Technology Questions

Cursors help you manipulate the information retrieved by select statements. This can be done by assigning a name to the cursor.

Example:

CURSOR emp_cur 

IS 

SELECT emp_number from employee_tbl where employee_name = name_in;

Types of Cursors:

Implicit cursors- These cursors are not declared by the programmer. They are issued when the SQL statement is executed. The open, close and fetching is done by itself.

Example:

UPDATE employee SET salary = salary * 2.1;

Here, an implicit cursor is issued to identify the set of rows in the table which would be affected by the update.

Explicit cursors- These cursors are defined by programmer. They are used in queries that return multiple rows.

Example:

CURSOR emp_cur 

IS 

SELECT emp_number from employee_tbl where employee_name = name_in;

A thread can be created by subclassing Thread, or by implementing the Runnable interface.

Research in Motion, a Canadian company provided a proprietary operating system for BlackBerry.

The operating system provides support for Java MIDP 1.0 and WAP 1.2.

The current version supports Novell Group Wise and Lotus Notes.

Third-party software can be developed using BlackBerry APIs as well, with certain restriction functionality must be signed by RIM digitally, so that it can be associated to a developer account. 

- The principle of least privilege is used to provide more security to the computer programs. 

- The principle allows the designing of the program such that any unauthorized access is not allowed and only the person who owns the program will be able to access it. 

- The services provided should be able to access only those products that need the services. 

- Web servers that are involved in responding the queries of the web users provide only accessing to the HTML files that will serve the purpose of the programs. 

- Computer programs should be made such that it provides secure features of logging into the program with proper authentication.

Android uses Dalvik Virtual Machine (DVM) which requires a special bytecode. We need to convert Java class files into Dalvik Executable files using an Android tool called "dx". In normal circumstances, developers will not be using this tool directly and build tools will care for the generation of DVM compatible files.

The UTL_FILE database package can be used to read and write operating system files. You need to have read /write access rights in that directory before the package can be used.

Example to write file:

Fhandler is a variable of type UTL_FILE.FILE_TYPE

UTL_FILE.PUTF(fHandler, 'Im writing to a file\n');

Example to read file:

UTL_FILE.GET_LINE(fHandler, buf);

FIND_GROUP(function) FIND_COLUMN(function)

Array is collection of same data type. Array size is fixed, It cannot be expanded.

But ArrayList is a growable collection of objects.ArrayList is a part of Collections Framework and can work with only objects.