错误 "Conversion failed when converting date and/or time from character string"

Question

我有休假的 SQL 查询，在获取日期值时失败：

 String strQuery = @"SELECT TOP 100000" +
    "[dbo].[Service].[company_name] AS 'Company Name', [dbo].[Service].[status_description] AS 'Status Description'," +
    "DATEPART(month, [dbo].[Service].[date_entered]) AS 'Month', COUNT([dbo].[Service].[status_description]) AS 'Count'" +
    "FROM [dbo].[Service] WITH(NOLOCK)" +
    "WHERE  ([dbo].[Service].[status_description] = @Status)" +

    // ****  I used the following to get values from Ajax CalendarExtender 
    // **** (Ajax Format from: yyyy-MM-ddTHH:mm:ss.mmm to: yyyy-MM-ddT23:59:59.000) *******
    "AND ([dbo].[Service].[date_entered] BETWEEN '@DateFrom' AND '@DateTo')" +

    "GROUP BY [dbo].[Service].[company_name], [dbo].[Service].[status_description]," +
    "DATEPART(month, [dbo].[Service].[date_entered])" +
    "ORDER BY [dbo].[Service].[status_description] ASC;";

    System.Globalization.CultureInfo en = new System.Globalization.CultureInfo("en-US");
    SqlConnection con = new SqlConnection(strConnString);
    SqlCommand cmd = new SqlCommand(strQuery + "", con);
    cmd.Parameters.AddWithValue("@Status", DdlTickets.SelectedItem.Value);
    cmd.Parameters.AddWithValue("@DateFrom", TxtDateFrom.Text);
    cmd.Parameters.AddWithValue("@DateTo", TxtDateTo.Text);        

    SqlDataAdapter da = new SqlDataAdapter(cmd);
    DataSet ds = new DataSet();
    cmd.Connection = con;
    try
    {
        con.Open();
        if (DdlTickets.Items.Count > 1)
        {
            da.Fill(ds, strQuery);

            // *** the values come from Ajax, but when It gets to fill the Gridview, it fails with error ****

            GridView1.DataSource = ds.Tables[strQuery];
            GridView1.DataBind();
            BtnCSV.Visible = true;
        }
        if (GridView1.Rows.Count <= 0)
        {
            BtnCSV.Visible = false;
        }
        else
        {
            //Set Later
        }
    }
    catch (Exception ex)
    {
        throw ex;
    }
    finally
    {
        con.Close();
        con.Dispose();
    }

我尝试使用以下代码从 CalendarExtender 转换默认值，但它不起作用：

cmd.Parameters.AddWithValue("@DateFrom", DateTime.ParseExact(TxtDateFrom.Text, "yyyy-MM-ddTHH:mm:ss.mmm", CultureInfo.InvariantCulture));
cmd.Parameters.AddWithValue("@DateTo", DateTime.ParseExact(TxtDateTo.Text, "yyyy-MM-ddTHH:mm:ss.mmm", CultureInfo.InvariantCulture));

如果我执行以下查询而不是上面的查询，并直接获取值，它就可以工作：

"AND ([dbo].[Service].[date_entered] BETWEEN '2015-04-02T00:00:00.000' AND '2015-09-02T23:59:59.000')" +

有什么可能导致错误的想法吗？非常感谢您的帮助！

Answer 1

您的参数不需要使用单引号。使用单引号，您的数据库管理器会将它们视为 string literal 而不是参数。

只需删除它们。如果除此之外一切正常，它将起作用。

AND ([dbo].[Service].[date_entered] BETWEEN @DateFrom AND @DateTo)

还有一些事情；

使用 using statement 自动处理您的 SqlConnection、SqlCommand 和 SqlDataAdapter 对象，而不是手动调用 Close 或 Dispose 方法。
不要使用AddWithValue方法。 It may generate unexpected and surprising results sometimes。使用 Add 方法重载来指定参数类型及其大小。

错误 "Conversion failed when converting date and/or time from character string"

Error "Conversion failed when converting date and/or time from character string"

c#

sql

asp.net

ajaxcontroltoolkit