Question

是否可以将多个数据库连接到程序？

我添加了一个数据库，但它始终通过＆＃34;数据源配置向导＆＃34;。我的应用程序处理一个主数据库，但我需要从其他数据库加载信息并将其添加到主数据库（用户将通过OpenFileDialog选择哪个数据库）。

Public Class Form1
    Private Sub TblTestBindingNavigatorSaveItem_Click(sender As Object, e As EventArgs) Handles TblTestBindingNavigatorSaveItem.Click
        Me.Validate()
        Me.TblTestBindingSource.EndEdit()
        Me.TableAdapterManager.UpdateAll(Me.TestdbDataSet)
    End Sub
    Private Sub Form1_Load(sender As Object, e As EventArgs) Handles MyBase.Load
        'TODO: This line of code loads data into the 'TestdbDataSet.tblTest' table. You can move, or remove it, as needed.
        Me.TblTestTableAdapter.Fill(Me.TestdbDataSet.tblTest)

    End Sub
    Private Sub btnLoad_Click(sender As Object, e As EventArgs) Handles btnLoad.Click
        Dim DBConnection As New OleDb.OleDbConnection
        '''' Dim con As New OleDb.OleDbConnection

        Dim dbProvider As String = "Provider=Microsoft.ACE.OLEDB.12.0;"
        'Dim dbSource As String = opnFile.ShowDialog()
        opnFile.ShowDialog()
        Dim ex As String = opnFile.FileName
        MessageBox.Show(ex)

        Dim dbSource As String = "DataSource=" & ex
        MessageBox.Show(dbSource, "Data Source String", MessageBoxButtons.OK, MessageBoxIcon.Information, MessageBoxDefaultButton.Button1)


        Dim DBDataSet As New DataSet
        '''' Dim ds As New DataSet
        Dim DBDataAdapter As OleDb.OleDbDataAdapter
        '''' Dim da As OleDb.OleDbDataAdapter
        DBConnection.ConnectionString = dbProvider & dbSource
        'DBDataAdapter = (sql, DBConnection)
    End Sub
End Class

另外，有人可以向我解释DataAdapter，DataConnection和DataSet中的链接吗？从我看来，DataConnection只是将应用程序连接到数据库的链接。 DataSet是数据库中的实际数据。那么DataAdapter是什么？

感谢您的帮助！

Answer 1

您可以使用数据库向导添加多个数据库。您将缺少绑定导航器，但您可以通过在项目中创建临时表单来轻松地将数据库添加到此，然后在删除临时表单之前复制绑定导航器。

Answer 2

请参阅此主题Display data from access using dataset使用以下内容。

将表格加载到数据集

后尝试这样的操作

For Each row1 In (From dr As DataRow In yourDataSet.Tables(0).Rows Select dr Where dr("Column_Name").ToString.StartsWith(yourstring)

somestring = row1("Column_Name").ToString

在VB.NET中添加多个数据库

2 个答案: