问 SQL过程失败，原因是Varchar转换为DateTime错误

EN

我有一个我写的存储过程的问题，我可以在management studio中调用它，它工作得很好，但是当我调用da.Fill(dt)时，从我的代码后台调用它时会出现这个错误 The conversion of a varchar data type to a datetime data type resulted in an out-of-range value. 。

这里真正让我困惑的是，我实际上并没有将任何东西从varchar转换成日期时间，我对日期变量所做的最多的事情就是将它们格式化为不同的日期时间格式。

我的VB.Net代码

  Private Function dbGetEvents(ByVal start As DateTime, ByVal days As Integer) As DataTable
      Dim dt As New DataTable()
      Dim conn As New SqlConnection(ConfigurationManager.ConnectionStrings("Blueprint").ToString())
      Dim cmd As New SqlCommand
      cmd.CommandType = CommandType.StoredProcedure
      cmd.CommandText = "spGetEventDetails"
      cmd.Parameters.AddWithValue("@start", start)
      cmd.Parameters.AddWithValue("@end", start.AddDays(days))
      cmd.Parameters.AddWithValue("@userid", ddlUser.SelectedValue)
      cmd.Connection = conn
      Using da As New SqlDataAdapter(cmd)
         conn.Open()
         da.Fill(dt)
         conn.Close()
      End Using
      Return dt
   End Function

我的SQL过程：

CREATE PROCEDURE spGetEventDetails
    @start AS DATETIME,
    @end AS DATETIME,
    @userid AS INT
BEGIN
SET @start = CONVERT(CHAR(10), CAST(@start AS DATETIME), 23)
SET @end = CONVERT(CHAR(10), CAST(@end AS DATETIME), 23)
    -- GET DETAILS FOR TICKETS
    SELECT
        [ev].[id]                           AS [EventID],
        CAST([tck].[TicketID] AS NVARCHAR)  AS [TicketID],
        [tck].[Description]                 AS [Description],
        [ev].[eventstart]                   AS [Start],
        [ev].[eventend]                     AS [End],
        [ev].[status]                       AS [Status],
        [ev].[type]                         AS [EventType],
        CAST([tck].[Type] AS NVARCHAR)      AS [Type],
        CAST([tck].[Product] AS NVARCHAR)   AS [Product],
        CAST([tck].[Severity] AS NVARCHAR)  AS [Severity],
        [ev].[resource_id]                  AS [resource_id],
        CAST(pers.FirstName AS NVARCHAR)    AS [FirstName],
        CAST(pers.Surname AS NVARCHAR)      AS [Surname],
        CAST(tck.LogDate AS NVARCHAR)       AS [LogDate]
        tblSupportEvent ev
        tblTicketsInEvents tie
        ev.id =tie.eventID
        SupportTicketsTbl tck
        tie.ticketID = tck.TicketID 
        PersonnelTbl pers
        pers.ID = tck.LoggedBy 
    WHERE
        ev.type = 1
        NOT (([eventend] <= @start) OR ([eventstart] >= @end))  
        resource_id <> 0  
        ev.resource_id = @userid  
UNION 
    -- GET THE DETAILS FOR NON TICKET ITEMS
    SELECT
        [ev].[id]           AS [EventID],
        ''                  AS [TicketID],
        [nti].[Description] AS [Description],
        [ev].[eventstart]   AS [Start],
        [ev].[eventend]     AS [End],
        [ev].[status]       AS [Status],
        [ev].[type]         AS [EventType],
        ''                  AS [Type],
        ''                  AS [Product],
        ''                  AS [Severity],
        [ev].[resource_id]  AS [resource_id],
        ''                  AS [FirstName],
        ''                  AS [Surname],
        ''                  AS [LogDate]
        tblSupportEvent ev
        tblNonTicketsInEvents nte
        ev.id = nte.eventID 
        tblNonTicketItems nti
        nte.nonTicketID = nti.id    
    WHERE
        ev.type = 2
        NOT (([eventend] <= @start) OR ([eventstart] >= @end))  
        resource_id <> 0  
        ev.resource_id = @userid  
END

我看不出这个错误可能来自哪里，在SQL management studio中测试运行它没有错误，我非常确定错误是在VB中。

我的第一个想法是，也许我在@start / @end值中传递的参数没有被识别为DateTime，所以我尝试添加如下参数：

 Dim p As New SqlParameter
  p.SqlDbType = SqlDbType.DateTime
  p.ParameterName = "@start"