select
站在用戶的角度思考問(wèn)題，與客戶深入溝通，找到湖南網(wǎng)站設(shè)計(jì)與湖南網(wǎng)站推廣的解決方案，憑借多年的經(jīng)驗(yàn)，讓設(shè)計(jì)與互聯(lián)網(wǎng)技術(shù)結(jié)合，創(chuàng)造個(gè)性化、用戶體驗(yàn)好的作品，建站類型包括：網(wǎng)站制作、網(wǎng)站建設(shè)、企業(yè)官網(wǎng)、英文網(wǎng)站、手機(jī)端網(wǎng)站、網(wǎng)站推廣、國(guó)際域名空間、網(wǎng)頁(yè)空間、企業(yè)郵箱。業(yè)務(wù)覆蓋湖南地區(qū)。
*
from
XXX
如果數(shù)據(jù)量少還可以，如果數(shù)據(jù)量一大，需要從適配器在讀取到Dataset中，這個(gè)是相當(dāng)耗時(shí)的。
其實(shí)，有一些程序可以采用
分段讀取，多次讀取。
像這樣的寫法，更新一條數(shù)據(jù)，就需要在重新讀取所有的數(shù)據(jù)。。耗費(fèi)太大資源和貸款。。
客戶端也會(huì)導(dǎo)致很慢甚至讀取數(shù)據(jù)假死。。
-----------------------------
最好的方式不管你用DataRead還是什么，這些都根本解決不了這些問(wèn)題。
你需要做的就是
如何高效讀取/處理數(shù)據(jù)。
BS
結(jié)構(gòu)，可以采用異步加載數(shù)據(jù)和處理數(shù)據(jù)
CS結(jié)構(gòu)
異步加載和分段讀取數(shù)據(jù)。而不是一下子就把所有數(shù)據(jù)加載處理。這樣的話，CPU和內(nèi)存占用率就會(huì)抬高。。。。
---------------------------------
之前公司采用的方式就是這樣的，DataSet和Fill
后來(lái)發(fā)現(xiàn)不好，于是就采用異步，服務(wù)器壓力減少，客戶端滿意度提高。。
sQueryString是SQL（增刪查改）語(yǔ)句
public
Boolean
ExecSQL(string
sQueryString)
{
SqlConnection
con
=
new
SqlConnection(ConfigurationManager.AppSettings["conStr"]);
con.Open();
SqlCommand
dbCommand
=
new
SqlCommand(sQueryString,
con);
try
{
dbCommand.ExecuteNonQuery();
con.Close();
}
catch
{
con.Close();
return
false;
}
return
true;
}
}
建立一個(gè)類，明自己取，然后調(diào)用就是了
例如：
類
BC=NEW
類（）；
STRING
ist="INSERT
INTO
XX(1,2,3)VALUES(A,B,C)";
BC.ExecSQL（ist）;
就可以了
如果樓主熟悉VB6，可以直接在項(xiàng)目中添加ADODB的Com引用，這樣你就可以像VB6那樣操作數(shù)據(jù)庫(kù)了！
另外
.NET Framework中連接數(shù)據(jù)庫(kù)要用到ADO.NET。如果要操作Access數(shù)據(jù)庫(kù)，要用到System.Data.OleDb命名空間下的許多類。
比如按樓主所說(shuō)，“我想在textbox1中顯示表一中【一些數(shù)據(jù)】字段下的第一個(gè)內(nèi)容”：
'首先導(dǎo)入命名空間
Imports System.Data
Imports System.Data.OleDb
'然后在某一個(gè)事件處理程序中寫：
Dim conn As New OleDbConnection("Provider=Microsoft.ACE.OLEDB.12.0;Data Source=數(shù)據(jù)庫(kù).accdb;Jet OLEDB:Database Password=MyDbPassword")
Dim command As New OleDbCommand("Select * From 數(shù)據(jù)表", conn)
conn.Open() '打開(kāi)數(shù)據(jù)庫(kù)連接
Dim reader As OleDbDataReader = command.ExecuteReader() '執(zhí)行SQL語(yǔ)句，返回OleDbDataReader 對(duì)象
Do While reader.Read() '讀取一條數(shù)據(jù)
textbox1.Text += reader("一些數(shù)據(jù)") VbCrLf
Loop
reader.Close() '關(guān)閉OleDbDataReader
conn.Close() '關(guān)閉連接
1、 用The SQL Server .NET Data Provider連接數(shù)據(jù)庫(kù)
The SQL Server .NET Data Provider是利用SqlConnection類來(lái)連接SQL Server7.0或更高版本的數(shù)據(jù)庫(kù)，
SqlConnection類位于名稱空間System.Data.SqlClient下。
連接代碼：
Dim sqlConnection1 As SqlClient.SqlConnection
Dim strConnect As String=”data source=服務(wù)器名;initial catalog=數(shù)據(jù)庫(kù)名;user id=sa;password=;”
sqlConnection1=New System.Data.SqlClient.SqlConnection(strConnect)
sqlConnection1.open ‘打開(kāi)數(shù)據(jù)庫(kù)
sqlConnection1.close ‘關(guān)閉連接，釋放資源
2、 用The OLE DB .NET Data Provider連接數(shù)據(jù)庫(kù)
上面已經(jīng)說(shuō)過(guò)，利用The OLE DB .NET Data Provider可以訪問(wèn)Access、Oracle和SQL Server等種數(shù)據(jù)
庫(kù)，那么，它是怎樣訪問(wèn)這些數(shù)據(jù)庫(kù)的呢？The OLE DB .NET Data Provider是通過(guò)位于名稱空間Sy
stem.Data.OleDb類庫(kù)下的OleDbConnection類來(lái)連接這三種不同類型的數(shù)據(jù)庫(kù)的。下面舉例說(shuō)明:
1)連接SQL Server數(shù)據(jù)庫(kù)
Dim oleDbConnection1 As OleDb.OleDbConnection
Dim strConnect As Sting=”Provider=SQLOLEDB;Persist Security Info=False;Data Source=服務(wù)器名;Initial Catalog=數(shù)據(jù)庫(kù)名;User ID=sa;Password=;”
oleDbConnection1=New System.Data.OleDb.OleDbConnection(strConnect)
2)連接Access數(shù)據(jù)庫(kù)
假設(shè)要連接的Access數(shù)據(jù)庫(kù)名為“Example.mdb”，存放在d:\Data\目錄下。
Dim oleDbConnection1 As OleDb.OleDbConnection
Dim strConnect As Sting=”Provider=Microsoft.Jet.OLEDB.4.0;Data Source=d:\Data\ Example.mdb”
oleDbConnection1= New System.Data.OleDb.OleDbConnection(strConnect)
3)連接Oracle數(shù)據(jù)庫(kù)
Dim oleDbConnection1 As OleDb.OleDbConnection
Dim strConnect As Sting=”Provider=MSDAORA;Data Source=服務(wù)器名;User ID=用戶ID;Password=密碼;”
oleDbConnection1= New System.Data.OleDb.OleDbConnection(strConnect)
3、 用The ODBC .NET Data Provider連接數(shù)據(jù)庫(kù)
The ODBC .NET Data Provider連接數(shù)據(jù)庫(kù)是通過(guò)OdbcConnection類來(lái)實(shí)現(xiàn)的，這個(gè)類位于名稱空間
Microsoft.Data.Odbc下，而名稱空間Microsoft.Data.Odbc是封裝在Microsoft.Data.Odbc.dll文件下的。
由于篇幅有限，這里就只介紹連接Sql Server和Oracle數(shù)據(jù)庫(kù)的方法，其他數(shù)據(jù)庫(kù)的連接方法基本類
似，我就不再多講了。
1)連接Sql Server數(shù)據(jù)庫(kù)
Dim odbcDbConnetion1 As Microsoft.Data.OdbcConnection
Dim strConnect As Sting=”Driver={SQL Server};Server=服務(wù)器名;Uid=sa;pwd=;Database= 數(shù)據(jù)庫(kù)名;”
odbcDbConnetion1=New Microsoft.Data.OdbcConnection(strConnect)
2)連接Oracle數(shù)據(jù)庫(kù)
Dim odbcDbConnetion1 As Microsoft.Data.OdbcConnection
Dim strConnect As Sting=”Driver={Microsoft ODBC for Oracle};Server=服務(wù)器名;Uid=sa;pwd=;”
odbcDbConnetion1=New Microsoft.Data.OdbcConnection(strConnect)
四、總結(jié)
通過(guò)本文的介紹，讀者基本掌握了在Visual Basic.NET中用ADO.NET和ODBC.NET連接各種數(shù)據(jù)庫(kù)的方法
。以上三種驅(qū)動(dòng)針對(duì)不同的數(shù)據(jù)庫(kù)，它們的性能方面也有很大的不同：The SQL Server .NET Data Provider
的效率最高；The OLE DB .NET Data Provider的效率比較底；The ODBC .NET Data Provider的效率最慢。
具體連接哪一種數(shù)據(jù)庫(kù)選用哪一種數(shù)據(jù)驅(qū)動(dòng)要從工作效率方面來(lái)考慮。
以上回答你滿意么？
你說(shuō)這么一大篇全是業(yè)務(wù)邏輯，沒(méi)說(shuō)明你遇到的技術(shù)性問(wèn)題在哪
.net自帶的config文件來(lái)配置連接字符串，比ini好N倍，如果你非要用ini那么自己解決問(wèn)題
檢測(cè)是否能連接用Connection.Open加try catch就可以
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
請(qǐng)采納。
重慶分公司
重慶分公司
