在选择日期asp.net c#中添加BETWEEN语句后，字符串未被识别为有效日期时间

Question

我在添加语句 BETWEEN 以在两个日期之间进行选择并显示数据后出现此问题。在此之前，当我只选择一个日期时它会起作用。当我想选择日期以外的其他值时会出现此问题。似乎字符串未被识别为有效的日期时间。但如果我只选择日期或日期的值，它不会出现任何错误。为什么会这样？当我只有一个日期可供选择但当我在日期中的语句之间添加错误时，它可以完美运行。到目前为止，这是我的代码。

 if (!string.IsNullOrEmpty(DropDownListSearchJO.SelectedValue) || (!string.IsNullOrEmpty(DropDownListSearchLine.SelectedValue)) || (!string.IsNullOrEmpty(TextBoxSearchRec.Text)) || (!string.IsNullOrEmpty(TextBoxSearchRec2.Text)) || (!string.IsNullOrEmpty(DropDownListProcess.SelectedValue)))
       {

           try
           {
               con.Open();

               //select data from CutPanelCard
               query = "select a.req_id, a.prod_line, a.jo_no, a.buyer, a.request_date,CONVERT(VARCHAR(10),a.need_by_date ,101) as need_by_date, a.qty, a.username, b.process_id from CutPanelCard a LEFT JOIN CutPanelConfirmation b on b.req_id = a.req_id ";

               //check if dropdownJO not empty so query the data
               if (!string.IsNullOrEmpty(DropDownListSearchJO.SelectedValue))
               {
                   query += "where jo_no=@jo_no and status='F' ";
                   cmd = new SqlCommand(query, con);
                   cmd.Parameters.AddWithValue("@jo_no", DropDownListSearchJO.SelectedValue);
                   checking = true;

               }

               //check if dropdownLine not empty so query the data
               if (!string.IsNullOrEmpty(DropDownListSearchLine.SelectedValue))
               {
                   if (checking == true)
                   {
                       query += "and prod_line=@prod_line and status='F' ";
                       cmd = new SqlCommand(query, con);
                       cmd.Parameters.AddWithValue("@prod_line", DropDownListSearchLine.SelectedValue);
                       cmd.Parameters.AddWithValue("@jo_no", DropDownListSearchJO.SelectedValue);
                       cmd.Parameters.AddWithValue("@from", Convert.ToDateTime(TextBoxSearchRec.Text));
                       cmd.Parameters.AddWithValue("@to", Convert.ToDateTime(TextBoxSearchRec2.Text));
                   }
                   else
                   {
                       query += "where prod_line=@prod_line and status='F' ";
                       cmd = new SqlCommand(query, con);
                       cmd.Parameters.AddWithValue("@prod_line", DropDownListSearchLine.SelectedValue);
                       cmd.Parameters.AddWithValue("@jo_no", DropDownListSearchJO.SelectedValue);
                       checking = true;
                   }
               }

              //check if dropdownProcess not empty so query the data
               if (!string.IsNullOrEmpty(DropDownListProcess.SelectedValue))
               {
                       if (checking == true)
                       {
                           query += "and a.req_id not in (select req_id from cutpanelconfirmation where process_id = @process_id) and status='F' ";
                           cmd = new SqlCommand(query, con);
                           cmd.Parameters.AddWithValue("@processs_id", DropDownListProcess.SelectedValue);
                           cmd.Parameters.AddWithValue("@jo_no", DropDownListSearchJO.SelectedValue);
                           cmd.Parameters.AddWithValue("@prod_line", DropDownListSearchLine.SelectedValue);
                       }
                       else
                       {
                           query += "where a.req_id not in (select req_id from cutpanelconfirmation where process_id = @process_id) and status='F' ";
                           cmd = new SqlCommand(query, con);
                           cmd.Parameters.AddWithValue("@process_id", DropDownListProcess.SelectedValue);
                           cmd.Parameters.AddWithValue("@jo_no", DropDownListSearchJO.SelectedValue);
                           cmd.Parameters.AddWithValue("@prod_line", DropDownListSearchLine.SelectedValue);
                           checking = true;
                       }
               }

               //check if textboxRec not empty so query the data
               if ((!string.IsNullOrEmpty(TextBoxSearchRec.Text)) || (!string.IsNullOrEmpty(TextBoxSearchRec2.Text)))
               {
                   if (checking == true)
                   {
                       query += "and need_by_date BETWEEN @from and @to and status='F' ";
                       cmd = new SqlCommand(query, con);
                       cmd.Parameters.AddWithValue("@from", Convert.ToDateTime(TextBoxSearchRec.Text));
                       cmd.Parameters.AddWithValue("@to", Convert.ToDateTime(TextBoxSearchRec2.Text));
                       cmd.Parameters.AddWithValue("@jo_no", DropDownListSearchJO.SelectedValue);
                       cmd.Parameters.AddWithValue("@prod_line", DropDownListSearchLine.SelectedValue);
                       cmd.Parameters.AddWithValue("@process_id", DropDownListProcess.SelectedValue);
                   }
                   else
                   {
                       query += "where need_by_date BETWEEN @from and @to and status='F' ";
                       cmd = new SqlCommand(query, con);
                       cmd.Parameters.AddWithValue("@need_by_date", Convert.ToDateTime(TextBoxSearchRec.Text));
                       cmd.Parameters.AddWithValue("@to", Convert.ToDateTime(TextBoxSearchRec2.Text));
                       cmd.Parameters.AddWithValue("@jo_no", DropDownListSearchJO.SelectedValue);
                       cmd.Parameters.AddWithValue("@prod_line", DropDownListSearchLine.SelectedValue);
                       cmd.Parameters.AddWithValue("@process_id", DropDownListProcess.SelectedValue);
                       checking = true;
                   }
               }


               //show the query based on ascending req_id and last_update
               query += "order by a.req_id, b.last_update DESC ";
               cmd = new SqlCommand(query, con);
               cmd.Parameters.AddWithValue("@from", Convert.ToDateTime(TextBoxSearchRec.Text));
               cmd.Parameters.AddWithValue("@to", Convert.ToDateTime(TextBoxSearchRec2.Text));
               cmd.Parameters.AddWithValue("@jo_no", DropDownListSearchJO.SelectedValue);
               cmd.Parameters.AddWithValue("@prod_line", DropDownListSearchLine.SelectedValue);
               cmd.Parameters.AddWithValue("@process_id", DropDownListProcess.SelectedValue);

               SqlDataAdapter da = new SqlDataAdapter(cmd);

               //remove duplicated req_id before bind into gridview
               DataTable dtRemoveDuplicate = new DataTable();
               da.Fill(dtRemoveDuplicate);
               dtRemoveDuplicate = DeleteDuplicateFromDataTable(dtRemoveDuplicate, "req_id");
               GridView1.DataSource = dtRemoveDuplicate;
               GridView1.DataBind();

               con.Close();
           }

Answer 1

试试这个。

query += "and a.need_by_date BETWEEN @from and @to and status='F' ";
query += "where a.need_by_date BETWEEN @from and @to and status='F' ";