Question

我这样做：

var command = new SqlCommand(query, myConnection);
                foreach (DataRow row in dt.Rows)
                {
                    query = @"update FileLog set
                    FaxStatus=" + "'" + row.ItemArray[0].ToString() + "'," +
                    "FaxedPageCount=" + "'" + row.ItemArray[1].ToString() + "'," +
                    "dtFaxed=" + "'" + row.ItemArray[2].ToString() + "'," +
                    "RetryCount=" + "'" + row.ItemArray[4].ToString() + "' " +
                    "where JobID=" + "'" + row.ItemArray[3].ToString() + "'";
                    command = new SqlCommand(query, myConnection);
                   command.ExecuteNonQuery();

                }

JobID是uniqueidentifier

我收到了这个错误：

Conversion failed when converting from a character string to uniqueidentifier.

我做错了什么？

JobID字段如下所示：

DB9424E5-1E73-4108-A855-B252E516A2A2
2EB17B8B-C0A1-46FE-82AF-37AEF2A8A6EC
C24F0460-7667-4A3A-8D8F-64B9728C2359
8DCDB020-8C7B-493E-9D21-719CBAFC16B6

Answer 1

这将更安全（从SQL注入安全），更易于阅读和理解，并且更快，因为准备好的语句可以缓存其执行计划。如果你有不同的sql，它就不能使用缓存的执行计划。

     SqlCommand cmd =
        new SqlCommand(
           @"update FileLog set FaxStatus=@fs, FaxedPageCount=@ct, @dtFaxed=@dt, ......., where JobID=@id")
        {CommandType = CommandType.Text};
     cmd.Prepare();
     cmd.Connection = connection;
     cmd.Parameters["@id"].Value = row.ItemArray[0];
     ...

Answer 2

我找到了解决方案。结果你需要这样做：

                var command = new SqlCommand(query, myConnection);
                foreach (DataRow row in dt.Rows)
                {
                    query = @"update FileLog set
                    FaxStatus=" + "'" + row.ItemArray[0].ToString() + "'," +
                    "FaxedPageCount=" + "'" + row.ItemArray[1].ToString() + "'," +
                    "dtFaxed=" + "'" + row.ItemArray[2].ToString() + "'," +
                    "BiscomCode=" + "'" + row.ItemArray[5].ToString() + "', " +
                    "RetryCount=" + "'" + row.ItemArray[4].ToString() + "' " +
                    "where CONVERT(VARCHAR(255), JobID) =" + "'" + row.ItemArray[3].ToString() + "'";
                    command = new SqlCommand(query, myConnection);
                   command.ExecuteNonQuery();

                }

你必须先将它转换为varchar

Answer 3

您的工作ID很可能不是有效的Guid。

这是检查guid的方法：

    public static bool IsGuid(string input)
    {
        Regex isGuid = new Regex(@"^(\{){0,1}[0-9a-fA-F]{8}\-[0-9a-fA-F]{4}\-[0-9a-fA-F]{4}\-[0-9a-fA-F]{4}\-[0-9a-fA-F]{12}(\}){0,1}$", RegexOptions.Compiled);
        try
        {
            return isGuid.IsMatch(input);
        }
        catch
        {
            return false;
        }
    }

因此，在发出查询命令之前，请检查jobid。如果它不匹配，请将其转义并将其记录下来以便稍后重新访问。

SQL c＃更新表

3 个答案: