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• Hadoop, NOSQL, and the Relational Model

  - by Phil Factor

  (Guest Editorial for the IT Pro/SysAdmin Newsletter)Whereas Relational Databases fit the world of commerce like a glove, it is useless to pretend that they are a perfect fit for all human endeavours. Although, with SQL Server, we’ve made great strides with indexing text, in processing spatial data and processing markup, there is still a problem in dealing efficiently with large volumes of ephemeral semi-structured data. Key-value stores such as Cassandra, Project Voldemort, and Riak are of great value for ephemeral data, and seem of equal value as a data-feed that provides aggregations to an RDBMS. However, the Document databases such as MongoDB and CouchDB are ideal for semi-structured data for which no fixed schema exists; analytics and logging are obvious examples. NoSQL products, such as MongoDB, tackle the semi-structured data problem with panache. MongoDB is designed with a simple document-oriented data model that scales horizontally across multiple servers. It doesn’t impose a schema, and relies on the application to enforce the data structure. This is another take on the old ‘EAV’ problem (where you don’t know in advance all the attributes of a particular entity) It uses a clever replica set design that allows automatic failover, and uses journaling for data durability. It allows indexing and ad-hoc querying. However, for SQL Server users, the obvious choice for handling semi-structured data is Apache Hadoop. There will soon be an ODBC Driver for Apache Hive .and an Add-in for Excel. Additionally, there are now two Hadoop-based connectors for SQL Server; the Apache Hadoop connector for SQL Server 2008 R2, and the SQL Server Parallel Data Warehouse (PDW) connector. We can connect to Hadoop process the semi-structured data and then store it in SQL Server. For one steeped in the culture of Relational SQL Databases, I might be expected to throw up my hands in the air in a gesture of contempt for a technology that was, judging by the overblown journalism on the subject, about to make my own profession as archaic as the Saggar makers bottom knocker (a potter’s assistant who helped the saggar maker to make the bottom of the saggar by placing clay in a metal hoop and bashing it). However, on the contrary, I find that I'm delighted with the advances made by the NoSQL databases in the past few years. Having the flow of ideas from the NoSQL providers will knock any trace of complacency out of the providers of Relational Databases and inspire them into back-fitting some features, such as horizontal scaling, with sharding and automatic failover into SQL-based RDBMSs. It will do the breed a power of good to benefit from all this lateral thinking.

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• Design for object with optional and modifiable attributtes?

  - by Ikuzen

  I've been using the Builder pattern to create objects with a large number of attributes, where most of them are optional. But up until now, I've defined them as final, as recommended by Joshua Block and other authors, and haven't needed to change their values. I am wondering what should I do though if I need a class with a substantial number of optional but non-final (mutable) attributes? My Builder pattern code looks like this: public class Example { //All possible parameters (optional or not) private final int param1; private final int param2; //Builder class public static class Builder { private final int param1; //Required parameters private int param2 = 0; //Optional parameters - initialized to default //Builder constructor public Builder (int param1) { this.param1 = param1; } //Setter-like methods for optional parameters public Builder param2(int value) { param2 = value; return this; } //build() method public Example build() { return new Example(this); } } //Private constructor private Example(Builder builder) { param1 = builder.param1; param2 = builder.param2; } } Can I just remove the final keyword from the declaration to be able to access the attributes externally (through normal setters, for example)? Or is there a creational pattern that allows optional but non-final attributes that would be better suited in this case?

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• Object inheritance and method parameters/return types - Please check my logic

  - by user2368481

  I'm preparing for a test and doing practice questions, this one in particular I am unsure I did correctly: We are given a very simple UML diagram to demonstrate inheritance: I hope this is clear, it shows that W inherits from V and so on: |-----Y V <|----- W<|-----| |-----X<|----Z and this code: public X method1(){....} method2(new Y()); method2(method1()); method2(method3()); The questions and my answers: Q: What types of objects could method1 actually return? A: X and Z, since the method definition includes X as the return type and since Z is a kind of X is would be OK to return either. Q: What could the parameter type of method2 be? A: Since method2 in the code accepts Y, X and Z (as the return from method1), the parameter type must be either V or W, as Y,X and Z inherit from both of these. Q: What could return type of method3 be? A: Return type of method3 must be V or W as this would be consistent with answer 2.

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• Tips about how to spread Object Oriented practices

  - by Augusto

  I work for a medium company that has around 250 developers. Unfortunately, lots of them are stuck in a procedural way of thinking and some teams constantly deliver big Transactional Script applications, when in fact the application contains rich logic. They also fail to manage the design dependencies, and end up with services which depend on another large number of services (a clean example of Big Ball of Mud). My question is: Can you suggest how to spread this type of knowledge? I know that the surface of the problem is that these applications have a poor architecture and design. Another issue is that there are some developers who are against writing any kind of test. A few things I'm doing to change this (but I'm either failing or the change is too small are) Running presentations about design principles (SOLID, clean code, etc). Workshops about TDD and BDD. Coaching teams (this includes using sonar, findbugs, jdepend and other tools). IDE & Refactoring talks. A few things I'm thinking to do in the future (but I'm concern that they might not be good) Form a team of OO evangelists, who disseminate an OO way of thinking in differet teams (these people would need to change teams every few months). Running design review sessions, to criticise the design and suggest improvements (even if the improvements are not done because of time constraints, I think this might be useful) . Something I found with the teams I coach, is that as soon as I leave them, they revert back to the old practices. I know I don't spend a lot of time with them, usually just one month. So whatever I'm doing, it doesn't stick. I'm sorry this question is spattered with frustration, but the alterative to write this was to hit my head on the wall until I pass out.

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• Object construction design

  - by James

  I recently started to use c# to interface with a database, and there was one part of the process that appeared odd to me. When creating a SqlCommand, the method I was lead to took the form: SqlCommand myCommand = new SqlCommand("Command String", myConnection); Coming from a Java background, I was expecting something more similar to SqlCommand myCommand = myConnection.createCommand("Command String"); I am asking, in terms of design, what is the difference between the two? The phrase "single responsibility" has been used to suggest that a connection should not be responsible for creating SqlCommands, but I would also say that, in my mind, the difference between the two is partly a mental one of the difference between a connection executing a command and a command acting on a connection, the latter of which seems less like what I have been lead to believe OOP should be. There is also a part of me wondering if the two should be completely separate, and should only come together in some sort of connection.execute(command) method. Can anyone help clear up these differences? Are any of these methods "more correct" than the others from an OO point of view? (P.S. the fact that c# is used is completely irrelevant. It just highlighted to me that different approaches were used)

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• Using visitor pattern with large object hierarchy

  - by T. Fabre

  Context I've been using with a hierarchy of objects (an expression tree) a "pseudo" visitor pattern (pseudo, as in it does not use double dispatch) : public interface MyInterface { void Accept(SomeClass operationClass); } public class MyImpl : MyInterface { public void Accept(SomeClass operationClass) { operationClass.DoSomething(); operationClass.DoSomethingElse(); // ... and so on ... } } This design was, however questionnable, pretty comfortable since the number of implementations of MyInterface is significant (~50 or more) and I didn't need to add extra operations. Each implementation is unique (it's a different expression or operator), and some are composites (ie, operator nodes that will contain other operator/leaf nodes). Traversal is currently performed by calling the Accept operation on the root node of the tree, which in turns calls Accept on each of its child nodes, which in turn... and so on... But the time has come where I need to add a new operation, such as pretty printing : public class MyImpl : MyInterface { // Property does not come from MyInterface public string SomeProperty { get; set; } public void Accept(SomeClass operationClass) { operationClass.DoSomething(); operationClass.DoSomethingElse(); // ... and so on ... } public void Accept(SomePrettyPrinter printer) { printer.PrettyPrint(this.SomeProperty); } } I basically see two options : Keep the same design, adding a new method for my operation to each derived class, at the expense of maintainibility (not an option, IMHO) Use the "true" Visitor pattern, at the expense of extensibility (not an option, as I expect to have more implementations coming along the way...), with about 50+ overloads of the Visit method, each one matching a specific implementation ? Question Would you recommand using the Visitor pattern ? Is there any other pattern that could help solve this issue ?

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• Object desing problem for simple school application

  - by Aragornx

  I want to create simple school application that provides grades,notes,presence,etc. for students,teachers and parents. I'm trying to design objects for this problem and I'm little bit confused - because I'm not very experienced in class designing. Some of my present objects are : class PersonalData() { private String name; private String surename; private Calendar dateOfBirth; [...] } class Person { private PersonalData personalData; } class User extends Person { private String login; private char[] password; } class Student extends Person { private ArrayList<Counselor> counselors = new ArrayList<>(); } class Counselor extends Person { private ArrayList<Student> children = new ArrayList<>(); } class Teacher extends Person { private ArrayList<ChoolClass> schoolClasses = new ArrayList<>(); private ArrayList<Subject> subjects = new ArrayList<>(); } This is of course a general idea. But I'm sure it's not the best way. For example I want that one person could be a Teacher and also a Parent(Counselor) and present approach makes me to have two Person objects. I want that user after successful logging in get all roles that it has (Student or Teacher or (Teacher & Parent) ). I think I should make and use some interfaces but I'm not sure how to do this right. Maybe like this: interface Role { } interface TeacherRole implements Role { void addGrade( Student student, Grade grade, [...] ); } class Teacher implements TeacherRole { private Person person; [...] } class User extends Person{ ArrayList<Role> roles = new ArrayList<>(); } Please if anyone could help me to make this right or maybe just point me to some literature/article that covers practical objects design.

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• Structuring Access Control In Hierarchical Object Graph

  - by SB2055

  I have a Folder entity that can be Moderated by users. Folders can contain other folders. So I may have a structure like this: Folder 1 Folder 2 Folder 3 Folder 4 I have to decide how to implement Moderation for this entity. I've come up with two options: Option 1 When the user is given moderation privileges to Folder 1, define a moderator relationship between Folder 1 and User 1. No other relationships are added to the db. To determine if the user can moderate Folder 3, I check and see if User 1 is the moderator of any parent folders. This seems to alleviate some of the complexity of handling updates / moved entities / additions under Folder 1 after the relationship has been defined, and reverting the relationship means I only have to deal with one entity. Option 2 When the user is given moderation privileges to Folder 1, define a new relationship between User 1 and Folder 1, and all child entities down to the grandest of grandchildren when the relationship is created, and if it's ever removed, iterate back down the graph to remove the relationship. If I add something under Folder 2 after this relationship has been made, I just copy all Moderators into the new Entity. But when I need to show only the top-level Folders that a user is Moderating, I need to query all folders that have a parent folder that the user does not moderate, as opposed to option 1, where I just query any items that the user is moderating. Thoughts I think it comes down to determining if users will be querying for all parent items more than they'll be querying child items... if so, then option 1 seems better. But I'm not sure. Is either approach better than the other? Why? Or is there another approach that's better than both? I'm using Entity Framework in case it matters.

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• ASP.NET. MVC2. Entity Framework. Cannot pass primary key value back from view to [HttpPost]

  - by Paul Connolly

  I pass a ViewModel (which contains a "Person" object) from the "EditPerson" controller action into the view. When posted back from the view, the ActionResult receives all of the Person properties except the ID (which it says is zero instead of say its real integer) Can anyone tell me why? The controllers look like this: public ActionResult EditPerson(int personID) { var personToEdit = repository.GetPerson(personID); FormationViewModel vm = new FormationViewModel(); vm.Person = personToEdit; return View(vm); } [HttpPost] public ActionResult EditPerson(FormationViewModel model) <<Passes in all properties except ID { // Persistence code } The View looks like this: <%@ Page Title="" Language="C#" MasterPageFile="~/Views/Shared/Site.Master" Inherits="System.Web.Mvc.ViewPage<Afp.Models.Formation.FormationViewModel>" %> <% using (Html.BeginForm()) {% <%= Html.ValidationSummary(true) % <fieldset> <legend>Fields</legend> <div class="editor-label"> <%= Html.LabelFor(model => model.Person.Title) %> </div> <div class="editor-field"> <%= Html.TextBoxFor(model => model.Person.Title) %> <%= Html.ValidationMessageFor(model => model.Person.Title) %> </div> <div class="editor-label"> <%= Html.LabelFor(model => model.Person.Forename)%> </div> <div class="editor-field"> <%= Html.TextBoxFor(model => model.Person.Forename)%> <%= Html.ValidationMessageFor(model => model.Person.Forename)%> </div> <div class="editor-label"> <%= Html.LabelFor(model => model.Person.Surname)%> </div> <div class="editor-field"> <%= Html.TextBoxFor(model => model.Person.Surname)%> <%= Html.ValidationMessageFor(model => model.Person.Surname)%> </div> <div class="editor-label"> <%= Html.LabelFor(model => model.DOB) %> </div> <div class="editor-field"> <%= Html.TextBoxFor(model => model.DOB, String.Format("{0:g}", Model.DOB)) <%= Html.ValidationMessageFor(model => model.DOB) %> </div>--%> <div class="editor-label"> <%= Html.LabelFor(model => model.Person.Nationality)%> </div> <div class="editor-field"> <%= Html.TextBoxFor(model => model.Person.Nationality)%> <%= Html.ValidationMessageFor(model => model.Person.Nationality)%> </div> <div class="editor-label"> <%= Html.LabelFor(model => model.Person.Occupation)%> </div> <div class="editor-field"> <%= Html.TextBoxFor(model => model.Person.Occupation)%> <%= Html.ValidationMessageFor(model => model.Person.Occupation)%> </div> <div class="editor-label"> <%= Html.LabelFor(model => model.Person.CountryOfResidence)%> </div> <div class="editor-field"> <%= Html.TextBoxFor(model => model.Person.CountryOfResidence)%> <%= Html.ValidationMessageFor(model => model.Person.CountryOfResidence)%> </div> <div class="editor-label"> <%= Html.LabelFor(model => model.Person.PreviousNameForename)%> </div> <div class="editor-field"> <%= Html.TextBoxFor(model => model.Person.PreviousNameForename)%> <%= Html.ValidationMessageFor(model => model.Person.PreviousNameForename)%> </div> <div class="editor-label"> <%= Html.LabelFor(model => model.Person.PreviousSurname)%> </div> <div class="editor-field"> <%= Html.TextBoxFor(model => model.Person.PreviousSurname)%> <%= Html.ValidationMessageFor(model => model.Person.PreviousSurname)%> </div> <div class="editor-label"> <%= Html.LabelFor(model => model.Person.Email)%> </div> <div class="editor-field"> <%= Html.TextBoxFor(model => model.Person.Email)%> <%= Html.ValidationMessageFor(model => model.Person.Email)%> </div> <p> <input type="submit" value="Save" /> </p> </fieldset> <% } % And the Person class looks like: [MetadataType(typeof(Person_Validation))] public partial class Person { public Person() { } } [Bind(Exclude = "ID")] public class Person_Validation { public int ID { get; private set; } public string Title { get; set; } public string Forename { get; set; } public string Surname { get; set; } public System.DateTime DOB { get; set; } public string Nationality { get; set; } public string Occupation { get; set; } public string CountryOfResidence { get; set; } public string PreviousNameForename { get; set; } public string PreviousSurname { get; set; } public string Email { get; set; } } And ViewModel: public class FormationViewModel { public Company Company { get; set; } public Address RegisteredAddress { get; set; } public Person Person { get; set; } public PersonType PersonType { get; set; } public int CurrentStep { get; set; } } }

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• Is learning the Caché database hard coming from relational databases and object oriented programming

  - by Edelcom

  I am currently running the local version of Caché on my system in order to determine if I can (and will) take on a new possible project. The current project uses Delphi 7 as a front end calling a Caché dll where the business logic is stored in the database. I have a background of Sqlserver and Firebird (and before Access and Paradox) as databases. I use Delphi 7 for 95% of my Windows development, so I know about object programming. I would like to recieve opinions from persons having used Caché and either SqlServer, Firebird or Oracle and having developed in Delphi (or C++ or C# - an object oriented language). I have read the pro's and con's from other questions, but I am not asking for this, I need input from Caché developers. Thanks in advance.

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• How to map a Entity Data Model conceptual model property to a storage model column using the "Serial

  - by codekaizen

  I have a conceptual model in EDM where one of the entities has a property which is essentially a big value object whose properties aren't really useful as columns in the datamodel. I'd like to apply the Serialized LOB pattern to it so that I can fit it into a 192 byte binary column. How do I map this in the EDM v4? Is it even possible at this time? Actually, is it possible in any ORM?

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• How Do I Import a 3D Object into Adobe Flex?

  - by Kim

  Hi everyone, I wanted to know if anyone here knows how to import a 3D Object (i.e. Maya 3D Model) into Adobe Flex Application? I needed to create a simple Flex application which will allow me to rotate the 3D Object by dragging but I cannot seem to start doing it because I'm having a hard time trying to figure out how I can import my 3D model into Flex. This is exactly what I wanted to do: 3D Object in Flex I hope someone can help me. Thanks a lot :)

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• LLBLGen Pro feature highlights: grouping model elements

  - by FransBouma

  (This post is part of a series of posts about features of the LLBLGen Pro system) When working with an entity model which has more than a few entities, it's often convenient to be able to group entities together if they belong to a semantic sub-model. For example, if your entity model has several entities which are about 'security', it would be practical to group them together under the 'security' moniker. This way, you could easily find them back, yet they can be left inside the complete entity model altogether so their relationships with entities outside the group are kept. In other situations your domain consists of semi-separate entity models which all target tables/views which are located in the same database. It then might be convenient to have a single project to manage the complete target database, yet have the entity models separate of each other and have them result in separate code bases. LLBLGen Pro can do both for you. This blog post will illustrate both situations. The feature is called group usage and is controllable through the project settings. This setting is supported on all supported O/R mapper frameworks. Situation one: grouping entities in a single model. This situation is common for entity models which are dense, so many relationships exist between all sub-models: you can't split them up easily into separate models (nor do you likely want to), however it's convenient to have them grouped together into groups inside the entity model at the project level. A typical example for this is the AdventureWorks example database for SQL Server. This database, which is a single catalog, has for each sub-group a schema, however most of these schemas are tightly connected with each other: adding all schemas together will give a model with entities which indirectly are related to all other entities. LLBLGen Pro's default setting for group usage is AsVisualGroupingMechanism which is what this situation is all about: we group the elements for visual purposes, it has no real meaning for the model nor the code generated. Let's reverse engineer AdventureWorks to an entity model. By default, LLBLGen Pro uses the target schema an element is in which is being reverse engineered, as the group it will be in. This is convenient if you already have categorized tables/views in schemas, like which is the case in AdventureWorks. Of course this can be switched off, or corrected on the fly. When reverse engineering, we'll walk through a wizard which will guide us with the selection of the elements which relational model data should be retrieved, which we can later on use to reverse engineer to an entity model. The first step after specifying which database server connect to is to select these elements. below we can see the AdventureWorks catalog as well as the different schemas it contains. We'll include all of them. After the wizard completes, we have all relational model data nicely in our catalog data, with schemas. So let's reverse engineer entities from the tables in these schemas. We select in the catalog explorer the schemas 'HumanResources', 'Person', 'Production', 'Purchasing' and 'Sales', then right-click one of them and from the context menu, we select Reverse engineer Tables to Entity Definitions.... This will bring up the dialog below. We check all checkboxes in one go by checking the checkbox at the top to mark them all to be added to the project. As you can see LLBLGen Pro has already filled in the group name based on the schema name, as this is the default and we didn't change the setting. If you want, you can select multiple rows at once and set the group name to something else using the controls on the dialog. We're fine with the group names chosen so we'll simply click Add to Project. This gives the following result:   (I collapsed the other groups to keep the picture small ;)). As you can see, the entities are now grouped. Just to see how dense this model is, I've expanded the relationships of Employee: As you can see, it has relationships with entities from three other groups than HumanResources. It's not doable to cut up this project into sub-models without duplicating the Employee entity in all those groups, so this model is better suited to be used as a single model resulting in a single code base, however it benefits greatly from having its entities grouped into separate groups at the project level, to make work done on the model easier. Now let's look at another situation, namely where we work with a single database while we want to have multiple models and for each model a separate code base. Situation two: grouping entities in separate models within the same project. To get rid of the entities to see the second situation in action, simply undo the reverse engineering action in the project. We still have the AdventureWorks relational model data in the catalog. To switch LLBLGen Pro to see each group in the project as a separate project, open the Project Settings, navigate to General and set Group usage to AsSeparateProjects. In the catalog explorer, select Person and Production, right-click them and select again Reverse engineer Tables to Entities.... Again check the checkbox at the top to mark all entities to be added and click Add to Project. We get two groups, as expected, however this time the groups are seen as separate projects. This means that the validation logic inside LLBLGen Pro will see it as an error if there's e.g. a relationship or an inheritance edge linking two groups together, as that would lead to a cyclic reference in the code bases. To see this variant of the grouping feature, seeing the groups as separate projects, in action, we'll generate code from the project with the two groups we just created: select from the main menu: Project -> Generate Source-code... (or press F7 ;)). In the dialog popping up, select the target .NET framework you want to use, the template preset, fill in a destination folder and click Start Generator (normal). This will start the code generator process. As expected the code generator has simply generated two code bases, one for Person and one for Production: The group name is used inside the namespace for the different elements. This allows you to add both code bases to a single solution and use them together in a different project without problems. Below is a snippet from the code file of a generated entity class. //... using System.Xml.Serialization; using AdventureWorks.Person; using AdventureWorks.Person.HelperClasses; using AdventureWorks.Person.FactoryClasses; using AdventureWorks.Person.RelationClasses; using SD.LLBLGen.Pro.ORMSupportClasses; namespace AdventureWorks.Person.EntityClasses { //... /// <summary>Entity class which represents the entity 'Address'.<br/><br/></summary> [Serializable] public partial class AddressEntity : CommonEntityBase //... The advantage of this is that you can have two code bases and work with them separately, yet have a single target database and maintain everything in a single location. If you decide to move to a single code base, you can do so with a change of one setting. It's also useful if you want to keep the groups as separate models (and code bases) yet want to add relationships to elements from another group using a copy of the entity: you can simply reverse engineer the target table to a new entity into a different group, effectively making a copy of the entity. As there's a single target database, changes made to that database are reflected in both models which makes maintenance easier than when you'd have a separate project for each group, with its own relational model data. Conclusion LLBLGen Pro offers a flexible way to work with entities in sub-models and control how the sub-models end up in the generated code.

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• SQL SERVER – Error: Fix – Msg 208 – Invalid object name ‘dbo.backupset’ – Invalid object name ‘dbo.backupfile’

  - by pinaldave

  Just a day before I got a very interesting email. Here is the email (modified a bit to make it relevant to this blog post). “Pinal, We are facing a very strange issue. One of our query  related to backup files and backup set has stopped working suddenly in SSMS. It works fine in application where we have and in the stored procedure but when we have it in our SSMS it gives following error. Msg 208, Level 16, State 1, Line 1 Invalid object name ‘dbo.backupfile’. Here are our queries which we are trying to execute. SELECT name, database_name, backup_size, TYPE, compatibility_level, backup_set_id FROM dbo.backupset; SELECT logical_name, backup_size, file_type FROM dbo.backupfile; This query gives us details related to backupset and backup files when the backup was taken.” When I receive this kind of email, usually I have no answers directly. The claim that it works in stored procedure and in application but not in SSMS gives me no real data. I have requested him to very first check following two things: If he is connected to correct server? His answer was yes. If he has enough permissions? His answer was he was logged in as an admin. This means there was something more to it and I requested him to send me a screenshot of the his SSMS. He promptly sends that to me and as soon as I receive the screen shot I knew what was going on. Before I say anything take a look at the screenshot yourself and see if you can figure out why his queries are not working in SSMS. Just to make your life a bit easy, I have already given a hint in the image. The answer is very simple, the context of the database is master database. To execute above two queries the context of the database has to be msdb. Tables backupset and backupfile belong to the database msdb only. Here are two workaround or solution to above problem: 1) Change context to MSDB Above two queries when they will run as following they will not error out and will give the accurate desired result. USE msdb GO SELECT name, database_name, backup_size, TYPE, compatibility_level, backup_set_id FROM dbo.backupset; SELECT logical_name, backup_size, file_type FROM dbo.backupfile; 2) Prefix the query with msdb There are cases above script used in stored procedure or part of big query, it is not possible to change the context of the whole query to any specific database. Use three part naming convention and prefix them with msdb. SELECT name, database_name, backup_size, TYPE, compatibility_level, backup_set_id FROM msdb.dbo.backupset; SELECT logical_name, backup_size, file_type FROM msdb.dbo.backupfile; Very simple solution but sometime keeps people wondering for an answer. Reference: Pinal Dave (http://blog.sqlauthority.com) Filed under: PostADay, SQL, SQL Authority, SQL Error Messages, SQL Query, SQL Server, SQL Tips and Tricks, T SQL, Technology

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• Soapi.CS : A fully relational fluent .NET Stack Exchange API client library

  - by Sky Sanders

  Soapi.CS for .Net / Silverlight / Windows Phone 7 / Mono as easy as breathing...: var context = new ApiContext(apiKey).Initialize(false); Question thisPost = context.Official .StackApps .Questions.ById(386) .WithComments(true) .First(); Console.WriteLine(thisPost.Title); thisPost .Owner .Questions .PageSize(5) .Sort(PostSort.Votes) .ToList() .ForEach(q=> { Console.WriteLine("\t" + q.Score + "\t" + q.Title); q.Timeline.ToList().ForEach(t=> Console.WriteLine("\t\t" + t.TimelineType + "\t" + t.Owner.DisplayName)); Console.WriteLine(); }); // if you can think it, you can get it. Output Soapi.CS : A fully relational fluent .NET Stack Exchange API client library 21 Soapi.CS : A fully relational fluent .NET Stack Exchange API client library Revision code poet Revision code poet Votes code poet Votes code poet Revision code poet Revision code poet Revision code poet Votes code poet Votes code poet Votes code poet Revision code poet Revision code poet Revision code poet Revision code poet Revision code poet Revision code poet Revision code poet Revision code poet Revision code poet Revision code poet Votes code poet Comment code poet Revision code poet Votes code poet Revision code poet Revision code poet Revision code poet Answer code poet Revision code poet Revision code poet 14 SOAPI-WATCH: A realtime service that notifies subscribers via twitter when the API changes in any way. Votes code poet Revision code poet Votes code poet Comment code poet Comment code poet Comment code poet Votes lfoust Votes code poet Comment code poet Comment code poet Comment code poet Comment code poet Revision code poet Comment lfoust Votes code poet Revision code poet Votes code poet Votes lfoust Votes code poet Revision code poet Comment Dave DeLong Revision code poet Revision code poet Votes code poet Comment lfoust Comment Dave DeLong Comment lfoust Comment lfoust Comment Dave DeLong Revision code poet 11 SOAPI-EXPLORE: Self-updating single page JavaSript API test harness Votes code poet Votes code poet Votes code poet Votes code poet Votes code poet Comment code poet Revision code poet Votes code poet Revision code poet Revision code poet Revision code poet Comment code poet Revision code poet Votes code poet Comment code poet Question code poet Votes code poet 11 Soapi.JS V1.0: fluent JavaScript wrapper for the StackOverflow API Comment George Edison Comment George Edison Comment George Edison Comment George Edison Comment George Edison Comment George Edison Answer George Edison Votes code poet Votes code poet Votes code poet Votes code poet Revision code poet Revision code poet Answer code poet Comment code poet Revision code poet Comment code poet Comment code poet Comment code poet Revision code poet Revision code poet Votes code poet Votes code poet Votes code poet Votes code poet Comment code poet Comment code poet Comment code poet Comment code poet Comment code poet 9 SOAPI-DIFF: Your app broke? Check SOAPI-DIFF to find out what changed in the API Votes code poet Revision code poet Comment Dennis Williamson Answer Dennis Williamson Votes code poet Votes Dennis Williamson Comment code poet Question code poet Votes code poet About A robust, fully relational, easy to use, strongly typed, end-to-end StackOverflow API Client Library. Out of the box, Soapi provides you with a robust client library that abstracts away most all of the messy details of consuming the API and lets you concentrate on implementing your ideas. A few features include: A fully relational model of the API data set exposed via a fully 'dot navigable' IEnumerable (LINQ) implementation. Simply tell Soapi what you want and it will get it for you. e.g. "On my first question, from the author of the first comment, get the first page of comments by that person on any post" my.Questions.First().Comments.First().Owner.Comments.ToList(); (yes this is a real expression that returns the data as expressed!) Full coverage of the API, all routes and all parameters with an intuitive syntax. Strongly typed Domain Data Objects for all API data structures. Eager and Lazy Loading of 'stub' objects. Eager\Lazy loading may be disabled. When finer grained control of requests is desired, the core RouteMap objects may be leveraged to request data from any of the API paths using all available parameters as documented on the help pages. A rich Asynchronous implementation. A configurable request cache to reduce unnecessary network traffic and to simplify your usage logic. There is no need to go out of your way to be frugal. You may set a distinct cache duration for any particular route. A configurable request throttle to ensure compliance with the api terms of usage and to simplify your code in that you do not have to worry about and respond to 50X errors. The RequestCache and Throttled Queue are thread-safe, so can make as many requests as you like from as many threads as you like as fast as you like and not worry about abusing the api or having to write reams of management/compensation code. Configurable retry threshold that will, by default, make up to 3 attempts to retrieve a request before failing. Every request made by Soapi is properly formed and directed so most any http error will be the result of a timeout or other network infrastructure. A retry buffer provides a level of fault tolerance that you can rely on. An almost identical javascript library, Soapi.JS, and it's full figured big brother, Soapi.JS2, that will enable you to leverage your server cycles and bandwidth for only those tasks that require it and offload things like status updates to the client's browser. License Licensed GPL Version 2 license. Why is Soapi.CS GPL? Can I get an LGPL license for Soapi.CS? (hint: probably) Platforms .NET 3.5 .NET 4.0 Silverlight 3 Silverlight 4 Windows Phone 7 Mono Download Source code lives @ http://soapics.codeplex.com. Binary releases are forthcoming. codeplex is acting up again. get the source and binaries @ http://bitbucket.org/bitpusher/soapi.cs/downloads The source is C# 3.5. and includes projects and solutions for the following IDEs Visual Studio 2008 Visual Studio 2010 ModoDevelop 2.4 Documentation Full documentation is available at http://soapi.info/help/cs/index.aspx Sample Code / Usage Examples Sample code and usage examples will be added as answers to this question. Full API Coverage all API routes are covered Full Parameter Parity If the API exposes it, Soapi giftwraps it for you. Building a simple app with Soapi.CS - a simple app that gathers all traces of a user in the whole stackiverse. Fluent Configuration - Setting up a Soapi.ApiContext could not be easier Bulk Data Import - A tiny app that quickly loads a SQLite data file with all users in the stackiverse. Paged Results - Soapi.CS transparently handles multi-page operations. Asynchronous Requests - Soapi.CS provides a rich asynchronous model that is especially useful when writing api apps in Silverlight or Windows Phone 7. Caching and Throttling - how and why Apps that use Soapi.CS Soapi.FindUser - .net utility for locating a user anywhere in the stackiverse Soapi.Explore - The entire API at your command Soapi.LastSeen - List users by last access time Add your app/site here - I know you are out there ;-) if you are not comfortable editing this post, simply add a comment and I will add it. The CS/SL/WP7/MONO libraries all compile the same code and with the exception of environmental considerations of Silverlight, the code samples are valid for all libraries. You may also find guidance in the test suites. More information on the SOAPI eco-system. Contact This library is currently the effort of me, Sky Sanders (code poet) and can be reached at gmail - sky.sanders Any who are interested in improving this library are welcome. Support Soapi You can help support this project by voting for Soapi's Open Source Ad post For more information about the origins of Soapi.CS and the rest of the Soapi eco-system see What is Soapi and why should I care?

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• Changing Recovery Model in Replicated Database

  - by Rob

  I now am the proud owner of two servers that replicate with each other. I had nothing to do with the install, but (of course), now i have to support the databases. Both databases are in the Simple recovery model, but the users want to ensure as little data loss as possible so I'm thinking that I should change the recovery model over to full and start doing transaction log backups. I wasn't planning on backing up the subscribing database, only the publisher. Is this the right plan? Do I need to switch both the Subscriber and and the publisher to Full, or can I leave the subscriber in Simple, but have the Publisher in Full? When I change the recovery model in one (or both) do the databases need to be offline? Thanks

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• .Net MVC UserControl - Form values not mapped to model

  - by Andreas

  Hi I have a View that contains a usercontrol. The usercontrol is rendered using: <% Html.RenderPartial("GeneralStuff", Model.General, ViewData); %> My problem is that the usercontrol renders nicely with values from the model but when I post values edited in the usercontrol they are not mapped back to Model.General. I know I can find the values in Request.Form but I really thought that MVC would manage to map these values back to the model. My usercontrol: <%@ Control Language="C#" Inherits="System.Web.Mvc.ViewUserControl<namespace.Models.GeneralViewModel>" %> <fieldset> <div> <%= Html.LabelFor(model => model.Value)%> <%= Html.TextBoxFor(model => model.Value)%> </div> </fieldset> I'm using .Net MVC 2 Thanks for any help!

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• Define "Validation in the Model"

  - by sunwukung

  There have been a couple of discussions regarding the location of user input validation: http://stackoverflow.com/questions/659950/should-validation-be-done-in-form-objects-or-the-model http://stackoverflow.com/questions/134388/where-do-you-do-your-validation-model-controller-or-view These discussions were quite old, so I wanted to ask the question again to see if anyone had any fresh input. If not, I apologise in advance. If you come from the Validation in the Model camp - does Model mean OOP representation of data (i.e. Active Record/Data Mapper) as "Entity" (to borrow the DDD terminology) - in which case you would, I assume, want all Model classes to inherit common validation constraints. Or can these rules simply be part of a Service in the Model - i.e. a Validation service? For example, could you consider Zend_Form and it's validation classes part of the Model? The concept of a Domain Model does not appear to be limited to Entities, and so validation may not necessarily need to be confined to this Entities. It seems that you would require a lot of potentially superfluous handing of values and responses back and forth between forms and "Entities" - and in some instances you may not persist the data recieved from user input, or recieve it from user input at all.

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• Persisting model state in ASP.NET MVC using Serialize HTMLHelper

  - by shiju

  ASP.NET MVC 2 futures assembly provides a HTML helper method Serialize that can be use for persisting your model object. The Serialize  helper method will serialize the model object and will persist it in a hidden field in the HTML form. The Serialize  helper is very useful when situations like you are making multi-step wizard where a single model class is using for all steps in the wizard. For each step you want to retain the model object's whole state.The below is serializing our model object. The model object should be a Serializable class in order to work with Serialize helper method. <% using (Html.BeginForm("Register","User")) {%><%= Html.Serialize("User",Model) %> This will generate hidden field with name "user" and the value will the serialized format of our model object.In the controller action, you can place the DeserializeAttribute in the action method parameter. [HttpPost]               public ActionResult Register([DeserializeAttribute] User user, FormCollection userForm) {     TryUpdateModel(user, userForm.ToValueProvider());     //To Do } In the above action method you will get the same model object that you serialized in your view template. We are updating the User model object with the form field values.

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• Persisting model state in ASP.NET MVC using Serialize HTMLHelper

  - by shiju

  ASP.NET MVC 2 futures assembly provides a HTML helper method Serialize that can be use for persisting your model object. The Serialize  helper method will serialize the model object and will persist it in a hidden field in the HTML form. The Serialize  helper is very useful when situations like you are making multi-step wizard where a single model class is using for all steps in the wizard. For each step you want to retain the model object's whole state.The below is serializing our model object. The model object should be a Serializable class in order to work with Serialize helper method. <% using (Html.BeginForm("Register","User")) {%><%= Html.Serialize("User",Model) %> This will generate hidden field with name "user" and the value will the serialized format of our model object.In the controller action, you can place the DeserializeAttribute in the action method parameter. [HttpPost]               public ActionResult Register([DeserializeAttribute] User user, FormCollection userForm) {     TryUpdateModel(user, userForm.ToValueProvider());     //To Do } In the above action method you will get the same model object that you serialized in your view template. We are updating the User model object with the form field values.

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• Best practices concerning view model and model updates with a subset of the fields

  - by Martin

  By picking MVC for developing our new site, I find myself in the midst of "best practices" being developed around me in apparent real time. Two weeks ago, NerdDinner was my guide but with the development of MVC 2, even it seems outdated. It's an thrilling experience and I feel privileged to be in close contact with intelligent programmers daily. Right now I've stumbled upon an issue I can't seem to get a straight answer on - from all the blogs anyway - and I'd like to get some insight from the community. It's about Editing (read: Edit action). The bulk of material out there, tutorials and blogs, deal with creating and view the model. So while this question may not spell out a question, I hope to get some discussion going, contributing to my decision about the path of development I'm to take. My model represents a user with several fields like name, address and email. All the names, in fact, on field each for first name, last name and middle name. The Details view displays all these fields but you can change only one set of fields at a time, for instance, your names. The user expands a form while the other fields are still visible above and below. So the form that is posted back contains a subset of the fields representing the model. While this is appealing to us and our layout concerns, for various reasons, it is to be shunned by serious MVC-developers. I've been reading about some patterns and best practices and it seems that this is not in key with the paradigm of viewmodel == view. Or have I got it wrong? Anyway, NerdDinner dictates using FormCollection och UpdateModel. All the null fields are happily ignored. Since then, the MVC-community has abandoned this approach to such a degree that a bug in MVC 2 was not discovered. UpdateModel does not work without a complete model in your formcollection. The view model pattern receiving most praise seems to be Dedicated view model that contains a custom view model entity and is the only one that my design issue could be made compatible with. It entails a tedious amount of mapping, albeit lightened by the use of AutoMapper and the ideas of Jimmy Bogard, that may or may not be worthwhile. He also proposes a 1:1 relationship between view and view model. In keeping with these design paradigms, I am to create a view and associated view for each of my expanding sets of fields. The view models would each be nearly identical, differing only in the fields which are read-only, the views also containing much repeated markup. This seems absurd to me. In future I may want to be able to display two, more or all sets of fields open simultaneously. I will most attentively read the discussion I hope to spark. Many thanks in advance.

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• rotating model around own Y-axis XNA

  - by ChocoMan

  I'm have trouble with my model rotating around it's own Y-axis. The model is a person. When I test my world, the model is loaded at a position of 0, 0, 0. When I rotate my model from there, the model rotates like normal. The problem comes AFTER I moved the model to a new position. If I move the the model forward, left, etc, then try to rotate it on it's own Y-Axis, the model will rotate, but still around the original position in a circular manner (think of yourself swing around on a rope, but always facing outward from the center). Does anyone know how to keep the center point of rotation updated?

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• How to make an object stay relative to another object

  - by Nick

  In the following example there is a guy and a boat. They have both a position, orientation and velocity. The guy is standing on the shore and would like to board. He changes his position so he is now standing on the boat. The boat changes velocity and orientation and heads off. My character however has a velocity of 0,0,0 but I would like him to stay onboard. When I move my character around, I would like to move as if the boat was the ground I was standing on. How do keep my character aligned properly with the boat? It is exactly like in World Of Warcraft, when you board a boat or zeppelin. This is my physics code for the guy and boat: this.velocity.addSelf(acceleration.multiplyScalar(dTime)); this.position.addSelf(this.velocity.clone().multiplyScalar(dTime)); The guy already has a reference to the boat he's standing on, and thus knows the boat's position, velocity, orientation (even matrices or quaternions can be used).

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• Problem with updating data in asp .NET MVC 2 application

  - by Bojan

  Hello everyone, i am just getting started with asp .NET MVC 2 applications and i stumbled upon a problem. I'm having trouble updating my tables. The debugger doesn't report any error, it just doesn't do anything... I hope some can help me out. Thank you for your time. This is my controller code... public ActionResult Edit(int id) { var supplierToEdit = (from c in _entities.SupplierSet where c.SupplierId == id select c).FirstOrDefault(); return View(supplierToEdit); } // // POST: /Supplier/Edit/5 [AcceptVerbs(HttpVerbs.Post)] public ActionResult Edit(Supplier supplierToEdit) { if (!ModelState.IsValid) return View(); try { var originalSupplier = (from c in _entities.SupplierSet where c.SupplierId == supplierToEdit.SupplierId select c).FirstOrDefault(); _entities.ApplyPropertyChanges(originalSupplier.EntityKey.EntitySetName, supplierToEdit); _entities.SaveChanges(); // TODO: Add update logic here return RedirectToAction("Index"); } catch { return View(); } } This is my View ... <h2>Edit</h2> <% using (Html.BeginForm()) {%> <%= Html.ValidationSummary(true) %> <fieldset> <legend>Fields</legend> <div class="editor-label"> <%= Html.LabelFor(model => model.CompanyName) %> </div> <div class="editor-field"> <%= Html.TextBoxFor(model => model.CompanyName) %> <%= Html.ValidationMessageFor(model => model.CompanyName) %> </div> <div class="editor-label"> <%= Html.LabelFor(model => model.ContactName) %> </div> <div class="editor-field"> <%= Html.TextBoxFor(model => model.ContactName) %> <%= Html.ValidationMessageFor(model => model.ContactName) %> </div> <div class="editor-label"> <%= Html.LabelFor(model => model.ContactTitle) %> </div> <div class="editor-field"> <%= Html.TextBoxFor(model => model.ContactTitle) %> <%= Html.ValidationMessageFor(model => model.ContactTitle) %> </div> <div class="editor-label"> <%= Html.LabelFor(model => model.Address) %> </div> <div class="editor-field"> <%= Html.TextBoxFor(model => model.Address) %> <%= Html.ValidationMessageFor(model => model.Address) %> </div> <div class="editor-label"> <%= Html.LabelFor(model => model.City) %> </div> <div class="editor-field"> <%= Html.TextBoxFor(model => model.City) %> <%= Html.ValidationMessageFor(model => model.City) %> </div> <div class="editor-label"> <%= Html.LabelFor(model => model.PostalCode) %> </div> <div class="editor-field"> <%= Html.TextBoxFor(model => model.PostalCode) %> <%= Html.ValidationMessageFor(model => model.PostalCode) %> </div> <div class="editor-label"> <%= Html.LabelFor(model => model.Country) %> </div> <div class="editor-field"> <%= Html.TextBoxFor(model => model.Country) %> <%= Html.ValidationMessageFor(model => model.Country) %> </div> <div class="editor-label"> <%= Html.LabelFor(model => model.Telephone) %> </div> <div class="editor-field"> <%= Html.TextBoxFor(model => model.Telephone) %> <%= Html.ValidationMessageFor(model => model.Telephone) %> </div> <div class="editor-label"> <%= Html.LabelFor(model => model.Fax) %> </div> <div class="editor-field"> <%= Html.TextBoxFor(model => model.Fax) %> <%= Html.ValidationMessageFor(model => model.Fax) %> </div> <div class="editor-label"> <%= Html.LabelFor(model => model.HomePage) %> </div> <div class="editor-field"> <%= Html.TextBoxFor(model => model.HomePage) %> <%= Html.ValidationMessageFor(model => model.HomePage) %> </div> <p> <input type="submit" value="Save" /> </p> </fieldset> <% } %> <div> <%= Html.ActionLink("Back to List", "Index") %> </div>

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• How attach a model with another model on a specific bone?

  - by Mehdi Bugnard

  I meet a difficulty attached to a model to another model on a "bone" accurate. I searched several forums but no result. I saw that many people have asked the same question but no real result see no response. Thread found : How to attach two XNA models together? How can I attach a model to the bone of another model? http://stackoverflow.com/questions/11391852/attach-model-xna But I think it is possible. Here is my code example attached a "cube" of the hand of my player private void draw_itemActionAttached(Model modelInUse) { Matrix[] Model1TransfoMatrix = new Matrix[this.player.Model.Bones.Count]; this.player.Model.CopyAbsoluteBoneTransformsTo(Model1TransfoMatrix); foreach (ModelMesh mesh in modelInUse.Meshes) { foreach (BasicEffect effect in mesh.Effects) { Matrix model2Transform = Matrix.CreateScale(1f) * Matrix.CreateFromYawPitchRoll(0, 0, 0); effect.World = model2Transform * Model1TransfoMatrix[0]; //root bone index effect.View = arcadia.camera.View; effect.Projection = arcadia.camera.Projection; } mesh.Draw(); } }

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