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October 26 2010 3 26 /10 /October /2010 16:27

6 ways of doing locking in .NET (Pessimistic and optimistic)
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Introduction

Why do we need locking?

How can we solve concurrency problems?

What kind of confusion is caused because of concurrency?

So how can we solve the above problems?

What is Optimistic locking?

How does optimistic lock work?

What are the different solutions by which we can implement optimistic locking?

Solution number 1:- Datasets

Solution number 2:- Use timestamp data type

Solution number 3:- Check old values and new values

But it looks like by using optimistic locking concurrency problems are not really solved?

What is pessimistic locking?

How can we do pessimistic locking?

What kind of locks can be acquired by using pessimistic locking?

The update lock is confusing can you explain in detail?

So what are the different types of isolation levels and when should be used when?

How can we specify Isolation?

Which transaction isolation level solves which problems from Concurrency?

Solution 4:- Can we see how dirty reads are solved using Read Committed?

So is Read uncommitted opposite of Read Committed?

Solution 5:- Can we see how lost update and non-repeatable read are solved using repeatable read?

Solution 6:- How are Phantom row problems addressed using Serializable Isolation level?

In what scenarios should we use optimistic and pessimistic locking?

What is a dead lock and how does shared lock avoid the same?

What are Lock hints?

 

Introduction

This article talks about 6 ways of doing locking in .NET. It starts with concurrency problems and then discusses about 3 ways of doing optimistic locking. As optimistic locking does not solve the concurrency issues from roots, it introduces pessimistic locking. It then moves ahead to explain how isolation levels can help us implement pessimistic locking. Each isolation level is explained with sample demonstration to make concepts clearer.
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Why do we need locking?

In multi-user environment it’s possible that multiple users can update the same record at the same time causing confusion between users. This issue is termed as concurrency.

How can we solve concurrency problems?

Concurrency problems can be solved by implementing proper “Locking strategy”. Locks prevent action on a resource to be performed when some other resource is already performing some action on it.

What kind of confusion is caused because of concurrency?

There are 4 kinds of major problems caused because of concurrency, below table shows the details of the same.

Problems Short description Explanation
Dirty reads "Dirty Read" occurs when one transaction is reading a record, which is part of a half, finished work of other transaction. • User A and user B are seeing value as “5”.
• User B changes the value “5” to “2”.
• User A is still seeing the value as “5”….Dirty read has happened.
Unrepeatable read In every data read if you get different values then it’s an “Unrepeatable Read” problem. • User A is seeing value as “5”.
• User B changes the value”5” to “2”.
• User A refreshes see values “5”, he is surprised….unrepeatable read has happened.
Phantom rows If “UPDATE” and “DELETE” SQL statements does not affect the data then it can be “Phantom Rows” problem. • User A updates all value “5’ to “2”.
• User B inserts a new record with value “2”.
• User A selects all record with value “2’ if all the values have changed, he is surprised to still find value “2” records…..Phantom rows have been inserted.
Lost updates "Lost Updates" are scenario where one updates which is successfully written to database is overwritten with other updates of other transaction. • User A updates all value form “5” to “2”.
• User B comes and updates all “2” values to “5”.
• User A has lost all his updates.

So how can we solve the above problems?

By using optimistic or pessimistic locking, the further coming article discusses the same.

What is Optimistic locking?

As the name suggests “optimistic” it assumes that multiple transaction will work without affecting each other. In other words no locks are enforced while doing optimistic locking. The transaction just veriafies that no other transaction has modified the data. In case of modification the transaction is rolled back.

How does optimistic lock work?

You can implement optimistic locking by numerous ways but the fundamental to implement optimistic locking remains same. It’s a 5 step process as shown below:-

• Record the current timestamp.

• Start changing the values.

• Before updating check whether anyone else has changed the values by checking the old time stamp and new time stamp.

• If it’s not equal rollbacks or else commit.

What are the different solutions by which we can implement optimistic locking?

There are 3 primary ways by which we can implement optimistic locking in .NET:-

Datasets: - Dataset by default implement optimistic locking. They do a check of old values and new values before updating.

Timestamp Data type: - Create a timestamp data type in your table and while updating check if old timestamp is equal to new timestamp.

Check old and new value: - Fetch the values, do the changes and while doing the final updates check if the old value and current values in database are equal. If they are not equal then rollback or else commits the values.

Solution number 1:- Datasets

As said in the previous section dataset handles optimistic concurrency by itself. Below is a simple snapshot where we held the debug point on Adapter’s update function and then changed the value from the SQL Server. When we ran the “update” function by removing the break point it threw “Concurrency” exception error as shown below.

If you run the profiler at the back end you can see it fires the update statement checking of the current values and the old values are same.

 exec sp_executesql N'UPDATE [tbl_items] SET [AuthorName] = @p1 WHERE (([Id] = @p2) AND ((@p3 = 1 AND [ItemName] IS NULL) OR ([ItemName] = @p4)) AND ((@p5 = 1 AND [Type] IS NULL) OR ([Type] = @p6)) AND ((@p7 = 1 AND [AuthorName] IS NULL) OR ([AuthorName] = @p8)) AND ((@p9 = 1 AND [Vendor] IS NULL) OR ([Vendor] = @p10)))',N'@p1 nvarchar(11),@p2 int,@p3 int,@p4 nvarchar(4),@p5 int,@p6 int,@p7 int,@p8 nvarchar(18),@p9 int,@p10 nvarchar(2)',@p1=N'this is new',@p2=2,@p3=0,@p4=N'1001',@p5=0,@p6=3,@p7=0,@p8=N'This is Old Author',@p9=0,@p10=N'kk' 

In this scenario we were trying to change the field value “AuthorName” to “This is new” but while updating it makes a check with the
 old value “This is old author”. Below is the downsized code snippet of the above SQL which shows the comparison with old value.

 ,@p8=N'This is Old Author' 

Solution number 2:- Use timestamp data type

The other way of doing optimistic locking is by using ‘TimeStamp’ data type of SQL Server. Time stamp automatically generates
a unique binary number every time you update the SQL Server data. Time stamp data types are for versioning your record updates.

To implement optimistic locking we first fetch the old ‘TimeStamp’ value and when we are trying to update we check if the old time
stamp is equal to the current time stamp as shown in the below code snippet.

 update tbl_items set itemname=@itemname where CurrentTimestamp=@OldTimeStamp 

We then check if any updates has happened, in case updates has not happened then we raise a serious error ‘16’ using SQL Server ‘raiserror’
as shown in the below code snippet.

 if(@@rowcount=0) begin raiserror('Hello some else changed the value',16,10) end 

If any concurrency violation takes place you should see the error propagated when you call ‘ExecuteNonQuery’ to the client side as
shown in the below figure.

Solution number 3:- Check old values and new values

Many times we would like to check concurrency on only certain fields and omit fields like identity etc. For those kind of scenarios
we can check the old value and the new value of the updated fields as shown in the below code snippet.

 update tbl_items set itemname=@itemname where itemname=@OldItemNameValue 

But it looks like by using optimistic locking concurrency problems are not really solved?

Yes, you said right. By using optimistic locking you only detect the concurrency problem. To solve concurrency issues from the roots
itself we need to use pessimistic locking. Optimistic is like prevention while pessimistic locking is actually the cure.

What is pessimistic locking?

 

Pessimistic locking assumes that concurrency / collision issues will happen so a lock is placed on the records and then data is updated.

How can we do pessimistic locking?

We can do pessimistic locking by specifying “IsolationLevel” in SQL Server stored procedures, ADO.NET level or by using transaction scope object.

What kind of locks can be acquired by using pessimistic locking?

There are 4 kinds of locks you can acquire Shared, Exclusive, Update and intent. The first two are actual locks while the other two
are hybrid locks and marker.

  When to use? Reads Allowed Writes Allowed
Shared lock When you want only to read and you do not want any other transactions to do update. Yes No
Exclusive When you want to modify data and you do not want anyone to read the transaction, neither you want anyone to update. No No
Update lock This is a hybrid lock. This lock is used when you want to do update operation which passes through multiple phases before the actual update happens. It first starts with shared lock in the read phase and then on the actual update it acquires an exclusive lock.    
  Read phase Yes No
  Manipulating phase Yes No
  Update phas No No
Intent Lock ( Demand locks) Intent lock is for lock hierarchy. This lock is used when you want to lock resources down in the hierarchy. For example a shared intent lock on a table means shared locks are placed on pages and rows with the table. NA NA
Schema locks When you are changing table structure. No No
Bulk update locks Used when you are doing bulk updates Table level No Table level No

 

The update lock is confusing can you explain in detail?

The other locks are pretty straight forward; the update lock is confusing because of its hybrid nature. Many times before we update we read the record. So during read the lock is shared and while actually updating we would like to have an exclusive lock. Update locks are more of transient locks.

 

So what are the different types of isolation levels and when should be used when?

There are 4 kinds of transaction isolation level, below is a simple table which shows when to use them and what locks they put.

Isolation Level Read Update Insert
Read Uncommitted Reads data which is yet not committed. Allowed Allowed
Read Committed ( Default) Reads data which is committed. Allowed Allowed
Repeatable Read Reads data which is committed. Not Allowed Allowed
Serializable Reads data which is committed. Not Allowed Not Allowed

How can we specify Isolation?

Isolation levels are features of RDBMS software, in other words they fundamental really belong to SQL Server and not to Ado.NET, EF or LINQ. Said and done that you can always set the transaction isolation level from any of these components.

Middle tier

In middle tier you can specify isolation level using transaction scope object.

 TransactionOptions TransOpt = New TransactionOptions(); TransOpt.IsolationLevel = System.Transactions.IsolationLevel.ReadCommitted; using(TransactionScope scope = new TransactionScope(TransactionScopeOption.Required, TransOptions)) { } 

ADO.NET

You can also specify transaction isolation level using “SqlTransaction” object in ADO.NET.

 SqlTransaction objtransaction = objConnection.BeginTransaction(System.Data.IsolationLevel.Serializable); 

SQL Server

You can also specify isolation level in TSQL using ‘SET TRANSACATION ISOLATION LEVEL’ as shown in the below code snippet.

 SET TRANSACTION ISOLATION LEVEL READ COMMITTED; 

Which transaction isolation level solves which problems from Concurrency?

Below is a chart which shows which transaction isolation level solves which problems of concurrency.

  Read committed(S) Repeatable read(I)    Serializable Read Uncommitted
Dirty reads

        Solves

        Solves     Solves             X
Lost updates             X         Solves     Solves             X
Non repeatable reads             X         Solves     Solves             X
Phantom rows             X               X     Solves             X

Solution 4:- Can we see how dirty reads are solved using Read Committed?

Some important Key points about read committed:-

• It’s the default transaction isolation level for SQL Server.

• Its reads only committed data. In other words any uncommitted data is not read and blocked until the commit happens. Below figure explains the same in more detail. You can see the update

If you want the see above things practically do the following:-

• Open 2 Query windows fire an update transaction but do not commit.

• In the second window try firing select query it will show a blocked query as shown in the below figure.

So is Read uncommitted opposite of Read Committed?

Yes, read uncommitted is opposite to read committed. When you set the transaction isolation level to read uncommitted, uncommitted data is also read.
Some important key points for read committed:-

• Uncommitted is see so dirty read possible.

• No locks held.

• Useful when locking is not important and more important is concurrency and throughput.

If you want to test the same, fire the below SQL statement which is doing an update and roll back. The roll back happens after 20 seconds halt. Within that time if you fire a select query you will get the uncommitted data and after 20 seconds you will see the old data this committed data is rolled back.

 set transaction isolation level read uncommitted Begin Tran Update customer set CustomerName='Changed' where CustomerCode='1001' WAITFOR DELAY '000:00:20' rollback tran 
 set transaction isolation level read uncommitted select * from Customer where CustomerCode='1001' 

Solution 5:- Can we see how lost update and non-repeatable read are solved using repeatable read?

By setting isolation level to repeatable read no one can read and update the data. Some key points about repeatable read isolation level are as follows:-

• Only committed data is read when repeatable transaction isolation level is set for select queries.

• When you select a record using repeatable read no one other transaction can update the record. , but selects are possible.

• If repeatable transaction is set in update query, until the transaction finishes no one can read or update the same.

• When select and update query is set to repeatable read other transaction can insert new records. In other words phantom rows are possible.

If you want to test this isolation level, fire the below syntax and try firing select and update queries they will be blocked and after 50 seconds you should see the data.

 set transaction isolation level repeatable read Begin Tran Update customer set CustomerName='Changed' where CustomerCode='1001' WAITFOR DELAY '000:00:50' rollback tran 

If you fire the below select query in repeatable read mode you will not be able to update for 50 seconds until the transaction finishes.

 set transaction isolation level repeatable read begin tran select * from Customer where CustomerCode='1001' WAITFOR DELAY '000:00:50' commit tran 

One important note you can add new records of customer code 1001, in other words phantom rows are possible.

Solution 6:- How are Phantom row problems addressed using Serializable Isolation level?

This is the highest level of isolation level; in this other transactions cannot update, select and insert records.
Some key points for serializable transaction are:-

• No other transaction can insert, update, delete or select when isolation level is serializable.

• Lot of blockings but all concurrency issues are solved.

 set transaction isolation level serializable begin tran select * from Customer where CustomerCode='1001' WAITFOR DELAY '000:00:50' commit tran 

In what scenarios should we use optimistic and pessimistic locking?

Working…

What is a dead lock and how does shared lock avoid the same?

Still working…

What are Lock hints?

Still working…

 

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How to sort interactively using SSRS? (SQL Server reporting services interview questions)

How to do conditional formatting in SSRS? (SQL Server reporting services interview questions with answers)

WHAT IS NORMALIZATION AND EXPLAIN 1NF 2NF AND 3NF IN SIMPLE WORDS? SQL SERVER INTERVIEW QUESTIONS WITH ANSWERS

What is the difference between Stored Procedures and Function (SQL Server interview question with answers)?

 

When you will use inner join and when you will use outer join? SQL Server interview questions with answers

 

Do you know anything about Temporary procedures in SQL?( SQL Server interview questions with answers)

 

4 SQL Server interview questions with answers on TempTb

 

Are full outer join and Cross join are same? ( SQL Server interview questions with answers)

 

Delete duplicate records: - SQL Server interview questions with answers

 

4 most asked  SQL queries during SQL Serverinterview’s

 

How Temporary tables are different from normal tables and what are its types ?( SQL Server interview questions with answers)

 

SQL Server interview Questions on JOIN’s

 

SQL Server interview questions: - How can you increase SQL performance?

 

SQL Server interview questions: - What problem you face if locking is not implemented?

 

Can we insert NULL’s in to UNIQUE key ? ( SQL Server  interview questions with answers)

 

Explain Normalization?(SQL Server Interview questions with answers)

Temp variablesVS Temp tables(SQL Server interview questions)

 


 




.NET INTERVIEW QUESTIONS & ANSWERS ARTICLE

 

.NET interview questions and answers: - How to reverse a string in .NET ( DotNet)?

.NET interview questions and answers: - What is the use of Click Once?

.NET interview questions and answers: - Will the below codes create new instances?

C# and .NET interview questions with answers – What is Nuget?

Dependency injection (DI) VS Inversion of Control (IOC)

.NET interview questions with answers: - What is the difference between Reflection and Dynamic?

Five Great .NET Framework 4.5 Features

ASP.NET MVC 4 interview questions with answers: - What is the use of “AllowHTML” and “ValidateInput” attributes?

.NET interview questions 6th edition (Sixth edition) - By Shivprasad Koirala

.NET interview questions with answers: – Can we use events without delegates ?

.Net Interview question Edition 6 is available now.

.NET interview questions with answers: – What’s the difference between catch with parameter and catch without parameter?

.NET interview questions : - What is the use and difference between “IS” and “AS” keyword?

.NET interview questions with answers: - Build solution VS Rebuild solution VS Clean solution

HTML 5 interview questions with answers for LocalStorage and SessionStorage

.NET 4.0 interview questions with answers: – What are code contracts?

What are portable class libraries? ( .NET interview questions with answers)

How to loop through ENUM using C# (.NET interview questions with answers)?

What are transactions in C#? (.NET interview questions with answers)

What are ACID Properties( .NET Interview questions with answers)?

.NET interview questions: – What are the areas that need to be concentrated for senior(9+ years experience)persons in .NET technologies?

.NET interview questions: - Explain real time scenarios in Factory Pattern, Abstract Pattern, Singleton, WCF and REST services

What is the difference between IS A and Can a Relationship?( .NET Interview questions with answers)

What is the use of ENUM Flags(.NET Enum Interview question 2)?

What is the difference between .Net,C#, Asp.net, Asp.net Web Forms and Asp.net MVC and MVC?( C# and ASP.NET Interview questions)

ADO.NET interview questions: - Explain in detail the fundamental of connection pooling?

.NET interview questions: – Can you explain generics in .NET?

What are Properties and methods ? ( .NET OOP Interview questions with answers)

What’s the first step you take for implementing any of Design Pattern?( .NET  Design pattern interview questions with answers)

.NET interview questions: - What are different types of JIT?

ADO.NET Interview Question: - What are the major differences between classic ADO and ADO.NET?

.NET interview questions: – What is the difference between Reflection and Dynamic?

What is the Use of interfaces?( .NET Interview questions with answers)

.NET interview questions: - What role did you play in your project and company?

Visual studio 2012 Fakes

.NET interview questions: - So how can we clean unmanaged objects and also maintain performance?

ADO.NET Interview Questions: - What are basic methods of Data adapter?

.NET interview questions: - What are system level exceptions and application level exceptions?

.NET interview questions: - What is UML and which are the important diagrams?

.NET interview questions: - What is time out support in regex (regular expression)?

.NET interview questions: - How can we improve performance of .NET?

.NET interview questions: - Can you explain the concept of “Short Circuiting”?

.NET interview questions: - Can you explain Forms authentication in detail?

What is the difference between VAR and Dynamic keyword? ( .NET Interview questions with answers)

.NET interview questions: - What are similarities and difference between Class and structure?

Can you compare String.IsNullOrEmpty vs String.IsNullOrWhiteSpace ? ( .Net Interview questions with answers)

.NET interview questions: - Distinguish between Reflection and Dynamic?

.NET interview questions: - In which scenarios we can use serialization and when to use what binary serialization or XML serialization?

.NET interview questions: - Are there any readymade objects in .NET by which we can implement Lazy loading?

.NET interview questions: - What are different access modifiers?

ADO.NET interview questions: - Explain in detail the fundamental of connection pooling how to enable and disable connection pooling?

ADO.NET interview questions: - What is the namespace in which .NET has the data functionality class?

ADO.NET interview questions: - What are the different components in ADO.NET?

ADO.NET interview questions: - Show difference between “Optimistic” and “Pessimistic” locking and how many ways are there to implement optimistic locking in ADO.NET?

.NET interview questions: - Does code contract only do dynamic checks?

ADO.NET interview questions: - How can we fire a simple SQL Statement using ADO.NET?

.NET interview questions: - What basic steps are needed to display a simple report in crystal?

ADO.NET interview questions: - What are basic methods of Data adapter and mention the use of data adapter?

.NET interview questions: - What is UML? How many types of diagrams are there in UML?

.Net Interview Questions - What is MVC, MVP and MVVM pattern?

.NET interview questions: - How can you define a property read only for external world and writable in the same assembly?

Explain the implicit and explicit conversion of data types with examples?( .NET interview questions on data type)

.NET interview questions: - What is Reflection its implementation and practical uses?

What is downcasting and upcasting? (.NET interview questions with answers)

.NET interview questions: - How to decide on the design consideration to take a Data grid, data list or repeater?

.NET interview questions: - If we want to update interface with new methods, what is the best practice?

.NET interview questions: - How does selection sort algorithm works?

XML(.NET) interview questions: - What is XML?

.NET Interview questions: - If a validation is very complex what will you do?

.NET interview questions: - How can we stop the class from further inheriting?

XML (.NET) Interview questions :- Explain simple Walk through of XmlReader.

.NET interview questions : - How can we improve performance of .NET and show the difference between .NET 1.X, 2.0, 3.0, 3.5 and 4.0?

How to convert string to ENUM value ?( .NET interview questions with answers)

.NET architecture interview questions series: - What is mean by modeling language?

.NET architecture interview questions : - What are benefits and Limitation of using Viewstate, hidden frames and Cookies?

.NET interview questions: - What is GAC (Global Assembly Cache)?

.NET interview questions: - Explain Nuget?

.NET Testing interview questions: - What is the difference between Unit testing, Assembly testing and Regression testing?


.NET interview questions: - What is Code Access Security (CAS) and how does it work? Is CAS supported in .NET 4.0?


.NET interview questions: - What are the advantages /disadvantages of lazy loading?


.NET interview questions: - What is the use of DEBUG directive?


.NET testing interview questions: - What is Mock testing and how to implement it?


.NET interview questions: - What is the difference between DEBUG and Release?


.NET testing interview questions: - How can we UNIT test private methods using VSTS? Is it good to practice to UNIT test Private methods?


Explain 3 layer architecture ( .NET Interview questions)?


.NET interview questions : - What is a delegate and how can we create a delegate? What is a multicast delegate?


ADO.NET interview questions: - How to add/remove row is in “Data Table” object of “Dataset”? How to load multiple tables in a Dataset & adding relation between tables in a Dataset?


What is the difference between Array, ArrayList and List?( .Net Interview questions)

.NET interview questions: - How to implement DTC in .NET?
.NET interview questions: - What is an Interface and what are abstract classes

.NET interview questions: - Interface vs. abstract class

.NET interview questions: - How to implement practically Lazy loading in .NET?


.NET interview questions: - How can we handle exceptions in .NET? What if we do not catch the exception?

.NET interview questions based on Projects.


.NET interview questions: - What is shadowing? What is the difference between Shadowing and Overriding?

.NET interview questions: - All about Design Patterns in .NET


.NET interview questions: - How can we improve performance of .NET/ASP.NET/SQL Server?

.NET interview questions: - What benefits does sealed keyword provide?


.NET Architecture UML interview question


.NET interview questions: - How to maintain performance and can clean unmanaged objects?


.NET interview questions: - Explain ENUM and its benefits? What is the use of Flagsin ENUM?

.NET interview questions: - How to create a windows service using .NET?

.NET interview questions: - Explain in details about Indexer and can we have static indexer in C#?

.NET interview questions: - What is the difference between arraylist and list? Are Arraylist faster or Arrays?

.NET interview questions: - What is Native Image Generator (Ngen.exe)? Does NGEN.EXE always improve performance?

.NET OOPS interview questions: - What is OOP? What are different properties provided by Object-oriented systems?

.NET OOPS interview questions: - How abstract with only abstract method is it different from interfaces? Also mention best practice to update interface with new methods?

.NET interview questions: - What is the difference between delegate and events? Can we have return type, access modifiers and shared events?

.NET interview questions: - What is Manifest? Where is the version information stored of an assembly? Is versioning applicable to private assemblies?

.NET Generics interview questions: - Explain Generics and concept of Generic Collection in .NET?

How to learn .NET: - In parent-child relationship which constructor will fire first and in which instances you will declare a constructor private?

Basics of .NET and learning tutorials on CTS and CLS


Online resource to learn .NET on Reflection and Dynamic

Online guide to learn .NET for Object initializer in C#?

QuestPond for Freshers on IL code, JIT, CLR, CTS, CLS and CAS

QuestPond: Interview Questions and Answers on AJAX and how does it help?



ASP.NET Interview Questions & Answers Article










MVC Interview Questions And Answers Article

 

(MODEL VIEW CONTROLLER)MVC INTERVIEW QUESTIONS AND ANSWERS

 

MVC INTERVIEW QUESTIONS WITH ANSWERS VIDEO: – WHAT IS WEB API HOW TO IMPLEMENT THE SAME?

 

ASP.NET MVC  4 INTERVIEW QUESTIONS WITH ANSWERS: - WHAT IS BUNDLING AND MINIFICATION IN MODEL VIEW CONTROLLER ?

 

MVC INTERVIEW QUESTIONS WITH ANSWERS :- IS IT POSSIBLE TO RETURN VALUES INSTEAD OF ACTIONRESULTS?

 

MVC INTERVIEW QUESTIONS WITH ANSWERS :- WHAT ARE THE ACTIONRESULTS AVAILABLE IN MVC?

 

MVC INTERVIEW QUESTIONS WITH ANSWERS:-HTML.PARTIALVSHTML.RENDERPARTIALVSHTML.RENDERPAGE IN MVC

MVC VS ASP.NET ( MVC INTERVIEW QUESTION WITH ANSWERS )?

 

HOW CAN WE DETECT THAT A MVC CONTROLLER IS CALLED BY POST OR GET ? ( ASP.NET MVC INTERVIEW QUESTIONS WITH ANSWERS)

 

WHAT ARE THE DIFFERENT WAYS BY WHICH YOU WILL GET FORM DATA IN CONTROLLER? ( MVC INTERVIEW QUESTIONS WITH ANSWERS)

 

WHAT IS THE DIFFERENCE BETWEEN PRESENTER AND CONTROLLER IN MVC?(MVC INTERVIEW QUESTIONS WITH ANSWERS)

 

LEARN MVC (MODEL VIEW CONTROLLER) STEP BY STEP IN 7 DAYS – DAY 4

 

MVC Interview questions and answers PDF

 

MVC interview questions with answers

 

ActionResult vs. View() vs. ViewResult :- MVC interview questions with answers

Explain Areas in MVC?( MVC interview questions with answers)

 

Can you explain the purpose of ViewModel in MVC?( ASP.NET MVC Interview questions with answers)

ASP.NET MVC interview questions: - What are Filters in MVC?

What are areas in MVC?( MVC Interview questions with answers)

Explain the concept of View Model in MVC? 

Exception Handling in MVC

Explain MVC application life cycle?

100 MVC Interview question PDF download released , Enjoy

How can we use two (multiple) models with a single view?(MVC Interview questions)

MVC HTML.Form vs Ajax.Form – MVC interview questions with answers

Learn Microsoft Business intelligence step by step – Day 1

Can you create TempBag just like ViewBag?( MVC Interview questions)

MVC Unit Testing Unleashed

MVC and .NET learning tutorials for components of MVC and how do you perform unit testing in MVC?

Explain MVC model binders ? ( ASP.NET MVC interview questions)

Explain the difference between layout and master pages ? (MVC Razor interview questions) 


ENTITY FRAMEWORK INTERVIEW QUESTIONS ARTICLE


Windows Workflow Foundation(WWF) interview questions with answers Article

XML Interview Questions With Answers Article


Explain XML,DTD and XSL?(XML interview questions with answers)

HTML 5 Interview questions With Answers Article

HTML 5 interview questions with answers for LocalStorage and SessionStorage

 

How is the page structure of HTML 5 different from HTML 4?( HTML 5 Interview questions with answers)

 

What is datalist in HTML 5 ( ASP.NET HTML interview questions)?

 

What are the different new form element types in HTML 5?( ASP.NET HTML 5 interview questions with answers)

 

What is output element in HTML 5?( ASP.NET HTML 5 interview questions)

 

What is the difference between Canvas and SVG graphics?(ASP.NET HTML 5 interview questions with answers)

 

ASP.NET HTML 5 interview questions on SVG and Canvas

ASP.NET HTML5 interview questions with answers

What are web workers and why do we need them ?( ASP.NET HTML interview questions with answers)

 

Why do we need HTML 5 server-sent events? (ASP.NET HTML interview questions)

How can we add and remove data from local storage?(ASP.NET HTML 5 interview questions)

What is local storage concept in HTML 5? ( ASP.NET HTML 5 interview questions)

What is the difference between local storage and cookies? ( ASP.NET HTML 5 interview questions)

What is WebSQL?( ASP.Net HTML 5 interview questions)

 

What is session storage and how can you create one?( ASP.Net HTML 5 interview questions with answers)

 

What is application cache in HTML5?( ASP.NET HTML 5 interview questions with answers)

ASP.NET HTML 5 Application cache interview questions with answers

 

Explain the term cascading in style sheet ? ( CSS Interview questions)

What is difference between DIV vs SPAN in HTML ?( ASP.Net Interview questions)

HTML 5 Canvas Interview questions: - Canvas in HTML 5.

QuestPond’s interview questions and answers on HTML 5

 

Learn HTML 5 in 3 days – Day 1

 

 

 

Dotnetspider Questions And Answers Article

 

 

What is downcasting and upcasting ? ( .NET interview questions with videos)

 

What is the difference between String vs string? ( C# interview questions) ?

 

 

JAVASCRIPT INTERVIEW QUESTIONS WITH ANSWERS ARTICLE

 


3 IMPORTANT JAVASCRIPT IMPORTANT INTERVIEW QUESTION WITH ANSWERS