Question

我的组合框在选择语句中没有工作，如果我输入我之后的值，语句本身就可以工作。我认为组合框本身可能有问题，或者有人看到我的代码有问题吗？

Private Sub btnViewTimeTable_Click(sender As Object, e As EventArgs) Handles btnViewTimeTable.Click

    If (cbDay.Text = "Monday" Or cbDay.Text = "Tuesday" Or cbDay.Text = "Wednesday" Or cbDay.Text = "Thursday" Or cbDay.Text = "Friday" Or cbDay.Text = "Saturday" Or cbDay.Text = "Sunday") Then
        Dim SqlQuery As String = "SELECT Time, Activity, Equipment FROM TimeTable WHERE Day = 'cbDay.text'"
        Dim da As OleDbDataAdapter = New OleDbDataAdapter(SqlQuery, conn)
        Dim ds As DataSet = New DataSet
        da.Fill(ds, "Table")
        Dim dt As DataTable = ds.Tables("Table")

        With DGTimeTable
            .AutoGenerateColumns = True
            .DataSource = ds
            .DataMember = "Table"
        End With

        With DGTimeTable
            .Columns(0).Width = 108
            .Columns(1).Width = 154
            .Columns(2).Width = 278
            Me.DGTimeTable.DefaultCellStyle.WrapMode = DataGridViewTriState.True
            Me.DGTimeTable.AutoSizeRowsMode = DataGridViewAutoSizeRowsMode.AllCells
        End With

    Else
        MsgBox("Please Select a Day!")

    End If

End Sub

Answer 1

更改这些初始行

Dim SqlQuery As String = "SELECT Time, Activity, Equipment " & _ 
                         "FROM TimeTable WHERE Day = ?"
Dim da As OleDbDataAdapter = New OleDbDataAdapter(SqlQuery, conn)
da.SelectCommand.Parameters.AddWithValue("@p1", cbDay.text)
Dim ds As DataSet = New DataSet
da.Fill(ds, "Table")
....

在原始代码中，您尝试在单引号之间传递组合的名称及其属性文本，但是这样文本被解释为升级，这意味着数据库引擎搜索列{{1}的记录包含字符串值Day而不是组合框文本的实际值

还有另一个问题。您使用cboDay.text作为数据库，因此单词TIME和DAY是MS-Access中的保留关键字，除非将它们括在方括号中，否则无法将它们用作列名。如果仍有可能，我建议更改这些列的名称，因为每次使用此表时都会遇到这个烦人的问题。

Jet-Sql

Combobox不使用选择语句

1 个答案: