Technology Questions

As far PHP concern it only support single Inheritance in scripting. we can also use interface to achieve multiple inheritance.

A31. The self-referencing constraint limits in a single table the changes to a primary key that the related foreign key defines. The foreign key in a self referencing table must specify the DELETE CASCADE rule.

You should not use AJAX if:

             =>  You want the page to show in a search engine, such as Google, because WebCrawler does not execute JavaScript code.

             =>  The browser does not support JavaScript.

             =>  You want to create a secure application.

Generally a business analyst covers several stages in Software Development Life Cycle.

Like:  Client Consulting, Client Requirement Study, Planning for business needs, Business Requirement Documenting, Work on functional requirement, Prepare test data with inputs from end users, Document use case scenarios, Help Testing team with test plan and testing, Help end users with user acceptance testing UAT, Go live and post production support tasks.

A collection just like an array is an ordered group of elements of the same type. Each elements position is determined by a unique subscript.

Index by tables:- They are similar to hash arrays that allows to search for subscript values using arbitrary numbers and strings.

They can be declared as:

TYPE type_name IS TABLE OF element_type [NOT NULL]

INDEX BY [BINARY_INTEGER | PLS_INTEGER | VARCHAR2(size_limit)];

INDEX BY key_type;

Example:

TYPE studenttyp IS TABLE OF emp%ROWTYPE

INDEX BY BINARY_INTEGER;

stud_tab studenttyp;

Nested tables:- they hold random number of elements and use sequential numbers as sub scripts.

They can be declared as:

TYPE type_name IS TABLE OF element_type [NOT NULL];

Example: TYPE employee_type IS TABLE OF NUMBER INDEX BY VARCHAR2(64);

Varrays: Holds a fixed number of elements which can be changed in run time. 

They can be declared as:

TYPE type_name IS {VARRAY | VARYING ARRAY} (size_limit) OF element_type [NOT NULL];

Example: TYPE Calendar IS VARRAY(366) OF DATE;

Java applications can call code written in C, C++, or assembler. This is sometimes done for performance and sometimes to access the underlying host operating system or GUI API using the JNI.

The steps for doing that are:

First write the Java code and compile it

Then create a C header file

Create C stubs file

Write the C code

Create shared code library (or DLL)

Run application

The flow chart gives a clear graphical representation of an implemented process. This makes the system simple to understand for all persons involved in the project. 

SQL is a structured query language while PL/SQL is an extension of SQL by introducing a procedural flow. PL/SQL has blocks of statements. PL/SQL works like other procedural languages and has concepts like control statements, sequential statements, exception handling etc.