参数化动态SQL语句

Question

当我运行以下代码时，我收到一个错误：“必须声明标量变量”@objString“”。我可以不参数化动态SQL语句吗？有没有更好的写作方式？我有它工作，但它涉及动态插入名称和 userID 这显然是一个安全问题，因为该信息是从最终用户网页传入的。我想参数化这两个值以避免SQL注入问题。

    private void setValue(Object obj, String name)
    {
        SqlConnection sqlConnection = SQLConnections.GetPortalConnection();
        String sqlStatement = String.Empty;
        string[] parameterNames;
        string[] parameters;

        switch (obj.GetType().ToString())
        {
            case "System.String":
                string objString = obj.ToString();
                sqlStatement = @"
                                declare @name nvarchar(" + name.Length + @");
                                declare @sql nvarchar(4000); 
                                SET @name = '" + name + @"';
                                SET @sql = 'UPDATE [myoc4Data].[dbo].[users] SET ' + @name + ' = @objString WHERE [UserID] = @userID;'
                                exec sp_executesql @sql;";
                string[] parameterNames = { "@objString", "@userID" };
                string[] parameters = { objString, this.userID };
                break;
            default:
                throw new Exception("Person.Portal.UserProfile.setValue: object type not found");
        }

        SQLConnections.ExecuteNonQuery(sqlStatement, parameterNames, parameters, sqlConnection);
        sqlConnection.Close();
    }

...

    public static void ExecuteNonQuery(String sqlStatement, string[] parameterNames, object[] parameters, SqlConnection sqlConnection)
    {
        // Parameterized query
        try
        {
            SqlCommand sqlCommand = sqlConnection.CreateCommand();
            sqlCommand = new SqlCommand(sqlStatement, sqlConnection);
            for (int x = 0; x < parameters.Length; x++)
            {
                switch (Type.GetTypeCode(parameters[x].GetType()))
                {
                    case TypeCode.DateTime:
                        sqlCommand.Parameters.Add(parameterNames[x], SqlDbType.DateTime).Value = ((DateTime)parameters[x]).Year < 1753 ? DBNull.Value : parameters[x];
                        continue;
                }
                sqlCommand.Parameters.Add(new SqlParameter(parameterNames[x], parameters[x]));
            }
            sqlCommand.ExecuteNonQuery();
        }
        catch (Exception ex)
        {
            throw new System.ArgumentException("Exception: Person: SQLConnections: Could not execute SQL statement: " + ex.Message);
        }
    }