DotNetAddicted

2022-01-02T14:06:00.001+00:00

Q1. What is WCF?

WCF stands for Windows Communication Foundation. It is a Software development kit for developing services on Windows. WCF is introduced in .NET 3.0. in the System.ServiceModel namespace. WCF is based on basic concepts of Service oriented architecture (SOA)

Q2. What is endpoint in WCF service?
The endpoint is an Interface which defines how a client will communicate with the service. It consists of three main points: Address, Binding and Contract.

Q3. Explain Address, Binding, and contract for a WCF Service?
Address: Address defines where the service resides.
Binding: Binding defines how to communicate with the service.
Contract: Contract defines what is done by the service.

Q4. What is the various address format in WCF?
a) HTTP Address Format: --> http://localhost:
b) TCP Address Format: --> net.tcp://localhost:
c) MSMQ Address Format: --> net.msmq://localhost:

Q5. What are the types of binding available in WCF?
A binding is identified by the transport it supports and the encoding it uses. Transport may be HTTP, TCP etc. and encoding may be text, binary etc. The popular types of binding may be as below:
a) BasicHttpBinding
b) NetTcpBinding
c) WSHttpBinding
d) NetMsmqBinding

Q6. What are the types of contract available in WCF?
The main contracts are:
a) Service Contract: Describes what operations the client can perform.
b) Operation Contract: defines the method inside Interface of Service.
c) Data Contract: Defines what data types are passed
d) Message Contract: Defines whether a service can interact directly with messages

Q7. What are the various ways of hosting a WCF Service?
a) IIS b) Self Hosting c) WAS (Windows Activation Service)

Q8. What is the proxy for WCF Service?
A proxy is a class by which a service client can Interact with the service.
Using proxy in the client application we are able to call the different methods exposed by the service

Q9. How can we create Proxy for the WCF Service?
We can create proxy using the tool svcutil.exe after creating the service.
We can use the following command at command line.
svcutil.exe *.wsdl *.xsd /language:C# /out:SampleProxy.cs /config:app.config

Q10.What is the difference between WCF Service and Web Service?
a) WCF Service supports both http and TCP protocol while webservice supports only http protocol.
b) WCF Service is more flexible than web service.

Q11.What is Data Contract and Service Contract? Explain 
Data represented by creating Data Contract which expose the
data which will be transferred /consumed from the service
to its clients.

**Operations which is the functions provided by this
service.

To write an operation on WCF, you must write it as an
interface, this interface contains the "Signature" of the
methods tagged by ServiceContract attribute, and all methods
signature will be implemented on this interface tagged with
OperationContract attribute.

and to implement these service contract you must create
a class which implement the interface and the actual
implementation will be on that class.

Code Below show How to create a Service Contract:

Code:

[ServiceContract]
Public Interface IEmpOperations
{
[OperationContract]
Decimal Get EmpSal(int EmpId);

}

Class MyEmp: IEmpOperations
{
Decimal Get EmpSal()
{
// Implementation of this method.
}
}

SharePoint 2010 Questions And Answers

2012-05-29T10:11:00.000+01:00

SharePoint Architecture Questions

1) What are Web Applications in SharePoint?

An IIS Web site created and used by SharePoint 2010. Saying an IIS virtual server is also an acceptable answer.

2) What is an application pool?

A group of one or more URLs that are served by a particular worker process or set of worker processes.

3) Why are application pools important?

They provide a way for multiple sites to run on the same server but still have their own worker processes and identity.

4) What are Web Application Policies?

Enables security policy for users at the Web application level, rather than at the site collection or site level. Importantly, they override all other security settings.

5) What are zones?

Different logical paths (URLs meaning) of gaining access to the same SharePoint Web application.

6) What is a site collection?

A site collection contains a top-level website and can contain one or more sub-sites web sites that have the same owner and share administration settings.

7) What are content databases?

A content database can hold all the content for one or more site collections.

8) What is a site?

A site in SharePoint contains Web pages and related assets such as lists, all hosted within a site collection.

9) What are My Sites?

Specialized SharePoint sites personalized and targeted for each user.

10) What is the difference between Classic mode authentication and Claims-based authentication?

As the name implies, classic authentication supports NT authentication types like Kerberos, NTLM, Basic, Digest, and anonymous. Claims based authentication uses claims identities against a against a trusted identity provider.

11) When would you use claims, and when would you use classic?

Classic is more commonly seen in upgraded 2007 environments whereas claims are the recommended path for new deployments.

12) Describe the potential components for both a single server, and multiple servers, potentially several tiered farms:

A single-server SharePoint Server 2010 environment leverages a built-in SQL Server 2008 Express database. The problems with this environment is scalability, not being able to install the with built-in database on a domain controller, the database cannot be larger than 4 GB, and you cannot use User Profile Synchronization in a single server with built-in database installation.

An example of a multiple tier farm would be a three-tier topology, considered one of the more efficient physical and logical layouts to supports scaling out or scaling up and provides better distribution of services across the member servers of the farm. This is considered a good architecture since one can add Web servers to the Web tier, add app servers to the application tier, and add database servers to the database tier.

SharePoint Backup and Restore Questions

13) What are some of the tools that can be used when backing up a SharePoint 2010 environment?

SharePoint farm backup and recovery
SQL Server
System Center Data Protection Manager

14) What Microsoft tool can be used for incremental backups?

System Center Data Protection Manager

Managed Metadata Questions

15) What is Managed Metadata?

Managed metadata is a hierarchical collection of centrally managed terms that you can define, and then use as attributes for items.

16) What are Terms and Term Sets?

A term is a word or a phrase that can be associated with an item. A term set is a collection of related terms.

17) How do Terms And Term Sets relate to Managed Metadata?

Managed metadata is a way of referring to the fact that terms and term sets can be created and managed independently from the columns themselves.

18) Are there different types of Term Sets?

There are Local Term Sets and Global Term Sets, one created within the context of a site collection and the other created outside the context of a site collection, respectively.

19) How are terms created and used?

There are several ways; however the most common is to use the Term Store Management Tool.

20) How is Managed Metadata, and the related Term technology used?

Through the UI, the most common use is through the managed metadata list column which allows you to specify the term set to use. It also related to searching and enhancing the user search experience.

Sandbox Solutions Questions

21) What is a sandboxed solution?

Components that are deployed to run within the sandboxed process rather than running in the production Internet Information Services (IIS) worker process.

22) What are some examples of things that might run within the SharePoint sandbox?

Any of the following are acceptable answers:

Web Parts
Event receivers
Feature receivers
Custom Microsoft SharePoint Designer workflow activities
Microsoft InfoPath business logic

others….

23) Why are sandboxed solutions used?

Primarily because they promote high layers of isolation. By default they run within a rights-restricted, isolated process based around Code Access Security (CAS). Isolation is possible to increase with activities like running the sandboxing service on only specific SharePoint 2010 servers.

SharePoint Search Questions

24) What is a content source in relation to SharePoint search? What’s the minimum amount of content sources?

A content source is a set of options that you can use to specify what type of content is crawled, what URLs to crawl, and how deep and when to crawl. You must create at least one content source before a crawl can occur.

25) What is a search scope?

A search scope defines a subset of information in the search index. Users can select a search scope when performing a search.

26) What is a federated location with SharePoint search?

Federated locations provide information that exists outside of your internal network to your end-users.

27) How does managed metadata affect search?

Enhances the end-user search experience by mapping crawled properties to managed properties. Managed properties show up in search results and help users perform more successful queries.

28) What is query logging in SharePoint 2010?

Collects information about user search queries and search results that users select on their computers to improve the relevancy of search results and to improve query suggestions.

29) What authentication type does the SharePoint crawler use?

The crawl component requires access to content using NTLM authentication.

Services Architecture Questions

30) Please describe what a Service Application is in SharePoint 2010.

Service applications in SharePoint 2010 are a set of services that can possibly be shared across Web applications. Some of these services may or may not be shared across the SharePoint 2010 farm. The reason these applications are shared is the overall reduction of resources required to supply the functionality these services cultivate.

31) Please provide an example of one of these service applications.

Any of the below are acceptable answers:

Access Services
Business Data Connectivity service
Excel Services Application
Managed Metadata service
PerformancePoint Service Application
Search service
Secure Store Service
State service
Usage and Health Data Collection service
User Profile service
Visio Graphics Service
Web Analytics service
Word Automation Services
Microsoft SharePoint Foundation Subscription Settings Service

32) What are Service Application Groups used for?

Just provides a logical grouping of services that are scoped to a particular Web Application.

33) How are Service Applications deployed in terms of IIS (Internet Information Services)?

They are provisioned as a single Internet Information Services (IIS) Web site.

34) Explain how connections are managed with Service Applications.

A virtual entity is used that is referred to as a proxy, due to label in PowerShell.

35) What are some common examples of SharePoint 2010 services architectures, and what are the advantages of each design?

The three most popular designs are single farms with either a single service application group or multiple service application groups, or Enterprise services farms.

Single farms with a single service application group are generally the most common, and have the advantages of easy deployment, simple service application allocation, effective resource utilization and cohesive management.

Single farms with multiple service application groups is less common, and have the advantage of potential individual management of service applications as well as allowing data isolation, and while being more complex to deploy and maintain allows targeting of sites to particular service applications.

Enterprise Service Farms is pretty uncommon as it is a complete farm dedicated to Service Applications but promotes autonomous management and high levels of data isolation.

36) Are there any other type of relevant service architectures?

Depending on the environment requirements, a specialized farm can also be used in order to deploy specific services tailored to the organizational requirements which can aid in scaling out and conservation of resources.

37) What is the User Profile service?

Allows configuring and managing User profile properties, Audiences, Profile synchronization settings, organization browsing and management settings, and My Site settings.

38) What are User Profiles?

Aggregates properties from diverse identity content sources together to create unified and consistent profiles across an organization, used throughout the SharePoint environment.

39) What is Excel Services?

Allows sharing, securing, managing, and using Excel 2010 workbooks in a SharePoint Server Web site or document library. Excel Services consists of the Excel Calculation Services (ECS), Microsoft Excel Web Access (EWA), and Excel Web Services (EWS) components.

40) What is PerformancePoint Services?

Allows users to monitor and analyze a business by building dashboards, scorecards, and key performance indicators (KPIs).

41) What is Visio Services?

Allows users to share and view Microsoft Visio Web drawings. The service also enables data-connected Microsoft Visio 2010 Web drawings to be refreshed and updated from various data sources.

42) What is Access Services?

Allows users to edit, update, and create linked Microsoft Access 2010 databases that can be viewed and manipulated by using an internet browser, the Access client, or a linked HTML page.

43) What is the Secure Store Service (SSS)?

A secure database for storing credentials that are associated with application IDs

44) What is Content Deployment?

Content deployment enables you to copy content from a source site collection to a destination site collection.

Backup / DR Questions

45) Describe how redundancy can be built into a SharePoint environment. Please be specific in regards to any auxiliary components.

Multiple front-end web servers (WFE’s) can be deployed and correlated through Windows NLB or anything approach. Application servers can be deployed into the farm for a variety of purposes, depending on organizational requirements. Databases can be clustered or mirrored, again depending on requirements and environment.

46) From a basic standpoint, what is the difference between SQL clustering and mirroring?

Clustering provides a failover scenario whereby one or more nodes can be swapped as active depending on whether a node goes down. In mirroring, transactions are sent directly from a principal database and server to a mirror database to establish essentially a replica of the database.

Governance Questions

47) What Is Governance in terms of SharePoint 2010?

Governance is the set of policies, roles, responsibilities, and processes that guide, direct, and control how an organization’s business divisions and IT teams cooperate to achieve business goals.

48) What are some useful, OOB features of SharePoint that aid with governance of an environment?

Any of the below are acceptable answers. There are some others but these are the major ones that I generally look for from a candidate:

Site templates – consistent branding, site structure, and layout can be enforce a set of customizations that are applied to a site definition.

Quotas – limits to the amount of storage a site collection can use.

Locks - prevent users from either adding content to a site collection or using the site collection.

Web application permissions and policies – comprehensive security settings that apply to all users and groups for all site collections within a Web application.

Self-service site creation - enables users to create their own site collections, thus must be incorporated into a governance scheme.

Monitoring Questions

49) Describe the monitoring features that are baked into SharePoint 2010.

Diagnostic logging captures data about the state of the system, whereas health and usage data collection uses specific timer jobs to perform monitoring tasks, collecting information about:

Performance Counter Fata
Event Log Data
Timer Service Data
Metrics For Site Collections and Sites
Search Usage Data

General Workflow Questions

50) What is a declarative workflow? Can non-authenticated users participate in workflows?

Workflows created by using Microsoft SharePoint Designer 2010, the default setting enables deployment of declarative workflows. Yes, however you do not give non-authorized users access to the site. The e-mail message and attachments sent from notifications might contain sensitive information.

C# .Net Interview Questions

2012-05-25T14:49:00.002+01:00

1. Which is better - singly linked list or doubly linked list? What are the pros and cons of using each?
Answer -

It depends on the requirement.Single linked list has smaller memory requirement because it needs only forward reference. If you need to get next item from a specified item, then you should use single list. It can be traversed in forward direction only.

When you need to get previous or next item from a specified item then doubly linked is the best option. It can be traversed in both directions.

2. What's the difference between Managed code and Native code?

Answer -

Managed Code - Managed code is the code which runs under .Net CLR. CLR basically take care of Exception handling, memory management, Code access security, etc. It is not compiled directly to machine code , but to an intermediate language.

Native code: Code which is complied directly to machine code. It is executed by OS directly. It always has chances of memory leak if developer has not handled it properly. Unlike CLR, There is no garbage collection and no memory management.

3. What is thread safe code?

Answer -

In multithreaded application where multiple threads call the same method of the object. Then there should be synchronization mechanism so that one thread can not interrupt other thread. If this situation is not synchronized, then one thread might interrupt another thread and the object could be left in an invalid state. A class whose members are protected from such interruptions is called thread-safe.

2012-05-25T12:55:00.000+01:00

C# Interview Questions & Answers

Question 1: Write a function that receives three integer inputs for the lengths of the sides of a triangle and returns one of four values to determine the triangle type (1=scalene, 2=isosceles, 3=equilateral, 4=error). Generate test cases for the function assuming another developer coded the function.

Answer :

int GetCubicType(int Height, int Width, int Length)

{

if (Height < 0 || Width < 0 || Length < 0)

return 4;

else

{

if ((Height == Width) && (Height == Length))

return 3;

else

if ((Height == Width) || (Width == Length) || (Length == Width))

return 2;

else

return 1;

}

Question 2: Implement a circular queue of integers of user-specified size using a simple array. Provide routines to initialize(), enqueue() and dequeue() the queue. Make it thread safe.

Answer :

using System;

using System.Collections.Generic;

using System.Linq;

using System.Text;

namespace ThreadSafeCirculurQueue

{

class ThreadSafeCircularQueue

{

private int[] _queue;

private int _length;

private int _head;

private int _tail;

private static object _objLocker = new object();

public ThreadSafeCircularQueue()

{

Initialize();

}

private void Initialize()

{

_head = -1;

_tail = -1;

Console.Write("Please enter queue size: ");

string length = Console.ReadLine();

int queueLength = 0;

bool success = int.TryParse(length, out queueLength);

if(!success){

Console.Write("Invalid Data\n PleaseTry Again");

return;

}

_length = queueLength;

_queue = new int[_length];

}

private void Enqueue(int data)

{

lock (_objLocker)

{

if ((_head == 0 && _tail == _length - 1) ||

(_tail + 1 == _head))

{

Console.WriteLine("Queue is full.");

return;

}

else

{

if (_tail == _length - 1)

_tail = 0;

else

_tail++;

_queue[_tail] = data;

Console.WriteLine("Inserted Item --> {0}", data);

}

if (_head == -1)

_head = 0;

}

private void Dequeue()

{

lock (_objLocker)

{

int data;

if (_head == -1)

{

Console.WriteLine("Queue is empty.");

data = -1;

}

else

{

data = _queue[_head];

_queue[_head] = 0;

if (_head == _tail)

_head = _tail = -1;

else

if (_head == _length - 1)

_head = 0;

else

_head++;

Console.WriteLine("Removed Item --> {0}", data);

}

private void ShowData()

{

lock (_objLocker)

{

int i;

if (_head == -1)

{

Console.WriteLine("Queue is empty.");

return;

}

else

{

if (_tail < _head)

{

for (i = 0; i <= _length - 1; i++)

Console.Write("{0} ", _queue[i]);

}

else

{

for (i = 0; i <= _tail; i++)

Console.Write("{0} ", _queue[i]);

}

Console.WriteLine();

}

public void EnqueueDequeue()

{

for (int i = 1; i < 5; i++)

{

Enqueue(i);

}

ShowData();

Enqueue(5); // Circular queue is full!

for(int i = 1; i <5;i++)

{

Dequeue();

}

Dequeue(); // Circular queue is empty!

ShowData();

Enqueue(6);

ShowData();

Enqueue(7);

ShowData();

Dequeue();

Enqueue(8);

ShowData();

Enqueue(9);

ShowData();

Enqueue(10);

ShowData();

}

class Program

{

static void Main(string[] args)

{

ThreadSafeCircularQueue circularQueue =

new ThreadSafeCircularQueue();

Thread[] threads = new Thread[1]; // Thread can be increased

for (int i = 0; i < threads.Length; i++)

{

threads[i] =

new Thread(new ThreadStart(circularQueue.EnqueueDequeue));

}

for (int i = 0; i < threads.Length; i++)

{

threads[i].Start();

}

Console.ReadLine();

}

The art of staying in the present | Specials | Cricinfo Magazine | Cricinfo.com

2009-07-30T14:15:00.000+01:00

The art of staying in the present | Specials | Cricinfo Magazine | Cricinfo.com

Insert datatable into SQL Server using Bulk Copy

2009-04-10T11:53:00.000+01:00

Here is code
//create Sql connection
//create Sql command

//tablename is the name of table in database
source is the datatable

using (SqlBulkCopy bulkCopy = new SqlBulkCopy(conneection , SqlBulkCopyOptions.Default, command.Transaction))
{
bulkCopy.DestinationTableName = tablename;
bulkCopy.NotifyAfter = 1000;
bulkCopy.BulkCopyTimeout = 100;
bulkCopy.WriteToServer(source);
bulkCopy.Close();
}

PropertyGrid

2008-06-14T07:59:00.000+01:00

PropertyGrid

Six C# features Java developers will kill for...

2008-06-06T06:36:00.000+01:00

Six C# features Java developers will kill for...

Using GetHashCode and Equals

2008-06-06T06:10:00.000+01:00

The ability to override GetHashCode is available on every object but is seldom required for POCOs. The Equals method usually provides all of the comparison functionality we'll ever need. But when using an ORM such as NHibernate, GetHashCode takes a more prominent role as it helps NHibernate determine if an object already exists in a collection. Not overriding GetHashCode, or doing so inappropriately, may lead to duplicate objects showing up in collections and/or objects missing altogether. When needed, most people implement both methods and end up with similar code in both. So to ease the burden of managing both of these methods, there's exploitable overlap between Equals and GetHashCode to kill two birds with one stone.

In my project work, I consider the following to be true when comparing two objects:

* If two objects have IDs, and have the same IDs, then they may be considered equal without examining them further. (I'm assuming ID to be an identity field, or equivalent, in the DB.)
* If two objects have IDs, but have different IDs, than they may be considered not equal without examining them further. E.g., If customer A has an ID of 4 while customer B has an ID of 5, then they are not equal, QED.
* If neither object has an ID or only one of them has an ID, but their "business value signatures" are identical, then they're equal. E.g., customer A has an ID of 4 and a social-security-number of 123-45-6789 while customer B has no ID but also has a social-security-number of 123-45-6789. In this case, customer A and customer B are equal. By "business signatures," I imply a combination of those properties which deem an entity unique, regardless of its ID.

* If one of them is null, then they are not equal. (Whoo, that was easy.)

With the above considerations in mind, we'll want to write code to make the following unit test pass. Note that Customer takes a company name into its constructor. It also has a settable contact name. The combination of its company name and contact name give Customer its unique business signature.

view plaincopy to clipboardprint?

1. [Test]
2. public void CanCompareCustomers() {
3. Customer customerA = new Customer("Acme");
4. Customer customerB = new Customer("Anvil");
5.
6. Assert.AreNotEqual(customerA, null);
7. Assert.AreNotEqual(customerA, customerB);
8.
9. customerA.SetIdTo(1);
10. customerB.SetIdTo(1);
11.
12. // Even though the signatures are different,
13. // the persistent IDs were the same. Call me
14. // crazy, but I put that much trust into IDs.
15. Assert.AreEqual(customerA, customerB);
16.
17. Customer customerC = new Customer("Acme");
18.
19. // Since customerA has an ID but customerC
20. // doesn't, their signatures will be compared
21. Assert.AreEqual(customerA, customerC);
22.
23. customerC.ContactName = "Coyote";
24.
25. // Signatures are now different
26. Assert.AreNotEqual(customerA, customerC);
27.
28. // customerA.Equals(customerB) because they
29. // have the same ID.
30. // customerA.Equals(customerC) because they
31. // have the same signature.
32. // customerB.DoesNotEquals(customerC) because
33. // we can't compare their IDs, since
34. // customerC is transient, and their
35. // signatures are different.
36. Assert.AreNotEqual(customerB, customerC);
37. }

[Test] public void CanCompareCustomers() { Customer customerA = new Customer("Acme"); Customer customerB = new Customer("Anvil"); Assert.AreNotEqual(customerA, null); Assert.AreNotEqual(customerA, customerB); customerA.SetIdTo(1); customerB.SetIdTo(1); // Even though the signatures are different, // the persistent IDs were the same. Call me // crazy, but I put that much trust into IDs. Assert.AreEqual(customerA, customerB); Customer customerC = new Customer("Acme"); // Since customerA has an ID but customerC // doesn't, their signatures will be compared Assert.AreEqual(customerA, customerC); customerC.ContactName = "Coyote"; // Signatures are now different Assert.AreNotEqual(customerA, customerC); // customerA.Equals(customerB) because they // have the same ID. // customerA.Equals(customerC) because they // have the same signature. // customerB.DoesNotEquals(customerC) because // we can't compare their IDs, since // customerC is transient, and their // signatures are different. Assert.AreNotEqual(customerB, customerC); }

Although some argue against a single object which all other persistable domain objects inherit from, I use one nonetheless and ingeniously call it "DomainObject." (Those are Dr. Evil quotes there.) "DomainObject," in its entirety, contains the following:

view plaincopy to clipboardprint?

1. public abstract class DomainObject
2. {
3. ///

4. /// ID may be of type string, int,
5. /// custom type, etc.
6. ///

7. public IdT ID {
8. get { return id; }
9. }
10.
11. public override sealed bool Equals(object obj) {
12. DomainObject compareTo =
13. obj as DomainObject;
14.
15. return (compareTo != null) &&
16. (HasSameNonDefaultIdAs(compareTo) ||
17. // Since the IDs aren't the same, either
18. // of them must be transient to compare
19. // business value signatures
20. (((IsTransient()) || compareTo.IsTransient()) &&
21. HasSameBusinessSignatureAs(compareTo)));
22. }
23.
24. ///

25. /// Transient objects are not associated with an
26. /// item already in storage. For instance, a
27. /// Customer is transient if its ID is 0.
28. ///

29. public bool IsTransient() {
30. return ID == null || ID.Equals(default(IdT));
31. }
32.
33. ///

34. /// Must be implemented to compare two objects
35. ///

36. public abstract override int GetHashCode();
37.
38. private bool HasSameBusinessSignatureAs(DomainObject compareTo) {
39. return GetHashCode().Equals(compareTo.GetHashCode());
40. }
41.
42. ///

43. /// Returns true if self and the provided domain
44. /// object have the same ID values and the IDs
45. /// are not of the default ID value
46. ///

47. private bool HasSameNonDefaultIdAs(DomainObject compareTo) {
48. return (ID != null &&
49. ! ID.Equals(default(IdT))) &&
50. (compareTo.ID != null &&
51. ! compareTo.ID.Equals(default(IdT))) &&
52. ID.Equals(compareTo.ID);
53. }
54.
55. ///

56. /// Set to protected to allow unit tests to set
57. /// this property via reflection and to allow
58. /// domain objects more flexibility in setting
59. /// this for those objects with assigned IDs.
60. ///

61. protected IdT id = default(IdT);
62. }

public abstract class DomainObject { ///

/// ID may be of type string, int, /// custom type, etc. ///

public IdT ID { get { return id; } } public override sealed bool Equals(object obj) { DomainObject compareTo = obj as DomainObject; return (compareTo != null) && (HasSameNonDefaultIdAs(compareTo) || // Since the IDs aren't the same, either // of them must be transient to compare // business value signatures (((IsTransient()) || compareTo.IsTransient()) && HasSameBusinessSignatureAs(compareTo))); } ///

/// Transient objects are not associated with an /// item already in storage. For instance, a /// Customer is transient if its ID is 0. ///

public bool IsTransient() { return ID == null || ID.Equals(default(IdT)); } ///

/// Must be implemented to compare two objects ///

public abstract override int GetHashCode(); private bool HasSameBusinessSignatureAs(DomainObject compareTo) { return GetHashCode().Equals(compareTo.GetHashCode()); } ///

/// Returns true if self and the provided domain /// object have the same ID values and the IDs /// are not of the default ID value ///

private bool HasSameNonDefaultIdAs(DomainObject compareTo) { return (ID != null && ! ID.Equals(default(IdT))) && (compareTo.ID != null && ! compareTo.ID.Equals(default(IdT))) && ID.Equals(compareTo.ID); } ///

/// Set to protected to allow unit tests to set /// this property via reflection and to allow /// domain objects more flexibility in setting /// this for those objects with assigned IDs. ///

protected IdT id = default(IdT); }

Note that Equals is sealed and cannot be overridden by a DomainObject implementation. I suppose it could be unsealed, but since I put a lot of work into that method, I don't want anyone mucking it up!

Now assume that Customer implements DomainObject. As mentioned above, the combination of its company name and contact name give it its unique signature. So its GetHashCode would be as follows:

view plaincopy to clipboardprint?

1. public override int GetHashCode() {
2. return (GetType().FullName + "|" +
3. CompanyName + "|" +
4. ContactName).GetHashCode();
5. }

public override int GetHashCode() { return (GetType().FullName + "|" + CompanyName + "|" + ContactName).GetHashCode(); }

You'll notice that the start of the method includes the full name of the class type itself. With this in place, two different classes would never return the same signature. (You'll have to reconsider how GetHashCode is implemented to handle inheritance structures; e.g. a Customer and an Employee both inherit from a Person class but Customer and Employee may be equal in some instances...for this, I'd probably only add GetHashCode to the Person class.) Additionally, note that GetHashCode should only contain the "business signature" of the object and not include its ID. Including the ID in the signature would make it impossible to find equality between a transient object and a ! transient object. (Equality for all regardless of transience I say!)

Pramod Gupta

Bulk Binding: FORALL

2008-05-22T06:54:00.000+01:00

Bulk Binding: FORALL
When writing your PL/SQL stored procedure bear in mind that SQL statements are still sent to the SQL Engine as opposed to the PL/SQL Engine. Therefore in cases where you are executing several SQL statements in a loop, the resulting context switches could cause a noticeable performance problem.

One solution to this performance solution is the use of "bulk binding." What is that? Well first, you may recall that binding variables allows you to tie the current value of a variable into an SQL statement.
http://thinkoracle.blogspot.com/2005/06/bind-variables-in-plsql.html

"Bulk Binding" refers to a process whereby you can tie the current values of all the elements in an entire collection into a single operation. By using bulk binds, only one context switch is made between the PL/SQL and SQL Engines, to pass the entire collection, thus avoiding those performance issues.

So how is this done? In this case, using FORALL.

Let's look at an example from the Oracle documentation of how you might do something without any knowledge of bulk binding:

DECLARE
TYPE NumList IS VARRAY(20) OF NUMBER;
depts NumList := NumList(10,30,70);
BEGIN
FOR i IN depts.FIRST..depts.LAST LOOP
UPDATE emp SET sal = sal + 100 WHERE deptno = depts(i);
END LOOP;
END;

Using timing techniques I've explained before, here is what I came up with:
http://thinkoracle.blogspot.com/2005/09/analyzing-query-performance.html

call count cpu elapsed disk query
------- ------ -------- ---------- ---------- ----------
Parse 1 0.00 0.00 0 0
Execute 3 0.01 0.00 0 9
Fetch 0 0.00 0.00 0 0
------- ------ -------- ---------- ---------- ----------
total 4 0.01 0.00 0 9

Instead, we can use FORALL like this:

DECLARE
TYPE NumList IS VARRAY(20) OF NUMBER;
depts NumList := NumList(10,30,70);
BEGIN
FORALL i IN depts.FIRST..depts.LAST
UPDATE emp SET sal = sal + 100 WHERE deptno = depts(i);
END;

And get this:

call count cpu elapsed disk query
------- ------ -------- ---------- ---------- ----------
Parse 1 0.00 0.00 0 0
Execute 1 0.00 0.01 0 9
Fetch 0 0.00 0.00 0 0
------- ------ -------- ---------- ---------- ----------
total 2 0.00 0.01 0 9

Notice 1 execute instead of 3. Of course we won't see any performance difference on a small sample size, but here I am just illustrating the point.

You may notice the absense of the keyword "LOOP" in the FORALL example. That is because despite its similar appearances and syntax in this example, FORALL is not a loop. It takes a single SQL statement, and the index i can be used only as an index into the collection.

You can find more information about FORALL in the PL/SQL User's Guide and Reference: http://download-west.oracle.com/docs/cd/B10501_01/appdev.920/a96624.pdf

Another useful trick is the use of SQL%BULK_ROWCOUNT (SQL is the implicit cursor used by the SQL engine for DML operations). It can be indexed the same way as the collection.

DECLARE
TYPE NumList IS VARRAY(20) OF NUMBER;
depts NumList := NumList(10,30,70);
BEGIN
FORALL i IN depts.FIRST..depts.LAST
UPDATE emp SET sal = sal + 100 WHERE deptno = depts(i);

FOR i IN depts.FIRST..depts.LAST LOOP
DBMS_OUTPUT.PUT_LINE('Affected Rows for ' || depts(i) || ' is ' || SQL%BULK_ROWCOUNT(i));
END LOOP;
END;

Affected Rows for 10 is 3
Affected Rows for 30 is 6
Affected Rows for 70 is 0

The only error I can foresee getting with FORALL is this one:
ORA-22160: element at index does not exist
And you will only get that if you are somehow binding to an index that does not exist.

You may also get complaints if you use the index in an expression, which is not supported:
PLS-00430: FORALL iteration variable i is not allowed in this context

Now that I've spoken about avoiding unnecessary context switches executing SQL statements, what about unnecessary context switches in getting information FROM the SQL engine? Are those avoidable? Yes, using BULK COLLECT. I'll write more about that shortly.

Links:
Dan Morgan has more than just a reference on this topic, he has lots of really good examples: http://www.psoug.org/reference/bulk_collect.html

There is also a short but good write-up on bulk binding in the Application Developer's Guide: Fundamentals, look under Chapter 9:
http://download-west.oracle.com/docs/cd/B10501_01/appdev.920/a96590.pdf

Dr. Tim Hall has some several good write-ups with good examples: http://www.oracle-base.com/articles/8i/BulkBinds8i.php

CodeProject: Database. Free source code and programming help

2008-05-08T11:52:00.000+01:00

CodeProject: Database. Free source code and programming help

SQL Server 2005 | New XML Capabilities

2008-05-06T13:38:00.000+01:00

SQL Server 2005 | New XML Capabilities: "Take Five with SQL Server 2005"

Take Five with SQL Server 2005

2008-05-06T13:36:00.000+01:00

Take Five with SQL Server 2005

New XML Capabilities in SQL Server 2005
Kevin S. Goff, Microsoft MVP 2007

This is the first installment in a monthly, ten-part series on new developer features in SQL Server 2005. The objective of this series is to provide software developers with quick information and meaningful examples that demonstrate new capabilities in SQL 2005. Many developers can testify that being able to effectively utilize the tools in SQL Server can increase the value they bring to a software project. This series will cover the following:

New XML capabilities (subject of this article)
A three-part series on new T-SQL 2005 language features
SQL Server 2005 Service Broker
SQL Server 2005 Isolation Levels
A two-part series on writing procedures and functions in the .NET CLR, and in-process data access
SQL Server 2005 Reporting Services
ADO.NET

The title of this series ("Take Five with SQL 2005") reflects the goal of providing useful programming examples in a short period of time. Despite a number of great SQL 2005 books, some developers don’t always have time to study the material in a book. So these articles will focus on code samples that developers can adapt to their applications.

So let’s begin! Microsoft beefed up support of XML in SQL 2005. Here are the items we’ll cover:

The new XML datatype in SQL 2005, and the new associated methods (query, exists, value, and nodes)
A reusable T-SQL UDF to convert XML to a table variable
New SELECT FOR….XML capabilities
Performing partial text searches inside an XML DataColumn

1- XML Datatype and associated methods:

Prior to SQL Server 2005, if developers wanted to convert XML data to relational data, they had to use combinations of the stored procedure sp_xml_preparedocument and the OPENXML function. While still valid, this methodology introduces some overhead. SQL 2005 provides native support for the XML data type, and new methods to directly parse and read the data.

Listing A provides a demonstration. The code creates a basic XML string of names and cities, and uses the nodes method to create a row for each instance of the Customer node. We must provide a table/column name combination to use the results, so we’ll call it tab(col). In the SELECT statement, the code will use the value method to strip out pieces of the tab(col) structure. Finally, the query uses the exist method, which evaluates a comparison condition and returns either a 0 or 1. Note that the syntax for exist doesn’t allow us to concatenate a search variable – but we can use the sql:variable syntax to embed any variable or parameter.

Listing A
(using nodes to convert XML to relational data)

-- using the XML Nodes methd to turn XML data

-- into Relational Data

DECLARE @XMLString XML

SET @XMLString ='

Kevin

Goff

Camp Hill

Steve

Goff

Philadelphia

-- use the basic query method

SELECT @XMLString.query('/Customers/Customer')

-- Now query using the nodes method

-- Read the columns using the value method, and set a condition using exist

-- Set a search condition

DECLARE @cLookup VARCHAR(50)

SET @cLookup ='Camp Hill'

SELECT

tab.col.value('FirstName[1]','VARCHAR(20)')AS FirstName,

tab.col.value('LastName[1]','VARCHAR(20)')AS LastName,

tab.col.value('City[1]','VARCHAR(20)')AS City

FROM @XMLString.nodes('//Customer') tab(col)

WHERE tab.col.exist('City/text()[.= sql:variable("@cLookup")] ')= 1

2 - A reusable T-SQL UDF to convert XML to a table variable

Many database applications execute queries based on a variable number of selections. For example, a product report might prompt the user with a menu of dozens or even hundreds of products. The user selects any number of products, and the database must query against the information for those products.

Over the years, developers have come up with different ways to write a stored procedure that accepts a variable number of selections. Some developers will pass a comma-delimited string of integer PK values representing the selections, write a UDF in T-SQL to convert the string to a table variable, and then query against the table variable. Other developers will pass an XML string of selections, and then use sp_xml_preparedocument and OPENXML to convert the XML selections to a table variable. The problem with the latter method is that SQL Server doesn’t allow the use of sp_xml_preparedocument inside a UDF, making it difficult to write a generic, reusable method.

Once again, the new XML features in SQL 2005 make this task easier, faster, and less resource intensive. If you create an XML string [or an .NET Dataset/object that can serialize as XML] with a column called PKValue that stores user-selections, you can write a UDF like the one in Listing B, to convert the XML string to a table variable, using the node method previously covered in this article. Listing B contains both a UDF as well as a sample to utilize it.

Listing B – UDF XML2TableVar
Converts an XML string with a node of PKValue to a table variable

CREATEFUNCTION [dbo].[XML2TableVar]

( @XMLString XML)

RETURNS

@tPKList TABLE ( PKValue int)

BEGIN

INSERTINTO @tPKList

SELECT Tbl.Col.value('.','int')

FROM @XMLString.nodes('//PKValue') Tbl( Col )

RETURN

END

-- Example Usage

-- Create an XML string to use in a subsequent join against a customer table

DECLARE @XMLString XML

SET @XMLString ='

-- Show the contents

SELECT *FROM [dbo].[XML2TableVar] (@XMLString) CustList

-- Perform a JOIN using the UDF

SELECT Customers.*FROM Customers

JOIN [dbo].[XML2TableVar] (@XMLString) CustList

ON Customers.CustomerPK = CustList.PKValue

3 - New SELECT FOR….XML capabilities

Listing C shows examples of querying to XML format, including the ability to specify an attribute-centric or element-centric format.

Listing C
(SELECT…FOR XML capabilities)

-- attribute-centric schema

SELECT*FROM orders WHERE OrderID = 10447

FORXMLAUTO,XMLSCHEMA

-- element-centric schema

SELECT*FROM orders WHERE OrderID = 10447

FORXMLAUTO, ELEMENTS ,XMLSCHEMA

4 - Performing partial text searches inside an XML DataColumn

Last, but certainly not least – some database store information in an XML format. For example, some will store address information inside an XML column. It can become a bit of a challenge to query that data, especially if end users want the ability to perform partial text searches.

Once again, we can use the exist method and clauses within the exist method to perform these types of queries. Listing D creates a simple address XML column, populates some sample data, and then performs a partial text query as follows:

WHERE Address.exist('/Address/AddressRecord [contains(@City,"burg")]')= 1

Listing D
(Performing partial text searches)

DECLARE @tTestAddress TABLE(Address XML)

INSERTINTO @tTestAddress VALUES('

CustomerID = "1"

Street=" 1945 14th Ave " City=" Atlantic City " State="NJ" Zip="91912" />

insertinto @tTestAddress values('

CustomerID = "2"

Street=" 27 Main Street " City=" Harrisburg " State="PA" Zip="44555"/>

SELECT*FROM @tTestAddress WHERE

Address.exist('/Address/AddressRecord [contains(@City,"burg")]')= 1

Recommended Reading :

For every piece of information that an article covers, there are always multiple items that aren’t covered. That’s a testament to how much XML functionality exists in SQL 2005. There are new capabilities for OPENROWSET, a modify method in the XML data type to manipulate XML data, and so much more. The objective of this article was to provide a starting point with some examples of the new XML. Here are some additional resources that provide additional information.

Shawn Wildermuth, Making Sense of the XML DataType in SQL Server 2005, May/June 2006 issue of CoDe Magazine.
Bob Beauchemin and Dan Sullivan, A Developer's Guide to SQL Server 2005 (Microsoft .NET Development Series) – there are multiple chapters on XML

Remember…GOOGLE is your friend. Sometimes just taking thirty minutes to Google some XML keywords will lead to more valuable information than you ever thought possible.

Writing CLR Stored Procedures in C#

2008-05-06T10:21:00.000+01:00

Writing CLR Stored Procedures in C#: "Writing CLR Stored Procedures in C#

As SQL Server 2005 rolls out DBA's are going to be forced to learn either C# or Visual Basic or both. Until now these were client side languages and not knowing them had little impact on your job. And if you write code in these languages your going to have to learn to use Visual Studio. This article covers the basics of C# and Visual Studio using a basic stored procedure as an example. It's written using the April CTP of SQL Server 2005.

This article shows you how http://www.sqlteam.com/item.asp?ItemID=21927"

Writing CLR Stored Procedures in C# - Introduction to C# (Part 1) - SQLTeam.com

2008-05-06T09:48:00.000+01:00

Writing CLR Stored Procedures in C# - Introduction to C# (Part 1) - SQLTeam.com

DotNetAddicted

SharePoint 2010 Questions And Answers

C# .Net Interview Questions

C# Interview Questions & Answers

The art of staying in the present | Specials | Cricinfo Magazine | Cricinfo.com

Insert datatable into SQL Server using Bulk Copy

PropertyGrid

Six C# features Java developers will kill for...

Using GetHashCode and Equals

Bulk Binding: FORALL

CodeProject: Database. Free source code and programming help

SQL Server 2005 | New XML Capabilities

Take Five with SQL Server 2005

Take Five with SQL Server 2005

New XML Capabilities in SQL Server 2005 Kevin S. Goff, Microsoft MVP 2007

1- XML Datatype and associated methods:

2 - A reusable T-SQL UDF to convert XML to a table variable

3 - New SELECT FOR….XML capabilities

4 - Performing partial text searches inside an XML DataColumn

Writing CLR Stored Procedures in C#

Writing CLR Stored Procedures in C# - Introduction to C# (Part 1) - SQLTeam.com

New XML Capabilities in SQL Server 2005
Kevin S. Goff, Microsoft MVP 2007