Vb.net 我想在sqlite中使用两个文本框（textbox4.text和textbox5.text=variable）在两个日期之间进行查询

Dim query As String=从mytable中选择*，其中strftime“%Y-%m-%d”介于“TextBox4.text”和“TextBox5.text”之间

无法分配查询变量？ Datagridview结果=空

信息：Datagridview日期格式=2018-01-01 17:42:24

    Dim btarihyil As String
    btarihyil = DateTimePicker2.Value.ToString.Substring(6, 4)
    Dim btarihay As String
    btarihay = DateTimePicker2.Value.ToString.Substring(3, 2)
    Dim btarihgun As String
    btarihgun = DateTimePicker2.Value.ToString.Substring(0, 2)
    TextBox4.Text = btarihyil & "-" & btarihay & "-" & btarihgun

    Dim bttarihyil As String
    bttarihyil = DateTimePicker3.Value.ToString.Substring(6, 4)
    Dim bttarihay As String
    bttarihay = DateTimePicker3.Value.ToString.Substring(3, 2)
    Dim bttarihgun As String
    bttarihgun = DateTimePicker3.Value.ToString.Substring(0, 2)

    TextBox4.Text = btarihyil & "-" & btarihay & "-" & btarihgun
    TextBox5.Text = bttarihyil & "-" & bttarihay & "-" & bttarihgun

    Dim Yol As String = "Data Source=database1.s3db;version=3;new=False"
    Using MyConn As New SQLiteConnection(Yol)
        If (MyConn.State = ConnectionState.Closed) Then
            MyConn.Open()
        End If
        Dim Sorgu As String = "select * from mytable where strftime('%Y-%m-%d',tarih) between 'TextBox4.text' and 'TextBox5.text' "
        Using MyCmd As New SQLiteCommand(Sorgu, MyConn)
            Dim Da As New SQLiteDataAdapter(MyCmd)
            Dim Ds As New DataSet
            Dim Dt As New DataTable
            Ds.Reset()
            Da.Fill(Ds)
            Dt = Ds.Tables(0)

            Dim Bs As New BindingSource With {.DataSource = Dt}
            DataGridView1.DataSource = Bs
            Bs.MoveLast()

            MyConn.Close()
            MyCmd.Dispose()
            MyConn.Dispose()
        End Using
    End Using


End Sub

您正在查询中使用TextBox4.Text和TextBox5.Text。这不会将文本框的值传递给查询。因此，它将导致错误

您还需要使用参数化查询来避免语法错误。 另外，我不知道为什么要使用strftime函数。该函数仅用于格式化

遵循我使用参数化查询方法重新编写的代码

Dim Yol As String = "Data Source=database1.s3db;version=3;new=False"
Using MyConn As New SQLiteConnection(Yol)
    If (MyConn.State = ConnectionState.Closed) Then
        MyConn.Open()
    End If
    Dim Sorgu As String = "select * from mytable where tarih between @startDate and @endDate "
    Using MyCmd As New SQLiteCommand(Sorgu, MyConn)
        Dim startDate as new SQLiteParameter("@startDate")
        startDate.Value = DateTimePicker2.Value
        Dim endDate as new SQLiteParameter("@endDate")
        endDate.Value = DateTimePicker3.Value
        MyCmd.Parameters.Add(startDate)
        MyCmd.Parameters.Add(endDate)

        Dim Da As New SQLiteDataAdapter(MyCmd)
        Dim Ds As New DataSet
        Dim Dt As New DataTable
        Ds.Reset()
        Da.Fill(Ds)
        Dt = Ds.Tables(0)

        Dim Bs As New BindingSource With {.DataSource = Dt}
        DataGridView1.DataSource = Bs
        Bs.MoveLast()

        MyConn.Close()
        MyCmd.Dispose()
        MyConn.Dispose()
    End Using
End Using

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这将帮助您解决问题。

C代码在哪里？很抱歉我重新编辑了一个很长的错误。您在查询中使用的是文本字符串“TextBox4.text”，而不是文本框的值。使用SqliteParameters添加值。例如：Dim Sorgu As String=select*from mytable，其中strftime“%Y-%m-%d”，tarih介于values@firstdate和values@lastdateMyCmd.Parameters.AddWithValue@firstdate，TextBox4.Text MyCmd.Parameters。AddWithValue@lastdate,TextBox5.TextThank you Dim Sorgu As String=select*from Hareketler，其中strftime“%Y-%m-%d”，介于@firstdate和@lastdate worke之间。我使用strftime函数，因为datagridview data=2018-01-01 17:42:24。。。很乐意帮忙