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vb.net取数据库数据 vbnet操作数据库

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vb.net 如何操作数据库提取一段时间内的数据VB的数据库操作，我们都知道在Where子句中对于字符串类型 ， 用单引号
注意：凡是日期、时间类型，用井号，也就是#
所以，你的这个用
select * from 表名 where cdate(起始时间) between #" + CDate(txtStart.Text) + "# and #" + CDate(txtOver.Text) + “#“
vb如何读取数据库一行数据？'读取方法：
Imports System.IO
Public Class Form1
Private Sub Button1_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button1.Click
Me.ListBox1.Items.Clear()
Dim StrRed As StreamReader = New StreamReader("D:\111.txt", System.Text.Encoding.Default)
While Not StrRed.EndOfStream
Me.ListBox1.Items.Add(StrRed.ReadLine())
End While
StrRed.Dispose()
End Sub
End Class
'其它读写方法：
写入：
Private Sub Button2_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button2.Click
Dim strR As New StreamWriter("D:\111.txt", True)'参数True表示 在原来的数据上面添加，如果为False这删除原来的数据 重新写入数据
strR.WriteLine(Me.TextBox2.Text)
strR.Dispose()
End Sub
读?。?
Private Sub Button3_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button3.Click
Dim strR As New StreamReader("D:\111.txt")
While Not strR.EndOfStream
Me.TextBox1.Text += strR.ReadLine()vbCrLf
End While
strR.Dispose()
End Sub
用VB.net连接数据库怎么获取其数据如果您要连接SQL Server 您可以参考以下代码 。
您需要提供您的连接字符串“connectionString”
Public Shared Function Query(ByVal SQLString As String) As DataSet
Using connection As New SqlConnection(connectionString)
Dim ds As New DataSet()
Try
connection.Open()
Dim command As New SqlDataAdapter(SQLString, connection)
command.Fill(ds, "ds")
Catch ex As System.Data.SqlClient.SqlException
Throw New Exception(ex.Message)
End Try
Return ds
End Using
End Function
这是一个返回DataSet的函数 。
调用非常简单 。
如果您有什么不清楚的可以继续追问！希望能帮到您！
VB.NET怎么获取本机的数据库这里以OERACLE数据库为例 vb.net取数据库数据：
Provider=MSDAORA;data source =主机名:1521/ORCL;User ID=system;Password=ORACLE;Unicode=True
Dim myConn As Data.OleDb.OleDbConnection
myConn = New System.Data.OleDb.OleDbConnection()
myConn.ConnectionString = strCon
myConn.Open()
求用vb.net写一个读取数据库数据的简单操作 。Option Explicit On
Option Strict On
Imports System
Imports System.Data
Imports System.Data.SqlClient
Public Class Program
Public Shared Sub Main()
Dim connectionString As String = _
"Data Source=(local);Initial Catalog=Northwind;" _
"Integrated Security=true"
' Provide the query string with a parameter placeholder.
Dim queryString As String = _
"SELECT ProductID, UnitPrice, ProductName from dbo.Products " _
"WHERE UnitPrice@pricePoint " _
"ORDER BY UnitPrice DESC;"
' Specify the parameter value.
Dim paramValue As Integer = 5
' Create and open the connection in a using block. This
' ensures that all resources will be closed and disposed
' when the code exits.
Using connection As New SqlConnection(connectionString)
' Create the Command and Parameter objects.
Dim command As New SqlCommand(queryString, connection)
command.Parameters.AddWithValue("@pricePoint", paramValue)
' Open the connection in a try/catch block.
' Create and execute the DataReader, writing the result
' set to the console window.
Try
connection.Open()
Dim dataReader As SqlDataReader = _

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