使用組合框查詢數據庫

Question

我有一整天的組合框，但是當選擇一天時，所有的日子都顯示在我的數據網格中......我如何使用組合框中的一個選定值只搜索該值。

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" 
     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

你逝去的cbDay爲一個字符串，嘗試改變這一行

Dim SqlQuery As String = "SELECT Time, Activity, Equipment FROM TimeTable WHERE Day = cbDay" 

到這樣的事情

Dim SqlQuery As String = String.Format("SELECT Time, Activity, Equipment FROM TimeTable WHERE Day = {0}", cbDay.Text) 

Answer 2

您可以使用下面的代碼

簡單地做一個過濾器在你的datagridview

Dim column As String = 'Your weekday column Name in Datagridview 
Private Sub ComboBox1_SelectedIndexChanged(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles ComboBox1.SelectedIndexChanged 

    Dim rows = ds.Tables(0).Select("Convert(" & column & ", 'System.String') LIKE '*" + ComboBox1.SelectedItem + "*'") 

    Try 
     DGTimeTable.DataSource = rows.CopyToDataTable 
    Catch ex As Exception 
    End Try 
End Sub