ASP.NET Question And Answer 4

ADO.Net
1. Command object (ExecuteNonquery, ExecuteReader, ExecuteXM LRead er,
ExecuteScalar)
2. DataAdapter object (Fill)
3. Dataset (collection of tables)
4. CommandBuiler object
5. Transaction Object
6. Isolation levels
Q: What are the most common techniques for reusing functionality in object-
oriented systems?
A: The two most common techniques for reusing functionality in object-oriented systems
are class inheritance and object composition.
Class inheritance lets you define the implementation of one class in terms of another's.
Reuse by subclassing is often ref erred to as white-box reuse.
Object composition is an alternative to class inheritance. Here, new functionality is
obtained by assembling or composing objects to get more complex functionality. This is
known as black-box reuse.
Q: Why would you want to have more than one catch block associated with a single
try block in Java?
A: Since there are many things can go wron g to a single executed statement, we should
have more than one catch(s) to catch any er rors that might occur.
Q: What language is used by a relational model to describe the structure of a
database?
A: The Data Definition Language.
Q: What is JSP? Describe its concept.
A: JSP is the JavaServer Page. The JavaServer Page concept is to provide an HTM L
document with the ability to plug in content at selected locations in the document. (This
content is then supplied by the W eb server along with the rest of the HTM L document at
the time the document is downloaded).
Q: What does the JSP engine do when presented with a JavaServer Page to process?
A: The JSP engine builds a servlet. The HTM L portions of the JavaServer Page become
Strings transmitted to print methods of a PrintW riter object. The JSP tag portions result in
calls to methods of the appropriate JavaBean class whose output is translated into more
calls to a println method to place the result in the HTML do cument