Not IsNumeric(Trim(TxtSID.Text)) Then
MsgBox( "請輸入數字學號！ ", vbOKOnly + vbExclamation, "警告 ")
Exit Sub
TxtSID.Focus()
End If
If Not IsDate(TxtBornDate.Text) Then
MsgBox( "出生時間應輸入日期格式（yyyy-mm-dd）！ ", vbOKOnly + vbExclamation, "警告 ")
Exit Sub
TxtBornDate.Focus()
End If
If Not IsDate(TxtRuDate.Text) Then
MsgBox( "入校時間應輸入日期格式（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)
'使用自動生成的SQL語句
ADOcmd.Update(ds, "student_Info ")
'對資料庫進行更新
MsgBox( "修改學籍信息成功！ ", 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對象
'資料庫查詢函數
ADOcmd = New OleDbDataAdapter(SQL, "Provider=Microsoft.Jet.OLEDB.4.0;Data Source=c:\student.mdb ")
'建立ADODataSetCommand對象
ADOcmd.Fill(ds, table) '取得表單
mytable = ds.Tables.Item(0) '取得名為table的表
rownumber = 0 '設置為第一行
myrow = mytable.Rows.Item(rownumber)
'取得第一行數據
Catch
MsgBox(Err.Description)
End Try
End Function
End Class
⑸ 用vb.net 怎樣建立一個mdb資料庫及一張表
首先在項目的VB.NET界面，使用菜單【項目】--【添加引用】--【COM】
選擇 Microsoft ADO Ext. 2.x for DDL and Security
然後單擊【確定】，完成引用。
完整代碼如下：
ImportsADOX
PublicClassForm1
PrivateSubButton1_Click(ByValsenderAsSystem.Object,ByValeAsSystem.EventArgs)HandlesButton1.Click
'創建空的access資料庫文件--資料庫文件.mdb，密碼為123
DimMycatAsCatalog=NewCatalog()
Mycat.Create("Provider=Microsoft.Jet.OLEDB.4.0;JetOLEDB:EngineType=5;DataSource=資料庫文件.mdb;JetOLEDB:DatabasePassword=123")
'以下代碼創建一個名為「實驗數據表」
DimMyTableAsADOX.Table=NewADOX.Table'定義新表
MyTable.Name="實驗數據表"'表命名
'給表「實驗數據表」創建一個字元串欄位，欄位名「姓名」
MyTable.Columns.Append("姓名",,ADOX.DataTypeEnum.adWChar)
'給表「實驗數據表」創建一個整數欄位，欄位名「學號」
MyTable.Columns.Append("學號",ADOX.DataTypeEnum.adInteger)'追加一個數字型欄位
'給欄位「學號」創建一個主鍵「PimaryKey_Field」
MyTable.Keys.Append("學號",ADOX.KeyTypeEnum.adKeyPrimary,"學號")
Mycat.Tables.Append(MyTable)'把所有的新欄位追加到表
MyTable=Nothing
Mycat=Nothing
EndSub
EndClass