Technology Questions

A unique constraint on a column uniquely identifies the record by a combination of one or more fields. Few unique constraint fields can have a NULL value as long as the combination of values is unique.

Example:
create table employee ( id number NOT NULL, dob DATE, professor_id NOT NULL, Name varchar(200) Constraint id_unique UNIQUE(id,dob) );

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);

The JVM performs three main tasks:

• Loads code

• Verifies code

• Executes code

- Frames make it easier to navigate through a site. 

- The links that appear in the frame can appear through out the site.

switches are configured using the .config file

<system.diagnostics>

<switches>

<add name="MyTraceSwitch" value="1" />

<add name="TraceSwitch2" value="1" />

</switches>

</system.diagnostics>

both are on.

A NSArray’s contents can not be modified once it’s been created whereas a NSMutableArray can be modified as needed, i.e items can be added/removed from it.

Client side java script comprises the basic language and predefined objects which are relevant to running java script in a browser. The client side java script is embedded directly by in the HTML pages. This script is interpreted by the browser at run time.

Server side java script also resembles like client side java script. It has relevant java script which is to run in a server. The server side java scripts are deployed only after compilation.

strat_form using this we can open many layoutses
open_form using this we can open the layout
performance will be high