如何从访问数据中获取数据到组合框

Question

Public Class AdminP_Time2

    Dim conn As OleDbConnection
    Dim cmd As OleDbCommand
    Dim sql As String
    Dim dr As OleDbDataReader

    Private Sub AdminP_Time2_Load(sender As Object, e As EventArgs) Handles MyBase.Load    
        conn = New OleDbConnection("Provider=Microsoft.ACE.OLEDB.12.0;Data Source=Database.accdb;Persist Security Info=False;")
        conn.Open() 'opens the connection
        sql = "SELECT * FROM LecturerName"
        cmd = New OleDbCommand(sql, conn)

        dr = cmd.ExecuteReader

        If dr.Read = True Then
            ComboBox1.Text = dr("LecturerName")
        End If

为什么我的组合框只显示 1 个项目？谁能帮我？我想把我的访问数据带到 Combobox。

Answer 1

您自己的代码不起作用的原因是您只读取了一条记录。你需要一个循环，例如

While dr.Read()
    ComboBox1.Items.Add(dr("LecturerName"))
End While

也就是说，您的代码应该更像这样：

Using conn As New OleDbConnection("Provider=Microsoft.ACE.OLEDB.12.0;Data Source=Database.accdb;Persist Security Info=False;"),
      cmd As New OleDbCommand("SELECT * FROM LecturerName", conn)
    conn.Open()

    Using dr As OleDbDataReader = cmd.ExecuteReader()
        Dim tbl As New DataTable

        tbl.Load(dr)

        With ComboBox1
            .DisplayMember = "LecturerName"
            .DataSource = tbl
        End With
    End Using
End Using

这会将数据加载到 DataTable 并将其绑定到 ComboBox。如果您希望能够通过 ComboBox 的 SelectedValue 访问所选记录的 PK 值，您还应该设置 ComboBox 的 ValueMember。您还应该指定要从中检索数据的列而不是使用通配符，除非您真的想要每一列。

Answer 2

这是一个很好的例子。

Sub TryThis()

Dim db As DAO.Database
   Dim qdf As DAO.QueryDef
   Dim strSQL As String
   Set db = CurrentDb
   Set qdf = db.QueryDefs("qryStaffListQuery”)

   strSQL = "SELECT tblStaff.* ” & _
                 "FROM tblStaff ” & _
                 "WHERE tblStaff.Office='" & Me.cboOffice.Value & "’ ” & _
                 "AND tblStaff.Department='" & Me.cboDepartment.Value & "’ ” & _
                 "AND tblStaff.Gender='" & Me.cboGender.Value & "’ ” & _
                 "ORDER BY tblStaff.LastName,tblStaff.FirstName;”
End Sub

您可以在下面的 link 中找到所有详细信息。

http://www.fontstuff.com/access/acctut17.htm

如何从访问数据中获取数据到组合框

How to take data from access data to Combobox

vb.net

ms-access

vb.net-2010