System.Data.SqlClient.SqlException：無效的列名'conferID'

Question

我試圖從數據庫中檢索會議的特定日期以顯示在網頁上。閱讀ConferenceID如下所示：

conferID = reader["ConferenceID"].ToString(); 

我想的頁面從ConferenceID =僅顯示日期「3」，但我也從ConferenceID =獲得日期「1」和ConferenceID =「2」時，我從下面的代碼中刪除（ConferenceID = conferID）。但是，如果我將（ConferenceID = conferID）添加回代碼，則頁面打破了。如果我將這些代碼放在SQL中進行測試並更改（ConferenceID = conferID）爲（ConferenceID ='3'），它就會起作用。我現在失去了。任何幫助表示讚賞。

SqlCommand GetDates = new SqlCommand(@" 
WITH x AS (
      select MAX(ConferenceID) as ConferenceID, row_number() over(order by D.Dates) as SN, D.Dates 
      from Conference as T 
        inner join master..spt_values as N 
        on N.number between 0 and datediff(day, T.ConferenceBeginDate, T.ConferenceEndDate) 
        cross apply (select dateadd(day, N.number, T.ConferenceBeginDate)) as D(Dates) 
        where N.type ='P' AND (ConferenceID = conferID) group by ConferenceID, D.Dates 
       ) 
SELECT ConferenceID, SN, Dates 
FROM x 
WHERE SN <> (Select MAX(SN) from x) AND (ConferenceID = conferID) 
GROUP BY ConferenceID, SN, Dates", conn); 

Answer 1

請使用sql參數。

SqlCommand GetDates = new SqlCommand(@" 
WITH x AS (
      select MAX(ConferenceID) as ConferenceID, row_number() over(order by D.Dates) as SN, D.Dates 
      from Conference as T 
        inner join master..spt_values as N 
        on N.number between 0 and datediff(day, T.ConferenceBeginDate, T.ConferenceEndDate) 
        cross apply (select dateadd(day, N.number, T.ConferenceBeginDate)) as D(Dates) 
        where N.type ='P' AND (ConferenceID = @conferId) group by ConferenceID, D.Dates 
       ) 
SELECT ConferenceID, SN, Dates 
FROM x 
WHERE SN <> (Select MAX(SN) from x) AND (ConferenceID = @conferId) 
GROUP BY ConferenceID, SN, Dates", conn); 

GetDates.Parameters.AddWithValue("@conferId", conferId); 

這裏的問題是您試圖引用一個不存在的字段。我假設你試圖引用一個可用的字符串，因此你必須將它添加爲一個命名參數，然後通過它來分配它。

Answer 2

您需要添加conferID作爲Parameter。試試這個

SqlCommand GetDates = new SqlCommand(@" 
WITH x AS (
      select MAX(ConferenceID) as ConferenceID, row_number() over(order by D.Dates) as SN, D.Dates 
      from Conference as T 
        inner join master..spt_values as N 
        on N.number between 0 and datediff(day, T.ConferenceBeginDate, T.ConferenceEndDate) 
        cross apply (select dateadd(day, N.number, T.ConferenceBeginDate)) as D(Dates) 
        where N.type ='P' AND (ConferenceID = @ConferenceID) group by ConferenceID, D.Dates 
       ) 
SELECT ConferenceID, SN, Dates 
FROM x 
WHERE SN <> (Select MAX(SN) from x) AND (ConferenceID = @ConferenceID) 
GROUP BY ConferenceID, SN, Dates", conn); 

GetDates.Parameters.Add(new SqlParameter("@ConferenceID", conferID));