. Is it possible to have Virtual Constructor? If yes, how? If not, Why not possible ?
There is nothing like Virtual Constructor. The Constructor cant be virtual as the constructor is a code which is responsible for creating a instance of a class and it cant be delegated to any other object by virtual keyword means.
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2. What about Virtual Destructor?
Yes there is a Virtual Destructor. A destructor can be virtual as it is possible as at runtime depending on the type of object baller is balling to , proper destructor will be called.
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3. What is Pure Virtual Function? Why and when it is used ?
The abstract class whose pure virtual method has to be implemented by all the classes which derive on these. Otherwise it would result in a compilation error.
This construct should be used when one wants to ensure that all the derived classes implement the method defined as pure virtual in base class.
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4. What is problem with Runtime type identification?
The run time type identification comes at a cost of performance penalty. Compiler maintains the class.
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5. How Virtual functions call up is maintained?
Through Look up tables added by the compile to every class image. This also leads to performance penalty.
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6. Can inline functions have a recursion?
No.
Syntax wise It is allowed. But then the function is no longer Inline. As the compiler will never know how deep the recursion is at compilation time.
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7. How do you link a C++ program to C functions?
By using the extern "C" linkage specification around the C function declarations.
Programmers should know about mangled function names and type-safe linkages. Then they should explain how the extern "C" linkage specification statement turns that feature off during compilation so that the linker properly links function calls to C functions.
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8. Explain the scope resolution operator?
It permits a program to reference an identifier in the global scope that has been hidden by another identifier with the same name in the local scope.
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9. How many ways are there to initialize an int with a constant?
1. int foo = 123;
2. int bar(123);
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10. What is your reaction to this line of code? delete this;
It is not a good programming Practice.
A good programmer will insist that you should absolutely never use the statement if the class is to be used by other programmers and instantiated as static, extern, or automatic objects. That much should be obvious.
The code has two built-in pitfalls. First, if it executes in a member function for an extern, static, or automatic object, the program will probably crash as soon as the delete statement executes. There is no portable way for an object to tell that it was instantiated on the heap, so the class cannot assert that its object is properly instantiated. Second, when an object commits suicide this way, the using program might not know about its demise. As far as the instantiating program is concerned, the object remains in scope and continues to exist even though the object did itself in. Subsequent dereferencing of the baller can and usually does lead to disaster. I think that the language rules should disallow the idiom, but that's another matter.
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11. What is the difference between a copy constructor and an overloaded assignment operator?
A copy constructor constructs a new object by using the content of the argument object. An overloaded assignment operator assigns the contents of an existing object to another existing object of the same class.
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12. When should you use multiple inheritance?
There are three acceptable answers:- "Never," "Rarely," and "When the problem domain cannot be accurately modeled any other way."
Consider an Asset class, Building class, Vehicle class, and CompanyCar class. All company cars are vehicles. Some company cars are assets because the organizations own them. Others might be leased. Not all assets are vehicles. Money accounts are assets. Real estate holdings are assets. Some real estate holdings are buildings. Not all buildings are assets. Ad infinitum. When you diagram these relationships, it becomes apparent that multiple inheritance is a likely and intuitive way to model this common problem domain. The applicant should understand, however, that multiple inheritance, like a chainsaw, is a useful tool that has its perils, needs respect, and is best avoided except when nothing else will do.
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13. What is a virtual destructor?
The simple answer is that a virtual destructor is one that is declared with the virtual attribute.
The behavior of a virtual destructor is what is important. If you destroy an object through a baller or reference to a base class, and the base-class destructor is not virtual, the derived-class destructors are not executed, and the destruction might not be comple
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14. Can a constructor throw a exception? How to handle the error when the constructor fails?
The constructor never throws a error.
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15. What are the debugging methods you use when came across a problem?
Debugging with tools like :
GDB, DBG, Forte, Visual Studio.
Analyzing the Core dump.
Using tusc to trace the last system call before crash.
Putting Debug statements in the program source code.
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16. How the compilers arranges the various sections in the executable image?
The executable had following sections:-
Data Section (uninitialized data variable section, initialized data variable section )
Code Section
Remember that all static variables are allocated in the initialized variable section.
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17. Explain the ISA and HASA class relationships. How would you implement each in a class design?
A specialized class "is" a specialization of another class and, therefore, has the ISA relationship with the other class.
This relationship is best implemented by embedding an object of the Salary class in the Employee class.
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18. When is a template a better solution than a base class?
When you are designing a generic class to contain or otherwise manage objects of other types, when the format and behavior of those other types are unimportant to their containment or management, and particularly when those other types are unknown (thus, the generality) to the designer of the container or manager class.
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19. What are the differences between a C++ struct and C++ class?
The default member and base-class access specifies are different.
This is one of the commonly misunderstood aspects of C++. Believe it or not, many programmers think that a C++ struct is just like a C struct, while a C++ class has inheritance, access specifies, member functions, overloaded operators, and so on. Actually, the C++ struct has all the features of the class. The only differences are that a struct defaults to public member access and public base-class inheritance, and a class defaults to the private access specified and private base-class inheritance.
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20. How do you know that your class needs a virtual destructor?
If your class has at least one virtual function, you should make a destructor for this class virtual. This will allow you to delete a dynamic object through a baller to a base class object. If the destructor is non-virtual, then wrong destructor will be invoked during deletion of the dynamic object.
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21. What is the difference between new/delete and malloc/free?
Malloc/free do not know about constructors and destructors. New and delete create and destroy objects, while malloc and free allocate and deallocate memory.
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22. What happens when a function throws an exception that was not specified by an exception specification for this function?
Unexpected() is called, which, by default, will eventually trigger abort().
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23. Can you think of a situation where your program would crash without reaching the breakball, which you set at the beginning of main()?
C++ allows for dynamic initialization of global variables before main() is invoked. It is possible that initialization of global will invoke some function. If this function crashes the crash will occur before main() is entered.
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24. What issue do auto_ptr objects address?
If you use auto_ptr objects you would not have to be concerned with heap objects not being deleted even if the exception is thrown.
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25. Is there any problem with the following:
char *a=NULL; char& p = *a;?
The result is undefined. You should never do this. A reference must always refer to some object.
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26. Why do C++ compilers need name mangling?
Name mangling is the rule according to which C++ changes function's name into function signature before passing that function to a linker. This is how the linker differentiates between different functions with the same name.
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27. Is there anything you can do in C++ that you cannot do in C?
No. There is nothing you can do in C++ that you cannot do in C. After all you can write a C++ compiler in C
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1.What are the OOPS concepts?
1) Encapsulation: It is the mechanism that binds together code and data in manipulates, and keeps both safe from outside interference and misuse. In short it isolates a particular code and data from all other codes and data. A well-defined interface controls the access to that particular code and data.
2) Inheritance: It is the process by which one object acquires the properties of another object. This supports the hierarchical classification. Without the use of hierarchies, each object would need to define all its characteristics explicitly. However, by use of inheritance, an object need only define those qualities that make it unique within its class. It can inherit its general attributes from its parent. A new sub-class inherits all of the attributes of all of its ancestors.
3) Polymorphism: It is a feature that allows one interface to be used for general class of actions. The specific action is determined by the exact nature of the situation. In general polymorphism means "one interface, multiple methods", This means that it is possible to design a generic interface to a group of related activities. This helps reduce complexity by allowing the same interface to be used to specify a general class of action. It is the compiler's job to select the specific action (that is, method) as it applies to each situation.
2.What is the difference between a Struct and a Class?
The struct type is suitable for representing lightweight objects such as Point, Rectangle, and Color. Although it is possible to represent a point as a class, a struct is more efficient in some scenarios. For example, if you declare an array of 1000 Point objects, you will allocate additional memory for referencing each object. In this case, the struct is less expensive.
When you create a struct object using the new operator, it gets created and the appropriate constructor is called. Unlike classes, structs can be instantiated without using the new operator. If you do not use new, the fields will remain unassigned and the object cannot be used until all of the fields are initialized.
It is an error to declare a default (parameterless) constructor for a struct. A default constructor is always provided to initialize the struct members to their default values.
It is an error to initialize an instance field in a struct.
There is no inheritance for structs as there is for classes. A struct cannot inherit from another struct or class, and it cannot be the base of a class. Structs, however, inherit from the base class Object. A struct can implement interfaces, and it does that exactly as classes do.
A struct is a value type, while a class is a reference type.
3.Value type & reference types difference? Example from .NET. Integer & struct are value types or reference types in .NET?
Most programming languages provide built-in data types, such as integers and floating-point numbers, that are copied when they are passed as arguments (that is, they are passed by value). In the .NET Framework, these are called value types. The runtime supports two kinds of value types:
Built-in value types
The .NET Framework defines built-in value types, such as System.Int32 and System.Boolean, which correspond and are identical to primitive data types used by programming languages.
User-defined value types
Your language will provide ways to define your own value types, which derive from System.ValueType. If you want to define a type representing a value that is small, such as a complex number (using two floating-point numbers), you might choose to define it as a value type because you can pass the value type efficiently by value. If the type you are defining would be more efficiently passed by reference, you should define it as a class instead.
Variables of reference types, referred to as objects, store references to the actual data. This following are the reference types:
class, interface, delegate,
This following are the built-in reference types:
object, string
4.What is Inheritance, Multiple Inheritance, Shared and Repeatable Inheritance?
**
5.What is Method overloading?
Method overloading occurs when a class contains two methods with the same name, but different signatures.
6.What is Method Overriding? How to override a function in C#?
Use the override modifier to modify a method, a property, an indexer, or an event. An override method provides a new implementation of a member inherited from a base class. The method overridden by an override declaration is known as the overridden base method. The overridden base method must have the same signature as the override method.You cannot override a non-virtual or static method. The overridden base method must be virtual, abstract, or override.
7.Can we call a base class method without creating instance?
Its possible If its a static method. Its possible by inheriting from that class also. Its possible from derived classes using base keyword.
8.You have one base class virtual function how will call that function from derived class?
Ans:class a
{public virtual int m()
{
return 1;}
}
class b:a
{public int j()
{return m();
}
}
9.In which cases you use override and new base?
Use the new modifier to explicitly hide a member inherited from a base class. To hide an inherited member, declare it in the derived class using the same name, and modify it with the new modifier.
C# Language features
10.What are Sealed Classes in C#?
The sealed modifier is used to prevent derivation from a class. A compile-time error occurs if a sealed class is specified as the base class of another class. (A sealed class cannot also be an abstract class)
11.What is Polymorphism? How does VB.NET/C# achieve polymorphism?
**
12.class Token
{public string Display()
{//Implementation goes here
return "base";
}
}
class IdentifierToken:Token
{public new string Display() //What is the use of new keyword
{//Implementation goes here
return "derive";
}
}
static void Method(Token t)
{Console.Write(t.Display()
);
}
public static void Main()
{IdentifierToken Variable=new IdentifierToken();
Method(Variable); //Which Class Method is called here
Console.ReadLine();
}
For the above code What is the "new" keyword and Which Class Method is called here
A: it will call base class Display method
13.class Token
{public virtual string Display()
{//Implementation goes here
return "base";
}
}
class IdentifierToken:Token
{public override string Display() //What is the use of new keyword
{//Implementation goes here
return "derive";
}
}
static void Method(Token t)
{Console.Write(t.Display()
);
}
public static void Main()
{IdentifierToken Variable=new IdentifierToken();
Method(Variable); //Which Class Method is called here
Console.ReadLine();
}
A: Derive
SQL
1. How do you implement one-to-one, one-to-many and many-to-many relationships while designing tables?
One-to-One relationship can be implemented as a single table and rarely as two tables with primary and foreign key relationships.
One-to-Many relationships are implemented by splitting the data into two tables with primary key and foreign key relationships.
Many-to-Many relationships are implemented using a junction table with the keys from both the tables forming the composite primary key of the junction table. It will be a good idea to read up a database designing fundamentals text book.
2. What's the difference between a primary key and a unique key?
Both primary key and unique enforce uniqueness of the column on which they are defined. But by default primary key creates a clustered index on the column, where are unique creates a nonclustered index by default. Another major difference is that, primary key doesn't allow NULLs, but nique key allows one NULL only.
3. What are user defined datatypes and when you should go for them?
User defined datatypes let you extend the base SQL Server datatypes by providing a descriptive name, and format to the database. Take for example, in your database, there is a column called Flight_Num which appears in many tables. In all these tables it should be varchar(8). In this case you could create a user defined datatype called Flight_num_type of varchar(8) and use it across all your tables.
4. What is bit datatype and what's the information that can be stored inside a bit column?
Bit datatype is used to store boolean information like 1 or 0 (true or false). Untill SQL Server 6.5 bit datatype could hold either a 1 or 0 and there was no support for NULL. But from SQL Server 7.0 onwards, bit datatype can represent a third state, which is NULL.
5. Define candidate key, alternate key, composite key
A candidate key is one that can identify each row of a table uniquely. Generally a candidate key becomes the primary key of the table. If the table has more than one candidate key, one of them will become the primary key, and the rest are called alternate keys.
A key formed by combining at least two or more columns is called composite key.
6. What are defaults? Is there a column to which a default can't be bound?
A default is a value that will be used by a column, if no value is supplied to that column while inserting data. IDENTITY columns and timestamp columns can't have defaults bound to them. See CREATE DEFUALT in books online.
7. What is a transaction and what are ACID properties?
A transaction is a logical unit of work in which, all the steps must be performed or none. ACID stands for Atomicity, Consistency, Isolation, Durability. These are the properties of a transaction. For more information and explanation of these properties, see SQL Server books online or any RDBMS fundamentals text book.
8. Explain different isolation levels
An isolation level determines the degree of isolation of data between concurrent transactions. The default SQL Server isolation level is Read Committed. Here are the other isolation levels (in the ascending order of isolation): Read Uncommitted, Read Committed, Repeatable Read, Serializable. See SQL Server books online for an explanation of the isolation levels. Be sure to read about SET TRANSACTION ISOLATION LEVEL, which lets you customize the isolation level at the connection level.
9. CREATE INDEX myIndex ON myTable(myColumn)
What type of Index will get created after executing the above statement?
Non-clustered index. Important thing to note: By default a clustered index gets created on the primary key, unless specified otherwise.
10. What's the maximum size of a row?
8060 bytes. Don't be surprised with questions like 'what is the maximum number of columns per table'. Check out SQL Server books online for the page titled: "Maximum Capacity Specifications".
11. Explain Active/Active and Active/Passive cluster configurations
Hopefully you have experience setting up cluster servers. But if you don't, at least be familiar with the way clustering works and the two clustering configurations Active/Active and Active/Passive. SQL Server books online has enough information on this topic and there is a good white paper available on Microsoft site.
12. Explain the architecture of SQL Server
This is a very important question and you better be able to answer it if consider yourself a DBA. SQL Server books online is the best place to read about SQL Server architecture. Read up the chapter dedicated to SQL Server Architecture.
13. What is lock escalation?
Lock escalation is the process of converting a lot of low level locks (like row locks, page locks) into higher level locks (like table locks). Every lock is a memory structure too many locks would mean, more memory being occupied by locks. To prevent this from happening, SQL Server escalates the many fine-grain locks to fewer coarse-grain locks. Lock escalation threshold was definable in SQL Server 6.5, but from SQL Server 7.0 onwards it's dynamically managed by SQL Server.
14. What's the difference between DELETE TABLE and TRUNCATE TABLE commands?
DELETE TABLE is a logged operation, so the deletion of each row gets logged in the transaction log, which makes it slow. TRUNCATE TABLE also deletes all the rows in a table, but it won't log the deletion of each row, instead it logs the deallocation of the data pages of the table, which makes it faster. Of course, TRUNCATE TABLE can be rolled back.
15. Explain the storage models of OLAP
Check out MOLAP, ROLAP and HOLAP in SQL Server books online for more infomation.
16. What are the new features introduced in SQL Server 2000 (or the latest release of SQL Server at the time of your interview)? What changed between the previous version of SQL Server and the current version?
This question is generally asked to see how current is your knowledge. Generally there is a section in the beginning of the books online titled "What's New", which has all such information. Of course, reading just that is not enough, you should have tried those things to better answer the questions. Also check out the section titled "Backward Compatibility" in books online which talks about the changes that have taken place in the new version.
1. What are constraints? Explain different types of constraints
Constraints enable the RDBMS enforce the integrity of the database automatically, without needing you to create triggers, rule or defaults.
Types of constraints: NOT NULL, CHECK, UNIQUE, PRIMARY KEY, FOREIGN KEY
For an explanation of these constraints see books online for the pages titled: "Constraints" and "CREATE TABLE", "ALTER TABLE"
2. What is an index? What are the types of indexes? How many clustered indexes can be created on a table? I create a separate index on each column of a table. what are the advantages and disadvantages of this approach?
Indexes in SQL Server are similar to the indexes in books. They help SQL Server retrieve the data quicker.Indexes are of two types. Clustered indexes and non-clustered indexes. When you craete a clustered index on a table, all the rows in the table are stored in the order of the clustered index key. So, there can be only one clustered index per table. Non-clustered indexes have their own storage separate from the table data storage. Non-clustered indexes are stored as B-tree structures (so do clustered indexes), with the leaf level nodes having the index key and it's row locater. The row located could be the RID or the Clustered index key, depending up on the absence or presence of clustered index on the table.If you create an index on each column of a table, it improves the query performance, as the query optimizer can choose from all the existing indexes to come up with an efficient execution plan. At the same t ime, data modification operations (such as INSERT, UPDATE, DELETE) will become slow, as every time data changes in the table, all the indexes need to be updated. Another disadvantage is that, indexes need disk space, the more indexes you have, more disk space is used.
3. What is RAID and what are different types of RAID configurations?
RAID stands for Redundant Array of Inexpensive Disks, used to provide fault tolerance to database servers. There are six RAID levels 0 through 5 offering different levels of performance, fault tolerance. MSDN has some information about RAID levels and for detailed information, check out the RAID advisory board's homepage.
4. What are the steps you will take to improve performance of a poor performing query?
This is a very open ended question and there could be a lot of reasons behind the poor performance of a query. But some general issues that you could talk about would be: No indexes, table scans, missing or out of date statistics, blocking, excess recompilations of stored procedures, procedures and triggers without SET NOCOUNT ON, poorly written query with unnecessarily complicated joins, too much normalization, excess usage of cursors and temporary tables. Some of the tools/ways that help you troubleshooting performance problems are: SET SHOWPLAN_ALL ON, SET SHOWPLAN_TEXT ON, SET STATISTICS IO ON, SQL Server Profiler, Windows NT /2000 Performance monitor, Graphical execution plan in Query Analyzer. Download the white paper on performance tuning SQL Server from Microsoft web site. Don't forget to check out sql-server-performance.com
5. What are the steps you will take, if you are tasked with securing an SQL Server?
Again this is another open ended question. Here are some things you could talk about: Preferring NT authentication, using server, database and application roles to control access to the data, securing the physical database files using NTFS permissions, using an unguessable SA password, restricting physical access to the SQL Server, renaming the Administrator account on the SQL Server computer, disabling the Guest account, enabling auditing, using multiprotocol encryption, setting up SSL, setting up firewalls, isolating SQL Server from the web server etc.
6. What is a deadlock and what is a live lock? How will you go about resolving deadlocks?
Deadlock is a situation when two processes, each having a lock on one piece of data, attempt to acquire a lock on the other's piece. Each process would wait indefinitely for the other to release the lock, unless one of the user processes is terminated. SQL Server detects deadlocks and terminates one user's process. A livelock is one, where a request for an exclusive lock is repeatedly denied because a series of overlapping shared locks keeps interfering. SQL Server detects the situation after four denials and refuses further shared locks. A livelock also occurs when read transactions monopolize a table or page, forcing a write transaction to wait indefinitely.
7. What is blocking and how would you troubleshoot it?
Blocking happens when one connection from an application holds a lock and a second connection requires a conflicting lock type. This forces the second connection to wait, blocked on the first. Read up the following topics in SQL Server books online: Understanding and avoiding blocking, Coding efficient transactions.
8. Explain CREATE DATABASE syntax
Many of us are used to craeting databases from the Enterprise Manager or by just issuing the command: CREATE DATABAE MyDB. But what if you have to create a database with two filegroups, one on drive C and the other on drive D with log on drive E with an initial size of 600 MB and with a growth factor of 15%? That's why being a DBA you should be familiar with the CREATE DATABASE syntax. Check out SQL Server books online for more information.
9. How to restart SQL Server in single user mode? How to start SQL Server in minimal configuration mode?
SQL Server can be started from command line, using the SQLSERVR.EXE. This EXE has some very important parameters with which a DBA should be familiar with. -m is used for starting SQL Server in single user mode and -f is used to start the SQL Server in minimal configuration mode. Check out SQL Server books online for more parameters and their explanations.
10. As a part of your job, what are the DBCC commands that you commonly use for database maintenance?
DBCC CHECKDB, DBCC CHECKTABLE, DBCC CHECKCATALOG, DBCC CHECKALLOC, DBCC SHOWCONTIG, DBCC SHRINKDATABASE, DBCC SHRINKFILE etc. But there are a whole load of DBCC commands which are very useful for DBAs. Check out SQL Server books online for more information.
11. What are statistics, under what circumstances they go out of date, how do you update them?
Statistics determine the selectivity of the indexes. If an indexed column has unique values then the selectivity of that index is more, as opposed to an index with non-unique values. Query optimizer uses these indexes in determining whether to choose an index or not while executing a query.
Some situations under which you should update statistics:
1) If there is significant change in the key values in the index 2) If a large amount of data in an indexed column has been added, changed, or removed (that is, if the distribution of key values has changed), or the table has been truncated using the TRUNCATE TABLE statement and then repopulated 3) Database is upgraded from a previous version Look up SQL Server books online for the following commands: UPDATE STATISTICS, STATS_DATE, DBCC SHOW_STATISTICS, CREATE STATISTICS, DROP STATISTICS, sp_autostats, sp_createstats, sp_updatestats
12. What are the different ways of moving data/databases between servers and databases in SQL Server?
There are lots of options available, you have to choose your option depending upon your requirements. Some of the options you have are: BACKUP/RESTORE, dettaching and attaching databases, replication, DTS, BCP, logshipping, INSERT...SELECT, SELECT...INTO, creating INSERT scripts to generate data.
13. Explain different types of BACKUPs available in SQL Server? Given a particular scenario, how would you go about choosing a backup plan?
Types of backups you can create in SQL Sever 7.0+ are Full database backup, differential database backup, transaction log backup, filegroup backup. Check out the BACKUP and RESTORE commands in SQL Server books online. Be prepared to write the commands in your interview. Books online also has information on detailed backup/restore architecture and when one should go for a particular kind of backup.
14. What is database replication? What are the different types of replication you can set up in SQL Server?
Replication is the process of copying/moving data between databases on the same or different servers. SQL Server supports the following types of replication scenarios:
o Snapshot replication
o Transactional replication (with immediate updating subscribers, with queued updating subscribers)
o Merge replication
See SQL Server books online for indepth coverage on replication. Be prepared to explain how different replication agents function, what are the main system tables used in replication etc.
15. How to determine the service pack currently installed on SQL Server?
The global variable @@Version stores the build number of the sqlservr.exe, which is used to determine the service pack installed. To know more about this process visit
What are cursors? Explain different types of cursors. What are the disadvantages of cursors? How can you avoid cursors?
Cursors allow row-by-row processing of the resultsets.Types of cursors: Static, Dynamic, Forward-only, Keyset-driven. See books online for more information.Disadvantages of cursors: Each time you fetch a row from the cursor, it results in a network roundtrip, where as a normal SELECT query makes only one rowundtrip, however large the resultset is. Cursors are also costly because they require more resources and temporary storage (results in more IO operations). Furthere, there are restrictions on the SELECT statements that can be used with some types of cursors. Most of the times, set based operations can be used instead of cursors. Here is an example:
If you have to give a flat hike to your employees using the following criteria:
Salary between 30000 and 40000 -- 5000 hike
Salary between 40000 and 55000 -- 7000 hike
Salary between 55000 and 65000 -- 9000 hike
In this situation many developers tend to use a cursor, determine each employee's salary and update his salary according to the above formula. But the same can be achieved by multiple update statements or can be combined in a single UPDATE statement as shown below:
UPDATE tbl_emp SET salary =
CASE WHEN salary BETWEEN 30000 AND 40000 THEN salary + 5000
WHEN salary BETWEEN 40000 AND 55000 THEN salary + 7000
WHEN salary BETWEEN 55000 AND 65000 THEN salary + 10000
END
Another situation in which developers tend to use cursors: You need to call a stored procedure when a column in a particular row meets certain condition. You don't have to use cursors for this. This can be achieved using WHILE loop, as long as there is a unique key to identify each row.
17. Write down the general syntax for a SELECT statements covering all the options
Here's the basic syntax: (Also checkout SELECT in books online for advanced syntax).
SELECT select_list
[INTO new_table_]
FROM table_source
[WHERE search_condition]
[GROUP BY group_by_expression]
[HAVING search_condition]
[ORDER BY order_expression [ASC | DESC] ]
18. What is a join and explain different types of joins
Joins are used in queries to explain how different tables are related. Joins also let you select data from a table depending upon data from another table.
Types of joins: INNER JOINs, OUTER JOINs, CROSS JOINs.OUTER JOINs are further classified as LEFT OUTER JOINS, RIGHT OUTER JOINS and FULL OUTER JOINS.
19. Can you have a nested transaction?
Yes, very much. Check out BEGIN TRAN, COMMIT, ROLLBACK, SAVE TRAN and @@TRANCOUNT
20. What is an extended stored procedure? Can you instantiate a COM object by using T-SQL?
An extended stored procedure is a function within a DLL (written in a programming language like C, C++ using Open Data Services (ODS) API) that can be called from T-SQL,just the way we call normal stored procedures using the EXEC statement. See books online to learn how to create extended stored procedures and how to add them to SQL Server.
Yes, you can instantiate a COM (written in languages like VB, VC++) object from T-SQL by using sp_OACreate stored procedure. Also see books online for sp_OAMethod, sp_OAGetProperty, sp_OASetProperty, sp_OADestroy.
21. What is the system function to get the current user's user id?
USER_ID().Also check out other system functions like USER_NAME(), SYSTEM_USER, SESSION_USER, CURRENT_USER, USER, SUSER_SID(), HOST_NAME().
22. What are triggers? How many triggers you can have on a table? How to invoke a trigger on demand?
Triggers are special kind of stored procedures that get executed automatically when an INSERT, UPDATE or DELETE operation takes place on a table. In SQL Server 6.5 you could define only 3 triggers per table, one for INSERT, one for UPDATE and one for DELETE. From SQL Server 7.0 onwards, this restriction is gone, and you could create multiple triggers per each action. But in 7.0 there's no way to control the order in which the triggers fire. In SQL Server 2000 you could specify which trigger fires first or fires last using sp_settriggerorder Triggers can't be invoked on demand. They get triggered only when an associated action (INSERT, UPDATE, DELETE) happens on the table on which they are defined. Triggers are generally used to implement business rules, auditing. Triggers can also be used to extend the referential integrity checks, but wherever possible, use constraints for this purpose, instead of triggers, as constraints are much faster. Till SQL Server 7.0, triggers fire only after the data modification operation happens. So in a way, they are called post triggers. But in SQL Server 2000 you could create pre triggers also. Search SQL Server 2000 books online for INSTEAD OF triggers.
23. There is a trigger defined for INSERT operations on a table, in an OLTP system. The trigger is written to instantiate a COM object and pass the newly insterted rows to it for some custom processing. What do you think of this implementation? Can this be implemented better?
Instantiating COM objects is a time consuming process and since you are doing it from within a trigger, it slows down the data insertion process. Same is the case with sending emails from triggers. This scenario can be better implemented by logging all the necessary data into a separate table, and have a job which periodically checks this table and does the needful.
24. What is a self join? Explain it with an example
Self join is just like any other join, except that two instances of the same table will be joined in the query. Here is an example: Employees table which contains rows for normal employees as well as managers. So, to find out the managers of all the employees, you need a self join.
CREATE TABLE emp
(empid int,
mgrid int,
empname char(10)
)
INSERT emp SELECT 1,2,'Vyas'
INSERT emp SELECT 2,3,'Mohan'
INSERT emp SELECT 3,NULL,'Shobha'
INSERT emp SELECT 4,2,'Shridhar'
INSERT emp SELECT 5,2,'Sourabh'
SELECT t1.empname [Employee], t2.empname [Manager]
FROM emp t1, emp t2
WHERE t1.mgrid = t2.empid
Here's an advanced query using a LEFT OUTER JOIN that even returns the employees without managers (super bosses)
SELECT t1.empname [Employee], COALESCE(t2.empname, 'No manager') [Manager]
FROM emp t1
LEFT OUTER JOIN
emp t2
ON
t1.mgrid = t2.empid
Whats the difference between System.String and System.Text.StringBuilder classes?
System.String is immutable. System.StringBuilder was designed with the purpose of having a mutable string where a variety of operations can be performed.
Whats the advantage of using System.Text.StringBuilder over System.String?
StringBuilder is more efficient in cases where there is a large amount of string manipulation. Strings are immutable, so each time a string is changed, a new instance in memory is created.
Can you store multiple data types in System.Array?
No.
Whats the difference between the System.Array.CopyTo() and System.Array.Clone()?
The Clone() method returns a new array (a shallow copy) object containing all the elements in the original array. The CopyTo() method copies the elements into another existing array. Both perform a shallow copy. A shallow copy means the contents (each array element) contains references to the same object as the elements in the original array. A deep copy (which neither of these methods performs) would create a new instance of each element's object, resulting in a different, yet identacle object.
How can you sort the elements of the array in descending order?
By calling Sort() and then Reverse() methods.
Whats the .NET collection class that allows an element to be accessed using a unique key?
HashTable.
What class is underneath the SortedList class?
A sorted HashTable.
Will the finally block get executed if an exception has not occurred?¬
Yes.
Whats the C# syntax to catch any possible exception?
A catch block that catches the exception of type System.Exception. You can also omit the parameter data type in this case and just write catch {}.
Can multiple catch blocks be executed for a single try statement?
No. Once the proper catch block processed, control is transferred to the finally block (if there are any).
Explain the three services model commonly know as a three-tier application.
Presentation (UI), Business (logic and underlying code) and Data (from storage or other sources).
Class Questions
What is the syntax to inherit from a class in C#?
Place a colon and then the name of the base class.
Example: class MyNewClass : MyBaseClass
Can you prevent your class from being inherited by another class?
Yes. The keyword sealed will prevent the class from being inherited.
Can you allow a class to be inherited, but prevent the method from being over-ridden?
Yes. Just leave the class public and make the method sealed.
Whats an abstract class?
A class that cannot be instantiated. An abstract class is a class that must be inherited and have the methods overridden. An abstract class is essentially a blueprint for a class without any implementation.
When do you absolutely have to declare a class as abstract?
1. When the class itself is inherited from an abstract class, but not all base abstract methods have been overridden.
2. When at least one of the methods in the class is abstract.
What is an interface class?
Interfaces, like classes, define a set of properties, methods, and events. But unlike classes, interfaces do not provide implementation. They are implemented by classes, and defined as separate entities from classes.
Why cant you specify the accessibility modifier for methods inside the interface?
They all must be public, and are therefore public by default.
Can you inherit multiple interfaces?
Yes. .NET does support multiple interfaces.
What happens if you inherit multiple interfaces and they have conflicting method names?
Its up to you to implement the method inside your own class, so implementation is left entirely up to you. This might cause a problem on a higher-level scale if similarly named methods from different interfaces expect different data, but as far as compiler cares youre okay.
To Do: Investigate
Whats the difference between an interface and abstract class?
In an interface class, all methods are abstract - there is no implementation. In an abstract class some methods can be concrete. In an interface class, no accessibility modifiers are allowed. An abstract class may have accessibility modifiers.
What is the difference between a Struct and a Class?
Structs are value-type variables and are thus saved on the stack, additional overhead but faster retrieval. Another difference is that structs cannot inherit.
Method and Property Questions
Whats the implicit name of the parameter that gets passed into the set method/property of a class?
Value. The data type of the value parameter is defined by whatever data type the property is declared as.
What does the keyword virtual declare for a method or property?
The method or property can be overridden.
How is method overriding different from method overloading?
When overriding a method, you change the behavior of the method for the derived class. Overloading a method simply involves having another method with the same name within the class.
Can you declare an override method to be static if the original method is not static?
No. The signature of the virtual method must remain the same. (Note: Only the keyword virtual is changed to keyword override)
What are the different ways a method can be overloaded?
Different parameter data types, different number of parameters, different order of parameters.
If a base class has a number of overloaded constructors, and an inheriting class has a number of overloaded constructors; can you enforce a call from an inherited constructor to a specific base constructor?
Yes, just place a colon, and then keyword base (parameter list to invoke the appropriate constructor) in the overloaded constructor definition inside the inherited class.
Events and Delegates
Whats a delegate?
A delegate object encapsulates a reference to a method.
Whats a multicast delegate?
A delegate that has multiple handlers assigned to it. Each assigned handler (method) is called.
XML Documentation Questions
Is XML case-sensitive?
Yes.
Whats the difference between // comments, /* */ comments and /// comments?
Single-line comments, multi-line comments, and XML documentation comments.
How do you generate documentation from the C# file commented properly with a command-line compiler?
Compile it with the /doc switch.
Debugging and Testing Questions
What debugging tools come with the .NET SDK?
1. CorDBG command-line debugger. To use CorDbg, you must compile the original C# file using the /debug switch.
2. DbgCLR graphic debugger. Visual Studio .NET uses the DbgCLR.
What does assert() method do?
In debug compilation, assert takes in a Boolean condition as a parameter, and shows the error dialog if the condition is false. The program proceeds without any interruption if the condition is true.
Whats the difference between the Debug class and Trace class?
Documentation looks the same. Use Debug class for debug builds, use Trace class for both debug and release builds.
Why are there five tracing levels in System.Diagnostics.TraceSw
itcher?
The tracing dumps can be quite verbose. For applications that are constantly running you run the risk of overloading the machine and the hard drive. Five levels range from None to Verbose, allowing you to fine-tune the tracing activities.
Where is the output of TextWriterTraceListener redirected?
To the Console or a text file depending on the parameter passed to the constructor.
How do you debug an ASP.NET Web application?
Attach the aspnet_wp.exe process to the DbgClr debugger.
What are three test cases you should go through in unit testing?
1. Positive test cases (correct data, correct output).
2. Negative test cases (broken or missing data, proper handling).
3. Exception test cases (exceptions are thrown and caught properly).
Can you change the value of a variable while debugging a C# application?
Yes. If you are debugging via Visual Studio.NET, just go to Immediate window.
ADO.NET and Database Questions
What is the role of the DataReader class in ADO.NET connections?
It returns a read-only, forward-only rowset from the data source. A DataReader provides fast access when a forward-only sequential read is needed.
What are advantages and disadvantages of Microsoft-provided data provider classes in ADO.NET?
SQLServer.NET data provider is high-speed and robust, but requires SQL Server license purchased from Microsoft. OLE-DB.NET is universal for accessing other sources, like Oracle, DB2, Microsoft Access and Informix. OLE-DB.NET is a .NET layer on top of the OLE layer, so its not as fastest and efficient as SqlServer.NET.
What is the wildcard character in SQL?
Lets say you want to query database with LIKE for all employees whose name starts with La. The wildcard character is %, the proper query with LIKE would involve La%.
Explain ACID rule of thumb for transactions.
A transaction must be:
1. Atomic - it is one unit of work and does not dependent on previous and following transactions.
2. Consistent - data is either committed or roll back, no in-between case where something has been updated and something hasnt.
3. Isolated - no transaction sees the intermediate results of the current transaction).
4. Durable - the values persist if the data had been committed even if the system crashes right after.
What connections does Microsoft SQL Server support?
Windows Authentication (via Active Directory) and SQL Server authentication (via Microsoft SQL Server username and password).
Between Windows Authentication and SQL Server Authentication, which one is trusted and which one is untrusted?
Windows Authentication is trusted because the username and password are checked with the Active Directory, the SQL Server authentication is untrusted, since SQL Server is the only verifier participating in the transaction.
What does the Initial Catalog parameter define in the connection string?
The database name to connect to.
What does the Dispose method do with the connection object?
Deletes it from the memory.
To Do: answer better. The current answer is not entirely correct.
What is a pre-requisite for connection pooling?
Multiple processes must agree that they will share the same connection, where every parameter is the same, including the security settings. The connection string must be identical.
Assembly Questions
How is the DLL Hell problem solved in .NET?
Assembly versioning allows the application to specify not only the library it needs to run (which was available under Win32), but also the version of the assembly.
What are the ways to deploy an assembly?
An MSI installer, a CAB archive, and XCOPY command.
What is a satellite assembly?
When you write a multilingual or multi-cultural application in .NET, and want to distribute the core application separately from the localized modules, the localized assemblies that modify the core application are called satellite assemblies.
What namespaces are necessary to create a localized application?
System.Globalization and System.Resources.
What is the smallest unit of execution in .NET?
an Assembly.
When should you call the garbage collector in .NET?
As a good rule, you should not call the garbage collector. However, you could call the garbage collector when you are done using a large object (or set of objects) to force the garbage collector to dispose of those very large objects from memory. However, this is usually not a good practice.
How do you convert a value-type to a reference-type?
Use Boxing.
What happens in memory when you Box and Unbox a value-type?
Boxing converts a value-type to a reference-type, thus storing the object on the heap. Unboxing converts a reference-type to a value-type, thus storing the value on the stack.
Explain the differences between Server-side and Client-side code?
ANS: Server side code will execute at server end all the business logic will execute at server end where as client side code will execute at client side at browser end.
What type of code (server or client) is found in a Code-Behind class?
ANS : Server side.
3. Should validation (did the user enter a real date) occur server-side or client-side? Why?
ANS : client side . there is no need to go to validate user input. If it relates to data base validation we need to validate at server side.
4. What does the "EnableViewState" property do? Why would I want it on or off?
ANS: IT keeps the data of the control during post backs.
if we turn off the values should not populate during server round trip.
5. What is the difference between Server.Transfer and
Response.Redirect? Why would I choose one over the other?
ANS: Server.Trnasfer will prevent round trip. it will redirect pages which or in the same directory. NO way to pass the query strings . Thru http context we can able to get the previous page control values.
Response.Redirect : There is a round trip to process the request. We can redirect to any page external / internal other than aspx. We can pass the query string thru which we can manage sessions.
6. Can you give an example of when it would be appropriate to use a web service as opposed to a non-serviced .NET component
ANS : Web services are best suite for Hetrogenious environment.Remoting is best suite for Homogenious environment. The systems that under CLR.
7. Let's say I have an existing application written using Visual Studio 6 (VB 6, InterDev 6) and this application utilizes Windows 2000 COM+ transaction services. How would you approach migrating this application to .NET We need to have Wrapper to communicate COM components in .net. and vis versa CCW : Com Callable wrapper. RCW : RUN time callable wrapper.
8. Can you explain the difference between an ADO.NET Dataset and anADO Recordset?\
ANS : DIsconnected architechure . Maintainace relation schemas. MUtilple table grouping.
Connected one .
9. Can you give an example of what might be best suited to place in the Application_Start and Session_Start subroutines?
ANS: APplication_start need for global variable which are available over the application. Sesssion_Start : login dependent ( user dependent)
10. If I'm developing an application that must accomodate multiple security levels though secure login and my ASP.NET web appplication is spanned across three web-servers (using round-robbin load balancing) what would be the best approach to maintain login-in state for The users?
ANS : Database Support. or Thru state service.
11. What are ASP.NET Web Forms? How is this technology different than what is available though ASP (1.0-3.0)?
ANS : ASP . Interprepter.. use the script engine. ASP.Net Compiled.
12. How does VB.NET/C# achieve polymorphism?
ANS : Function overloading. Operator overloading.
11. Can you explain what inheritance is and an example of when you might use it?
ANS : Heridity. Use the existing functionality along with its own properities.
13. How would you implement inheritance using VB.NET/C#?
ANS: Derived Class : Basecalss VB.NEt : Derived Class Inherits Baseclass
14. Whats an assembly
ANS : A Basic unit of executable code > Which contains : Manifest - Meta data versioning , Calture , IL, Reference
15. Describe the difference between inline and code behind - which is best in a loosely coupled solution Tightly coupled - INLINE
ANS: inline function bind at compile time can write in aspx page with in <% %> .
17. Explain what a diffgram is, and a good use for one
ANS : is an xml grammer. it talk about state of node in xml file.
18. Where would you use an iHTTPModule, and what are the limitations of any approach you might take in implementing one
ANS: Preprocessing before going to IIS.
20. What are the disadvantages of viewstate/what are the benefits
ANS : IT can be hacked . page is size is heavy.
21 Describe session handling in a webfarm, how does it work and what are the limits
ANS:Session - mode State sever OUtprocess sql
22. How would you get ASP.NET running in Apache web servers - why would you even do this?
ANS: ---- Install Mod_AspDotNet
Add at the end of C:\Program Files\Apache Group\Apache2\conf\httpd.c
onf the following lines
23. Whats MSIL, and why should my developers need an appreciation of it if at all?
ANS : Microsoft Intermeidate lanaguage. which is the out put for all the .net supported languages after comiplation will produce.
Appreciation for cross language support.
24. In what order do the events of an ASPX page execute. As a developer is it important to undertsand these events?
ANS : INIT, PageLoad, Prerender , UNload.
25. Which method do you invoke on the DataAdapter control to load your generated dataset with data?
Fill()
26. Can you edit data in the Repeater control?
NO
27. Which template must you provide, in order to display data in a Repeater control?
ITemtemplate
28. How can you provide an alternating color scheme in a Repeatercontrol?
AlternateItemTemplate
29. What property must you set, and what method must you call in your code, in order to bind the data from some data source to the Repeatercontrol?
Datasource, DataBind
30. What base class do all Web Forms inherit from?
System.Web.UI.Page
31. What method do you use to explicitly kill a user s session?
abondon()
32 How do you turn off cookies for one page in your site?
disablecookies.
33. Which two properties are on every validation control?
control to validate, error message
34. What tags do you need to add within the asp:datagrid tags to bind columns manually?
autogenerated columns is set to false
35. How do you create a permanent cookie?
Cooke = ne cookee(). cooke.adddate.
36. What tag do you use to add a hyperlink column to the DataGrid?
hyper link column
37. What is the standard you use to wrap up a call to a Web service
------------
38. Which method do you use to redirect the user to another page without performing a round trip to the client?
server.transfer
39. What is the transport protocol you use to call a Web service SOAP
http
40. True or False: A Web service can only be written in .NET
false
41. What does WSDL stand for? webservice discription language. it is used to generate for proxy( server object)
42. What property do you have to set to tell the grid which page to go to when using the Pager object?
Page Index.
43. Where on the Internet would you look for Web services?
UDDI
44. What tags do you need to add within the asp:datagrid tags to bind columns manually.
Autogenerate columns
45. Which property on a Combo Box do you set with a column name, prior to setting the DataSource, to display data in the combo box?
datatext
datavalue
46. How is a property designated as read-only?
get
47. Which control would you use if you needed to make sure the values in two different controls matched?
compare filed validator
48. True or False: To test a Web service you must create a windows application or Web application to consume this service?
no
49. How many classes can a single .NET DLL contain?
as many as u want..
-------------------
Whats the advantage of using System.Text.StringBuilder over System.String? StringBuilder is more efficient in the cases, where a lot of manipulation is done to the text. Strings are immutable, so each time its being operated on, a new instance is created.
Can you store multiple data types in System.Array? No.
Whats the difference between the System.Array.CopyTo() and System.Array.Clone()? The first one performs a deep copy of the array, the second one is shallow.
How can you sort the elements of the array in descending order? By calling Sort() and then Reverse() methods.
Whats the .NET datatype that allows the retrieval of data by a unique key? HashTable.
Whats class SortedList underneath? A sorted HashTable.
Will finally block get executed if the exception had not occurred? Yes.
Whats the C# equivalent of C++ catch (&), which was a catch-all statement for any possible exception? A catch block that catches the exception of type System.Exception. You can also omit the parameter data type in this case and just write catch {}.
Can multiple catch blocks be executed? No, once the proper catch code fires off, the control is transferred to the finally block (if there are any), and then whatever follows the finally block.
Why is it a bad idea to throw your own exceptions? Well, if at that point you know that an error has occurred, then why not write the proper code to handle that error instead of passing a new Exception object to the catch block? Throwing your own exceptions signifies some design flaws in the project.
Whats a delegate? A delegate object encapsulates a reference to a method. In C++ they were referred to as function pointers.
Whats a multicast delegate? Its a delegate that points to and eventually fires off several methods.
Hows the DLL Hell problem solved in .NET? Assembly versioning allows the application to specify not only the library it needs to run (which was available under Win32), but also the version of the assembly.
What are the ways to deploy an assembly? An MSI installer, a CAB archive, and XCOPY command.
Whats a satellite assembly? When you write a multilingual or multi-cultural application in .NET, and want to distribute the core application separately from the localized modules, the localized assemblies that modify the core application are called satellite assemblies.
What namespaces are necessary to create a localized application? System.Globalization, System.Resources.
Whats the difference between // comments, /* */ comments and /// comments? Single-line, multi-line and XML documentation comments.
How do you generate documentation from the C# file commented properly with a command-line compiler? Compile it with a /doc switch.
Whats the difference between
and XML documentation tag? Single line code example and multiple-line code example.
Is XML case-sensitive? Yes, so and are different elements.
What debugging tools come with the .NET SDK? CorDBG command-line debugger, and DbgCLR graphic debugger. Visual Studio .NET uses the DbgCLR. To use CorDbg, you must compile the original C# file using the /debug switch.
What does the This window show in the debugger? It points to the object thats pointed to by this reference. Objects instance data is shown.
What does assert() do? In debug compilation, assert takes in a Boolean condition as a parameter, and shows the error dialog if the condition is false. The program proceeds without any interruption if the condition is true.
Whats the difference between the Debug class and Trace class? Documentation looks the same. Use Debug class for debug builds, use Trace class for both debug and release builds.
Why are there five tracing levels in System.Diagnostics.TraceSwitcher? The tracing dumps can be quite verbose and for some applications that are constantly running you run the risk of overloading the machine and the hard drive there. Five levels range from None to Verbose, allowing to fine-tune the tracing activities.
Where is the output of TextWriterTraceListener redirected? To the Console or a text file depending on the parameter passed to the constructor.
How do you debug an ASP.NET Web application? Attach the aspnet_wp.exe process to the DbgClr debugger.
What are three test cases you should go through in unit testing? Positive test cases (correct data, correct output), negative test cases (broken or missing data, proper handling), exception test cases (exceptions are thrown and caught properly).
Can you change the value of a variable while debugging a C# application? Yes, if you are debugging via Visual Studio.NET, just go to Immediate window.
Explain the three services model (three-tier application). Presentation (UI), business (logic and underlying code) and data (from storage or other sources).
What are advantages and disadvantages of Microsoft-provided data provider classes in ADO.NET? SQLServer.NET data provider is high-speed and robust, but requires SQL Server license purchased from Microsoft. OLE-DB.NET is universal for accessing other sources, like Oracle, DB2, Microsoft Access and Informix, but its a .NET layer on top of OLE layer, so not the fastest thing in the world. ODBC.NET is a deprecated layer provided for backward compatibility to ODBC engines.
Whats the role of the DataReader class in ADO.NET connections? It returns a read-only dataset from the data source when the command is executed.
What is the wildcard character in SQL? Lets say you want to query database with LIKE for all employees whose name starts with La. The wildcard character is %, the proper query with LIKE would involve La%.
Explain ACID rule of thumb for transactions. Transaction must be Atomic (it is one unit of work and does not dependent on previous and following transactions), Consistent (data is either committed or roll back, no in-between case where something has been updated and something hasnt), Isolated (no transaction sees the intermediate results of the current transaction), Durable (the values persist if the data had been committed even if the system crashes right after).
What connections does Microsoft SQL Server support? Windows Authentication (via Active Directory) and SQL Server authentication (via Microsoft SQL Server username and passwords).
Which one is trusted and which one is untrusted? Windows Authentication is trusted because the username and password are checked with the Active Directory, the SQL Server authentication is untrusted, since SQL Server is the only verifier participating in the transaction.
Why would you use untrusted verificaion? Web Services might use it, as well as non-Windows applications.
What does the parameter Initial Catalog define inside Connection String? The database name to connect to.
Whats the data provider name to connect to Access database? Microsoft.Access.
What does Dispose method do with the connection object? Deletes it from the memory.
What is a pre-requisite for connection pooling? Multiple processes must agree that they will share the same connection, where every parameter is the same, including the security settings.
Interview Questions
ASP.NET
Describe the role of inetinfo.exe, aspnet_isapi.dll andaspnet_wp.exe in the page loading process. inetinfo.exe is theMicrosoft IIS server running, handling ASP.NET requests among other things.When an ASP.NET request is received (usually a file with .aspx extension),the ISAPI filter aspnet_isapi.dll takes care of it by passing the request tothe actual worker process aspnet_wp.exe.
Whats the difference between Response.Write() andResponse.Output.Write()? The latter one allows you to write formattedoutput.
What methods are fired during the page load? Init() - when the pageis instantiated, Load() - when the page is loaded into server memory,PreRender() - the brief moment before the page is displayed to the user asHTML, Unload() - when page finishes loading.
Where does the Web page belong in the .NET Framework class hierarchy?System.Web.UI.Page
Where do you store the information about the users locale? System.Web.UI.Page.Culture
Whats the difference between Codebehind="MyCode.aspx.cs" andSrc="MyCode.aspx.cs"? CodeBehind is relevant to Visual Studio.NET only.
Whats a bubbled event? When you have a complex control, like DataGrid, writing an event processing routine for each object (cell, button, row, etc.) is quite tedious. The controls can bubble up their eventhandlers, allowing the main DataGrid event handler to take care of its constituents.
Suppose you want a certain ASP.NET function executed on MouseOver overa certain button. Where do you add an event handler? Its the Attributesproperty, the Add function inside that property. So btnSubmit.Attributes.Add("onMouseOver","someClientCode();")
What data type does the RangeValidator control support? Integer,String and Date.
Explain the differences between Server-side and Client-side code? Server-side code runs on the server. Client-side code runs in the clients browser.
What type of code (server or client) is found in a Code-Behind class? Server-side code.
Should validation (did the user enter a real date) occur server-side or client-side? Why? Client-side. This reduces an additional request to the server to validate the users input.
What does the "EnableViewState" property do? Why would I want it on or off? It enables the viewstate on the page. It allows the page to save the users input on a form.
What is the difference between Server.Transfer and Response.Redirect? Why would I choose one over the other? Server.Transfer is used to post a form to another page. Response.Redirect is used to redirect the user to another page or site.
Can you explain the difference between an ADO.NET Dataset and an ADO Recordset?
A DataSet can represent an entire relational database in memory, complete with tables, relations, and views.
A DataSet is designed to work without any continuing connection to the original data source.
. Data in a DataSet is bulk-loaded, rather than being loaded on demand.
There's no concept of cursor types in a DataSet.
DataSets have no current record pointer You can use For Each loops to move through the data.
You can store many edits in a DataSet, and write them to the original data source in a single operation.
Though the DataSet is universal, other objects in ADO.NET come in different versions for different data sources
Can you give an example of what might be best suited to place in the Application_Start and Session_Start subroutines? This is where you can set the specific variables for the Application and Session objects.
If Im developing an application that must accommodate multiple security levels though secure login and my ASP.NET web application is spanned across three web-servers (using round-robin load balancing) what would be the best approach to maintain login-in state for the users? Maintain the login state security through a database.
Can you explain what inheritance is and an example of when you might use it? When you want to inherit (use the functionality of) another class. Base Class Employee. A Manager class could be derived from the Employee base class.
Whats an assembly? Assemblies are the building blocks of the .NET framework. Overview of assemblies from MSDN
Describe the difference between inline and code behind. Inline code written along side the html in a page. Code-behind is code written in a separate file and referenced by the .aspx page.
Explain what a diffgram is, and a good use for one? The DiffGram is one of the two XML formats that you can use to render DataSet object contents to XML. For reading database data to an XML file to be sent to a Web Service.
Whats MSIL, and why should my developers need an appreciation of it if at all? MSIL is the Microsoft Intermediate Language. All .NET compatible languages will get converted to MSIL.
Which method do you invoke on the DataAdapter control to load your generated dataset with data? The .Fill() method
Can you edit data in the Repeater control? No, it just reads the information from its data source
Which template must you provide, in order to display data in a Repeater control? ItemTemplate
How can you provide an alternating color scheme in a Repeater control? Use the AlternatingItemTemplate
What property must you set, and what method must you call in your code, in order to bind the data from some data source to the Repeater control? You must set the DataSource property and call the DataBind method.
What base class do all Web Forms inherit from? The Page class.
Name two properties common in every validation control? ControlToValidate property and Text property.
What tags do you need to add within the asp:datagrid tags to bind columns manually? Set AutoGenerateColumns Property to false on the datagrid tag
What tag do you use to add a hyperlink column to the DataGrid?
What is the transport protocol you use to call a Web service? SOAP is the preferred protocol.
True or False: A Web service can only be written in .NET? False
What does WSDL stand for? (Web Services Description Language)
Where on the Internet would you look for Web services? (http://www.uddi.org)
Which property on a Combo Box do you set with a column name, prior to setting the DataSource, to display data in the combo box? DataTextField property
Which control would you use if you needed to make sure the values in two different controls matched? CompareValidator Control
True or False: To test a Web service you must create a windows application or Web application to consume this service? False, the webservice comes with a test page and it provides HTTP-GET method to test.
How many classes can a single .NET DLL contain? It can contain many classes.
