vb点虐 与数据库交换 vbnet连接数据库

vb点虐 怎么操作数据库

如果楼主熟悉VB6，可以直接在项目中添加ADODB的Com引用，这样你就可以像VB6那样操作数据库了！

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另外

.NET

Framework中连接数据库要用到ADO.NET。如果培嫌要操作Access数据库，要用到System.Data.OleDb命名空间下的许多类。

比如按楼主所说，“配举手我想在textbox1中显示表一中【一些数据】字段下的第一个内容”：

'首先导入命名空间

Imports

System.Data

Imports

System.Data.OleDb

'然后在某一个事件处理程序中写：

Dim

conn

As

New

OleDbConnection("Provider=Microsoft.ACE.OLEDB.12.0;Data

Source=数据库.accdb;Jet

OLEDB:Database

Password=MyDbPassword")

Dim

command

As

New

OleDbCommand("Select

*

From

数据表",

conn)

conn.Open()

'打开数据库连接

Dim

reader

As

OleDbDataReader

=

command.ExecuteReader()

'执行SQL语句，返回OleDbDataReader

对象

Do

While

reader.Read()

'读取答前一条数据

textbox1.Text

+=

reader("一些数据")

VbCrLf

Loop

reader.Close()

'关闭OleDbDataReader

conn.Close()

'关闭连接

vb点虐 中如何把DataGridView当前行的值跟新到ACCESS数据库

参考一下下耐桐面这段代码：

Imports System.Data.OleDb

Public Class Form1

Dim SqlCOM As OleDbConnection

Dim SqlUse As OleDbDataAdapter

Dim Dt As DataSet

Private Sub Form1_Load(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles MyBase.Load

Try

'连接数据库

SqlCOM = New OleDbConnection("Provider=Microsoft.ACE.OLEDB.12.0;Data Source=C:\Users\LP\Documents\Database1.accdb")

'执行数据命令获取表

SqlUse = New OleDbDataAdapter("SELECT * FROM 表1", SqlCOM)

Dt = New DataSet

SqlUse.Fill(Dt) '放入dataset中

Catch

MsgBox(Err.Description, 48)

End Try

End Sub

Private Sub Button1_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button1.Click

Try

DataGridView1.DataSource = Dt.Tables(0).DefaultView 'DVG与猛厅DADASET同步数据显示

Catch

MsgBox(Err.Description, 32)

End Try

End Sub

Private Sub Button2_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button2.Click

Try

Dim ass As New OleDbCommandBuilder(SqlUse) '关联DataSet和数据库的操作(更新)

SqlUse.UpdateCommand = ass.GetUpdateCommand() '执行更新所需的 OleDbCommand 对象

SqlUse.Update(Dt.Tables(0)) '昌知坦执行OleDbDataAdapter的Update更新数据库

Catch

MsgBox(Err.Description, 32)

Finally

MsgBox("更新成功", 64)

End Try

End Sub

End Class

VB点虐 如何调用ACCESS数据库中的数据

使用向导设置数据库连接的好处是省去写代码的过程，弊端是不易更改连接

使用代码连接的好处是需要编写代码，但容易更改和维护

如：数据库的位置变化，直接更改代码显然容易一些

代码：

imports System.data.oledb /*引用命名空间*/

dim cnstr = "provider=microsoft.jet.oledb.4.0,data source=Access数据库文件位置" /*定义连接字符串枯老*/

dim cn as oledbconnection = new oledbconnection(cnstr) /*定义连接*/

cn.open() /*打开连接*/

sqlstr="御败备select... from... 或其他sql"

dim cmd as sqlcommand=new sqlcommand()

cmd点抗 mandtext=sqlstr

cmd.connection=cn

/*以上是建立执行语句*/

cmd.executenonquery() 不返回结果

cmd.executescalar() 返回单个结果

cmd.executereader() 返回结果集

/*以上是执行sql语句的方法*/

cn.close() /*关闭连接*/

你要做用户验证的话，先根据用户名查询对应的密码，再判断用户输入镇毁的密码和查询结果是不是相同就可以了

用cmd.executescalar() 这个方法

VB.NET 服务器与客户端数据交互问题？

客户端简单代码：

Imports System.Net.Sockets

Imports System.IO

Private Output As NetworkStream

Private Writer As BinaryWriter

Private Reader As BinaryReader

Dim StrSend As String

Dim client As New TcpClient '

client.Connect(servIP, 2006)

Output = client.GetStream

Writer = New BinaryWriter(Output)

Reader = New BinaryReader(Output)

StrSend = "字符串"

System.Threading.Thread.Sleep(100)

Writer.Write(StrSend)

Try

Message = Reader.ReadString

If Message = "OK" Then

LBinfo.Text = "成功！" '测试

Else

LBinfo.Text = "失败！"

End If

System.Threading.Thread.Sleep(100)

Catch ex As Exception

MessageBox.Show("Client Application Closing!")

Finally

Writer.Close()

Reader.Close()

Output.Close()

client.Close()

End Try

服务器端

用线程

Imports System.Net.Sockets

Imports System.IO

Imports System.Threading

Imports System.Windows.Forms

Private Connection As Socket

Private readThread As Thread

Private SocketStream As NetworkStream

Private Writer As BinaryWriter

Private Reader As BinaryReader

Public Sub New()

MyBase.New()

'该调用是 Windows 窗体设计器所必需的。

InitializeComponent()

'者裂在 InitializeComponent() 调用之后首梁闭添加任渣雀何初始化

readThread = New Thread(AddressOf RunServer)

readThread.Start()

End Sub

Public Sub RunServer()

Dim Listener As TcpListener

Try

Listener = New TcpListener(Net.IPAddress.Parse("192.168.1.16"), 2006)

Listener.Start()

While True

Connection = Listener.AcceptSocket 'accept an incoming connection

SocketStream = New NetworkStream(Connection) 'create networkstream object associated with socket

Writer = New BinaryWriter(SocketStream) 'create object for transferring data across stream

Reader = New BinaryReader(SocketStream) 'read string data sent from client

Try

Do

strIncept = Reader.ReadString

strIncept = DataDisp(strIncept) '此处插入数据处理程序()

SendInfoToClient(strIncept) 'send to client

Loop While Connection.Connected

Catch ex As Exception

MsgBox(ex.ToString)

Finally

Writer.Close()

Reader.Close()

SocketStream.Close()

End Try

End While

Catch ex As Exception

MsgBox(ex.ToString)

End Try

End Sub

Public Sub SendInfoToClient(ByVal Info As String)

'Send to client

Try

If Connection.Connected Then

Writer.Write(Info)

Connection.Close()

End If

Catch ex As SocketException

MessageBox.Show(ex.ToString)

End Try

End Sub

整个过程都有了