SqlCommand.ExecuteNonQuery（）總是返回0

Question

我想通過我的C＃代碼來處理UPDATE語句。我用下面...

using (SqlCommand cmd = new SqlCommand(query, sqlConn)) 
{ 
    cmd.Parameters.AddWithValue("@CUSTOMER", intCustomer); 
    cmd.Parameters.AddWithValue("@CONDITION", strCondition); 
    cmd.Parameters.AddWithValue("@BOOK", strBook); 
    cmd.Parameters.AddWithValue("@PAGE", strPage); 
    cmd.Parameters.AddWithValue("@ENDPAGE", strEndPage); 

    System.Diagnostics.Debug.WriteLine("Expanded query: " + 
     query.ExpandSqlQuery(cmd.Parameters)); 

    int affectedRows = cmd.ExecuteNonQuery(); 
    System.Diagnostics.Debug.WriteLine("Number of rows affected: " + affectedRows); 
} 

我曾嘗試與不只是調試PARAMS要做到這一點，總是出於某種原因獲得0返回值。

我已經提出，擴大PARAMS給我看實際的查詢（不變量）小的擴展方法...

public static string ExpandSqlQuery(this String input, SqlParameterCollection sqlParams) 
{ 
    string results = input; 

    foreach (SqlParameter p in sqlParams) 
     results = results.Replace(p.ParameterName, p.Value.ToString()); 

    return results; 
} 

...我叫權執行查詢之前，看看有什麼會被跑。

System.Diagnostics.Debug.WriteLine("Expanded query: " + 
    query.ExpandSqlQuery(cmd.Parameters)); 

然後我去，在C＃返回0受影響的行是完全相同的查詢和手動運行它Microsoft SQL Server Management Studio有它告訴我1行受到影響！

使用參數查詢是...

UPDATE 
    BookList 
SET 
    Overdue=2 
WHERE 
    Customer=@CUSTOMER 
    and Condition='@CONDITION' 
    and Book='@BOOK' 
    and Page='@PAGE' 
    and EndPage='@ENDPAGE' 
    and Overdue=1; 

UPDATE 
    BookInfo 
SET 
    Finished=0 
WHERE 
    Customer=@CUSTOMER 
    and Condition='@CONDITION' 
    and Book='@BOOK'; 

擴展查詢是...

UPDATE 
    BookList 
SET 
    Overdue=2 
WHERE 
    Customer=85 
    and Condition='old' 
    and Book='00103' 
    and Page='00304' 
    and EndPage='00304' 
    and Overdue=1; 

UPDATE 
    BookInfo 
SET 
    Finished=0 
WHERE 
    Customer=85 
    and Condition='old' 
    and Book='00103'; 

任何想法如何，我可以去調試這個問題？

Answer 1

你不能在你的參數中加引號。因此：

UPDATE 
    BookList 
SET 
    Overdue=2 
WHERE 
    Customer=@CUSTOMER 
    and Condition='@CONDITION' 
    and Book='@BOOK' 
    and Page='@PAGE' 
    and EndPage='@ENDPAGE' 
    and Overdue=1; 

UPDATE 
    BookInfo 
SET 
    Finished=0 
WHERE 
    Customer=@CUSTOMER 
    and Condition='@CONDITION' 
    and Book='@BOOK'; 

應改爲：

UPDATE 
    BookList 
SET 
    Overdue=2 
WHERE 
    Customer=@CUSTOMER 
    and Condition=@CONDITION 
    and Book=@BOOK 
    and Page=@PAGE 
    and EndPage=@ENDPAGE 
    and Overdue=1; 

UPDATE 
    BookInfo 
SET 
    Finished=0 
WHERE 
    Customer=@CUSTOMER 
    and Condition=@CONDITION 
    and Book=@BOOK;