从字符串转换datetime时转换失败

Question

我正在开发一个C#VS 2008/SQL Server 2005 Express网站应用程序.我已经尝试了一些针对这个问题的修复,但是我的调用栈与其他问题不同.而这些修复并没有解决我的问题.我可以采取哪些步骤来解决这个问题？

这是我的错误:

System.Data.SqlClient.SqlException was caught
  Message="Conversion failed when converting datetime from character string."
  Source=".Net SqlClient Data Provider"
  ErrorCode=-2146232060

  LineNumber=10
  Number=241
  Procedure="AppendDataCT"
  Server="\\\\.\\pipe\\772EF469-84F1-43\\tsql\\query"
  State=1
  StackTrace:
       at System.Data.SqlClient.SqlConnection.OnError(SqlException exception, Boolean breakConnection)
       at System.Data.SqlClient.SqlInternalConnection.OnError(SqlException exception, Boolean breakConnection)
       at System.Data.SqlClient.TdsParser.ThrowExceptionAndWarning(TdsParserStateObject stateObj)
       at System.Data.SqlClient.TdsParser.Run(RunBehavior runBehavior, SqlCommand cmdHandler, SqlDataReader dataStream, BulkCopySimpleResultSet bulkCopyHandler, TdsParserStateObject stateObj)
       at System.Data.SqlClient.SqlCommand.FinishExecuteReader(SqlDataReader ds, RunBehavior runBehavior, String resetOptionsString)
       at System.Data.SqlClient.SqlCommand.RunExecuteReaderTds(CommandBehavior cmdBehavior, RunBehavior runBehavior, Boolean returnStream, Boolean async)
       at System.Data.SqlClient.SqlCommand.RunExecuteReader(CommandBehavior cmdBehavior, RunBehavior runBehavior, Boolean returnStream, String method, DbAsyncResult result)
       at System.Data.SqlClient.SqlCommand.InternalExecuteNonQuery(DbAsyncResult result, String methodName, Boolean sendToPipe)
       at System.Data.SqlClient.SqlCommand.ExecuteNonQuery()
       at ADONET_namespace.ADONET_methods.AppendDataCT(DataTable dt, Dictionary`2 dic) in c:\Documents and Settings\Admin\My Documents\Visual Studio 2008\WebSites\Jerry\App_Code\ADONET methods.cs:line 102

这是相关的代码.当我调试这段代码时,"dic"只循环遍历3列名,但没有查看存储在"dt"数据表中的行值.

public static string AppendDataCT(DataTable dt, Dictionary<string, string> dic)
{
    if (dic.Count != 3)
        throw new ArgumentOutOfRangeException("dic can only have 3 parameters");

    string connString = ConfigurationManager.ConnectionStrings["AW3_string"].ConnectionString;
    string errorMsg;

    try
    {               
        using (SqlConnection conn2 = new SqlConnection(connString))
        {
            using (SqlCommand cmd = conn2.CreateCommand())
            {
                cmd.CommandText = "dbo.AppendDataCT";
                cmd.CommandType = CommandType.StoredProcedure;
                cmd.Connection = conn2;
                foreach (string s in dic.Keys)
                {
                    SqlParameter p = cmd.Parameters.AddWithValue(s, dic[s]);
                    p.SqlDbType = SqlDbType.VarChar;
                }

                conn2.Open();
                cmd.ExecuteNonQuery();
                conn2.Close();
                errorMsg = "The Person.ContactType table was successfully updated!";
            }
        }
    }

这是我的SQL存储过程:

ALTER PROCEDURE [dbo].[AppendDataCT] 
@col1 VARCHAR(50), 
@col2 VARCHAR(50),
@col3 VARCHAR(50)
AS
BEGIN
SET NOCOUNT ON;
DECLARE @TEMP DATETIME
SET @TEMP = (SELECT CONVERT (DATETIME, @col3))

INSERT INTO Person.ContactType (Name, ModifiedDate)
VALUES( @col2, @TEMP)
END

输入文件有3列.前两个是varchars,但第三个也是我认为的varchar,但它表示为"3/11/2010".在此输入文件中,示例行如下所示:"Benjamin | breakfast | 3/11/2010".我正在尝试将此日期字段从字符串转换为我的SP中的日期时间.我是以错误的方式去做的吗？

DataRow:col1 | col2 | col3 11 | A2 | 1/10/1978 12 | b2 | 2/10/1978 13 | c2 | 3/10/1978 14 | d2 | 4/10/1978

Answer 1

我认为Belousov Pavel是正确的.在foreach中,您将每个字典项目指定为参数.这些参数中的每一个都被定义为VarChar.通过提供的信息,可以合理地假设问题出在存储过程中.

您可以发布存储过程的代码,也可以尝试通过在那里执行存储过程来重新创建SQL Management Studio中的错误.

更新中...

查看存储过程后,代码看起来正确.我能够使用以下sql代码生成您获得的错误消息.

声明@col3 varchar(50)

设置@ col3 ='| 3/11/2010'

声明@temp datetime

设置@temp =(选择转换(datetime,@ col3))

请注意,@ col3的值以管道符开头.如果删除管道字符,它可以正常工作.

我会仔细查看字典中您从中获取参数值的值.解析数据的方式可能存在问题.

更新2

以下代码未确认可行,但我想我知道您要做的是什么.我假设你传入的DataTable有这样的数据:

col1 | col2 | col3 11 | A2 | 1/10/1978 12 | b2 | 2/10/1978 13 | c2 | 3/10/1978 14 | d2 | 4/10/1978

如果是这种情况,我们不需要最初传入的字典.我还可以假设您希望对DataTable中的每一行执行一次存储过程.下面的方法类似于你在做什么,虽然它运行每行的存储过程.

我不能确定你解释的是DataTable的第一行是否包含列的名称,如果不是没有担心的话.希望这是有道理的,如果您有疑问,请留下更多评论.

    public static string TestMethod(DataTable dt)
    {
        string connString = "";
        string errorMsg = string.Empty;

        try
        {
            //loop through each row of the datatable. Not sure if the column names is a row.
            foreach (DataRow row in dt.Rows)
            {
                using (SqlConnection conn2 = new SqlConnection(connString))
                {
                    using (SqlCommand cmd = conn2.CreateCommand())
                    {
                        cmd.CommandText = "dbo.AppendDataCT";
                        cmd.CommandType = CommandType.StoredProcedure;
                        cmd.Connection = conn2;

                        cmd.Parameters.Add(new SqlParameter() { ParameterName = "@col1", SqlDbType = SqlDbType.VarChar, Value = row[0] });
                        cmd.Parameters.Add(new SqlParameter() { ParameterName = "@col2", SqlDbType = SqlDbType.VarChar, Value = row[1] });
                        cmd.Parameters.Add(new SqlParameter() { ParameterName = "@col3", SqlDbType = SqlDbType.VarChar, Value = row[2] });

                        conn2.Open();
                        cmd.ExecuteNonQuery();
                        conn2.Close();
                    }
                }                
            }
            errorMsg = "The Person.ContactType table was successfully updated!";
        }
        catch
        {
        }

        return errorMsg;
    }