Hema: PHP Interview Questions and Answers

Questions : 1 What is Full form of PHP ? Who is the father or inventor of PHP ?

Answers : 1 Rasmus Lerdorf is known as the father of PHP that started development of PHP in 1994
for their own Personal Home Page (PHP) and they released PHP/FI (Forms Interpreter) version 1.0 publicly on 8 June 1995 But in 1997 two Israeli developers named Zeev Suraski and Andi Gutmans rewrote the parser that formed the base of PHP 3 and then changed the language's name to the PHP: Hypertext Preprocessor.

Questions : 2 What are the differences between PHP3 and PHP4 and PHP5 ? what is the current stable version of PHP ? what advance thing in php7

Answers : 2

The current stable version of PHP is PHP 5.6.0 on 2014-08-28 with new Constant scalar expressions, variadic functions, exponentiation operator, argument unpacking, extensions of the use statement for functions and constants, new phpdbg debugger as a SAPI module etc. as still waiting for PHP6 or PHP7 with unicode handlig thing
There are lot of difference among PHP3 and PHP4 and PHP5 version of php so Difference mean oldest version have less functionality as compare to new one like

There are lot of difference among PHP3 and PHP4 and PHP5 version of php as PHP6 is till in under development process so we are geting Difference mean oldest version have less functionality as compare to new one like below point

A> PHP3 is oldest stable version and it was pure procedural language constructive like C
B> Where as PHP4 have some OOPs concept added like class and object with new functionality
C> and in PHP5 approximately all major oops functionality has been added along with below thing
1. Implementation of exceptions and exception handling
2. Type hinting which allows you to force the type of a specific argument
3. Overloading of methods through the __call function
4. Full constructors and destructors etc through a __constuctor and __destructor function
5. __autoload function for dynamically including certain include files depending on the class you are trying to create.
6 Finality : can now use the final keyword to indicate that a method cannot be overridden by a child. You can also declare an entire class as final which prevents it from having any children at all.
7 Interfaces & Abstract Classes
8 Passed by Reference :
9 An __clone method if you really want to duplicate an object
10 Numbers of Functions Deprecated or removed in PHP 5.x like ereg,ereg_replace,magic_quotes, session_register,register_globals, split(), call_user_method() etc

Questions : 3 Is variable name casesensitive ? could we start a variable with number like $4name ? What is the difference between $name and $$name? How to swap two variables without using 3rd temp variable

Answer : 3 Yes variable name casesensitive and we can not start a variable with number like $4name as A valid variable name starts with a letter or underscore, followed by any number of letters, numbers, or underscores.
where as $$ is variable of variable $name is variable where as $$name is variable of variable
like $name=sonia and $$name=singh so $sonia value is singh.
we can swap two variables by adding and subtracting method like below
$a=10,$b=5;
$a=$b+$a;//means $a=15 here
$b=$a-$b; //means $b=15-5=10
$a=$a-$b;// means $a=15-10=5

Questions : 4 What is use of header() function in php ? What the Limitation of HEADER()?

Answers : 4

In PHP Important to notice the Limitation of HEADER() function is that header() must be called before any actual output is send. Means must use header function before HTML or any echo stateament There are Number of Use of HEADER() function in php like below
1> The header() function use to sends a raw HTTP header to a client.
2> We can use herder() function for redirection of pages.
3> Use for refresh the page on given time interval automatically.
4> To send email header content like cc, bcc , reply to etc data and lot more .

There are various use of HEADER Function in PHP and HTTP like URL redirect , refresh, 301 redirection permanently etc so here PCDs provide questions and answers with example on all type of header function used in PHP

Top header function interview questions and answers

Questions : 1	Can we include header fuction in between HTML output of php page
Answers : 1	No, We can't use header function in between any out put because it generate error if any out put like any content, white space, line , any tag like < html > etc send before header function so we must use header function befor any Out Put Send.

Questions : 2	How we can redirect a page to other page or site using php header
Answers : 2	We can use header function like below to redirect header('Location: http://www.pcds.co.in/'); at place of pcds.co.in we can write any site name or any internal page like header('Location: blog.php'); and must there should not any space between Location and : and http status code of this redirection is 302

Questions : 3	How we can do permanent redirect 301 a page to other page or site using php header
Answer : 3	by below code we can do permanent redirect 301 header("Location: /blog.php",TRUE,301); OR header('HTTP/1.1 301 Moved Permanently'); header('Location: http://www.pcds.co.in/');

Questions : 4	How we can sent HTTP status using header funcion
Answer : 4	we can send HTTP status by below type of code header("HTTP/1.0 404 Not Found"); Below are the use of header function header php header location in php location header php header location php

Questions : 5 How can we extract string "pcds.co.in" from a string "http://info@pcds.co.in" using regular expression of PHP? More on Reg can you explain

Answers : 5

We can extract string "pcds.co.in" using this
preg_match("/^http:\/\/.+@(.+)$/","http://info@pcds.co.in",$matches);
echo $matches[1];
More On regular expression interview question with very nice examples in
Regular Expressions Interview questions and answers for all language like PHP, Java, .net etc developer with lot of examples of complex search pattern and rewrite rules in Apache and .htaccess

Mysql interview questions and answers are below

Questions : 1	how to do login in mysql with unix shell
Answers :1	By below method if password is pass and user name is root # [mysql dir]/bin/mysql -h hostname -u root -p pass

Questions : 2	how you will Create a database on the mysql server with unix shell
Answers : 2	mysql> create database databasename;

Questions : 3	how to list or view all databases from the mysql server.
Answers : 3	mysql> show databases;

Questions : 4	How Switch (select or use) to a database.
Answers : 4	mysql> use databasename;

Questions : 5	How To see all the tables from a database of mysql server.
Answers : 5	mysql> show tables;

Questions : 6	How to see table's field formats or description of table .
Answers : 6	mysql> describe tablename;

Questions : 7	How to delete a database from mysql server.
Answers : 7	mysql> drop database databasename;

Questions : 8	How we get Sum of column
Answers : 8	mysql> SELECT SUM(*) FROM [table name];

Questions : 9	How to delete a table
Answers : 9	mysql> drop table tablename;

Questions : 10	How you will Show all data from a table.
Answers : 10	mysql> SELECT * FROM tablename;

Questions : 11	How to returns the columns and column information pertaining to the designated table
Answers :	mysql> show columns from tablename;

Questions : 12	How to Show certain selected rows with the value "pcds"
Answers : 12	mysql> SELECT * FROM tablename WHERE fieldname = "pcds";

Questions : 13	How will Show all records containing the name "sonia" AND the phone number '9876543210'
Answers : 13	mysql> SELECT * FROM tablename WHERE name = "sonia" AND phone_number = '9876543210';

Questions : 14	How you will Show all records not containing the name "sonia" AND the phone number '9876543210' order by the phone_number field.
Answer : 14	mysql> SELECT * FROM tablename WHERE name != "sonia" AND phone_number = '9876543210' order by phone_number;

Questions : 15	How to Show all records starting with the letters 'sonia' AND the phone number '9876543210'
Answers : 15	mysql> SELECT * FROM tablename WHERE name like "sonia%" AND phone_number = '9876543210';

Questions : 16	How to show all records starting with the letters 'sonia' AND the phone number '9876543210' limit to records 1 through 5.
Answers : 16	mysql> SELECT * FROM tablename WHERE name like "sonia%" AND phone_number = '9876543210' limit 1,5;

Questions : 16	Use a regular expression to find records. Use "REGEXP BINARY" to force case-sensitivity. This finds any record beginning with r.
Answer : 16	mysql> SELECT * FROM tablename WHERE rec RLIKE "^r";

Questions : 17	How you will Show unique records.
Answer : 17	mysql> SELECT DISTINCT columnname FROM tablename;

Questions : 18	how we will Show selected records sorted in an ascending (asc) or descending (desc)
Answer : 18	mysql> SELECT col1,col2 FROM tablename ORDER BY col2 DESC; mysql> SELECT col1,col2 FROM tablename ORDER BY col2 ASC;

Questions : 19	how to Return total number of rows.
Answers : 19	mysql> SELECT COUNT(*) FROM tablename;

Questions : 20	How to Join tables on common columns.
Answer : 20	mysql> select lookup.illustrationid, lookup.personid,person.birthday from lookup left join person on lookup.personid=person.personid=statement to join birthday in person table with primary illustration id

Questions : 21	How to Creating a new user. Login as root. Switch to the MySQL db. Make the user. Update privs.
Answer : 21	# mysql -u root -p mysql> use mysql; mysql> INSERT INTO user (Host,User,Password) VALUES('%','username',PASSWORD('password')); mysql> flush privileges;

Questions : 22	How to Change a users password from unix shell.
Answers : 22	# [mysql dir]/bin/mysqladmin -u username -h hostname.blah.org -p password 'new-password'

Questions : 23	How to Change a users password from MySQL prompt. Login as root. Set the password. Update privs.
Answer : 23	# mysql -u root -p mysql> SET PASSWORD FOR 'user'@'hostname' = PASSWORD('passwordhere'); mysql> flush privileges;

Questions : 24	How to Recover a MySQL root password. Stop the MySQL server process. Start again with no grant tables. Login to MySQL as root. Set new password. Exit MySQL and restart MySQL server.
Answer : 24	# /etc/init.d/mysql stop # mysqld_safe --skip-grant-tables & # mysql -u root mysql> use mysql; mysql> update user set password=PASSWORD("newrootpassword") where User='root'; mysql> flush privileges; mysql> quit # /etc/init.d/mysql stop # /etc/init.d/mysql start

Questions : 25	How to Set a root password if there is on root password.
Answer : 25	# mysqladmin -u root password newpassword

Questions : 26	How to Update a root password.
Answer : 26	# mysqladmin -u root -p oldpassword newpassword

Questions : 27	How to allow the user "sonia" to connect to the server from localhost using the password "passwd". Login as root. Switch to the MySQL db. Give privs. Update privs.
Answers : 27	# mysql -u root -p mysql> use mysql; mysql> grant usage on . to sonia@localhost identified by 'passwd'; mysql> flush privileges;

Questions : 28	How to give user privilages for a db. Login as root. Switch to the MySQL db. Grant privs. Update privs.
Answers : 28	# mysql -u root -p mysql> use mysql; mysql> INSERT INTO user (Host,Db,User,Select_priv,Insert_priv,Update_priv,Delete_priv,Create_priv,Drop_priv) VALUES ('%','databasename','username','Y','Y','Y','Y','Y','N'); mysql> flush privileges; or mysql> grant all privileges on databasename.* to username@localhost; mysql> flush privileges;

Questions : 29	How To update info already in a table and Delete a row(s) from a table.
Answer : 29	mysql> UPDATE [table name] SET Select_priv = 'Y',Insert_priv = 'Y',Update_priv = 'Y' where [field name] = 'user'; mysql> DELETE from [table name] where [field name] = 'whatever';

Questions : 30	How to Update database permissions/privilages.
Answer : 30	mysql> flush privileges;

Questions : 31	How to Delete a column and Add a new column to database
Answer : 31	mysql> alter table [table name] drop column [column name]; mysql> alter table [table name] add column [new column name] varchar (20);

Questions : 32	Change column name and Make a unique column so we get no dupes.
Answer : 32	mysql> alter table [table name] change [old column name] [new column name] varchar (50); mysql> alter table [table name] add unique ([column name]);

Questions : 33	How to make a column bigger and Delete unique from table.
Answer : 33	mysql> alter table [table name] modify [column name] VARCHAR(3); mysql> alter table [table name] drop index [colmn name];

Questions : 34	How to Load a CSV file into a table
Answer : 34	mysql> LOAD DATA INFILE '/tmp/filename.csv' replace INTO TABLE [table name] FIELDS TERMINATED BY ',' LINES TERMINATED BY '\n' (field1,field2,field3);

Questions : 35	How to dump all databases for backup. Backup file is sql commands to recreate all db's.
Answer : 35	# [mysql dir]/bin/mysqldump -u root -ppassword --opt >/tmp/alldatabases.sql

Questions : 36	How to dump one database for backup.
Answer : 36	# [mysql dir]/bin/mysqldump -u username -ppassword --databases databasename >/tmp/databasename.sql

Questions : 37	How to dump a table from a database.
Answer : 37	# [mysql dir]/bin/mysqldump -c -u username -ppassword databasename tablename > /tmp/databasename.tablename.sql

Questions : 38	Restore database (or database table) from backup.
Answer : 38	# [mysql dir]/bin/mysql -u username -ppassword databasename < /tmp/databasename.sql

Questions : 39	How to Create Table show Example
Answer : 39	mysql> CREATE TABLE [table name] (firstname VARCHAR(20), middleinitial VARCHAR(3), lastname VARCHAR(35),suffix VARCHAR(3),officeid VARCHAR(10),userid VARCHAR(15),username VARCHAR(8),email VARCHAR(35),phone VARCHAR(25), groups VARCHAR(15),datestamp DATE,timestamp time,pgpemail VARCHAR(255));
Questions : 40	How to search second maximum(second highest) salary value(integer)from table employee (field salary)in the manner so that mysql gets less load?
Answers : 40	By below query we will get second maximum(second highest) salary value(integer)from table employee (field salary)in the manner so that mysql gets less load? SELECT DISTINCT(salary) FROM employee order by salary desc limit 1 , 1 ; (This way we will able to find out 3rd highest , 4th highest salary so on just need to change limit condtion like LIMIT 2,1 for 3rd highest and LIMIT 3,1 for 4th some one may finding this way useing below query that taken more time as compare to above query SELECT salary FROM employee where salary < (select max(salary) from employe) order by salary DESC limit 1 ;

Questions : 7

In how many ways we can retrieve the data in the result set of

MySQL using PHP? What is the difference between mysql_fetch_object and mysql_fetch_array ?

Answers : 7

we can retrieve the data in the result set of MySQL using PHP in 4 Ways

1. mysqli_fetch_row >> Get a result row as an enumerated array 2. mysqli_fetch_array >> Fetch a result row as associative and numeric array 3.mysqli_fetch_object >> Returns the current row of a result set as an object 4. mysqli_fetch_assoc >> Fetch a result row as an associative arraymysqli_fetch_object() is similar to mysqli_fetch_array(), with one difference -

an object is returned, instead of an array. Indirectly, that means that

we can only access the data by the field names, and not by their

offsets (numbers are illegal property names).

Questions : 8 How can we create a database using PHP and MySQL?

Answers : 8

We can create MySQL database with the use of

mysql_create_db("Database Name")

Questions : 9 What are the differences between require and include?

Answers : 9

Both include and require used to include a file but when included file not found

Include send Warning where as Require send Fatal Error .

Questions : 10 Can we use include ("xyz.PHP") two times in a PHP page "index.PHP"?

Answers : 10 Yes we can use include("xyz.php") more than one time in any page. but it create a prob when xyz.php file contain some funtions declaration then error will come for already declared function in this file else not a prob like if you want to show same content two time in page then must incude it two time not a prob

Questions : 11 What are the different tables(Engine) present in MySQL, which one is default?

Answers : 11

Following tables (Storage Engine) we can create

1. MyISAM(The default storage engine IN MYSQL Each MyISAM table is stored on disk in three files. The files have names that begin with the table name and have an extension to indicate the file type. An .frm file stores the table format. The data file has an .MYD (MYData) extension. The index file has an .MYI (MYIndex) extension. )

2. InnoDB(InnoDB is a transaction-safe (ACID compliant) storage engine for MySQL that has commit, rollback, and crash-recovery capabilities to protect user data.)

3. Merge

4. Heap (MEMORY)(The MEMORY storage engine creates tables with contents that are stored in memory. Formerly, these were known as HEAP tables. MEMORY is the preferred term, although HEAP remains supported for backward compatibility. )

5. BDB (BerkeleyDB)(Sleepycat Software has provided MySQL with the Berkeley DB transactional storage engine. This storage engine typically is called BDB for short. BDB tables may have a greater chance of surviving crashes and are also capable of COMMIT and ROLLBACK operations on transactions)

6. EXAMPLE

7. FEDERATED (It is a storage engine that accesses data in tables of remote databases rather than in local tables. )

8. ARCHIVE (The ARCHIVE storage engine is used for storing large amounts of data without indexes in a very small footprint. )

9. CSV (The CSV storage engine stores data in text files using comma-separated values format.)

10. BLACKHOLE (The BLACKHOLE storage engine acts as a "black hole" that accepts data but throws it away and does not store it. Retrievals always return an empty result)

Questions : 12 What are the differences between Get and post methods.

Answers : 12

There are some defference between GET and POST method
1. GET Method have some limit like only 2Kb data able to send for request
But in POST method unlimited data can we send
2. when we use GET method requested data show in url but
Not in POST method so POST method is good for send sensetive request

Questions : 13 How can I execute a PHP script using command line?

Answers : 13

Just run the PHP CLI (Command Line Interface) program and

provide the PHP script file name as the command line argument.

Questions : 14

Suppose your Zend engine supports the mode <? ?> Then how can u

configure your PHP Zend engine to support <?PHP ?> mode ?

Answers : 14

In php.ini file:

set

short_open_tag=on

to make PHP support

Questions : 15

Shopping cart online validation i.e. how can we configure Paypal,

etc.?

Answers : 15

Nothing more we have to do only redirect to the payPal url after

submit all information needed by paypal like amount,adresss etc.

Questions : 16 What is meant by nl2br()?

Answers : 16 Inserts HTML line breaks (<BR />) before all newlines in a string.

Questions : 17 What is htaccess? Why do we use this and Where?

Answers : 17

.htaccess files are configuration files of Apache Server which provide

a way to make configuration changes on a per-directory basis. A file,

containing one or more configuration directives, is placed in a particular

document directory, and the directives apply to that directory, and all

subdirectories thereof.

Questions : 18 How we get IP address of client, previous reference page etc ?

Answers : 18 By using $_SERVER['REMOTE_ADDR'],$_SERVER['HTTP_REFERER'] etc.

Questions : 19

What are the reasons for selecting lamp (Linux, apache, MySQL,

PHP) instead of combination of other software programs, servers and

operating systems?

Answers : 19

All of those are open source resource. Security of Linux is very

very more than windows. Apache is a better server that IIS both in

functionality and security. MySQL is world most popular open source

database. PHP is more faster that asp or any other scripting language.

Questions : 20

How can we encrypt and decrypt a data present in a MySQL table

using MySQL?

Answers : 20 AES_ENCRYPT () and AES_DECRYPT ()

Questions : 21 How can we encrypt the username and password using PHP?

Answers : 21

The functions in this section perform encryption and decryption, and

compression and uncompression:

encryption	decryption
AES_ENCRYT()	AES_DECRYPT()
ENCODE()	DECODE()
DES_ENCRYPT()	DES_DECRYPT()
ENCRYPT()	Not available
MD5()	Not available
OLD_PASSWORD()	Not available
PASSWORD()	Not available
SHA() or SHA1()	Not available
Not available	UNCOMPRESSED_LENGTH()

Questions : 22

What are the features and advantages of object-oriented

programming?

Answers : 22

One of the main advantages of OO programming is its ease of

modification; objects can easily be modified and added to a system there

by reducing maintenance costs. OO programming is also considered to be

better at modeling the real world than is procedural programming. It

allows for more complicated and flexible interactions. OO systems are

also easier for non-technical personnel to understand and easier for

them to participate in the maintenance and enhancement of a system

because it appeals to natural human cognition patterns.

For some systems, an OO approach can speed development time since many

objects are standard across systems and can be reused. Components that

manage dates, shipping, shopping carts, etc. can be purchased and easily

modified for a specific system

Questions : 23

What are the differences between procedure-oriented languages and

object-oriented languages?

Answers : 23

There are lot of difference between procedure language and object oriented like below

1>Procedure language easy for new developer but complex to understand whole software as compare to object oriented model

2>In Procedure language it is difficult to use design pattern mvc , Singleton pattern etc but in OOP you we able to develop design pattern

3>IN OOP language we able to ree use code like Inheritance ,polymorphism etc but this type of thing not available in procedure language on that our Fonda use COPY and PASTE .

Questions : 24 What is the use of friend function?

Answers : 24

Sometimes a function is best shared among a number of different

classes. Such functions can be declared either as member functions of

one class or as global functions. In either case they can be set to be

friends of other classes, by using a friend specifier in the class that

is admitting them. Such functions can use all attributes of the class

which names them as a friend, as if they were themselves members of that

class.

A friend declaration is essentially a prototype for a member function,

but instead of requiring an implementation with the name of that class

attached by the double colon syntax, a global function or member

function of another class provides the match.

Questions : 25

What are the differences between public, private, protected,

static, transient, final and volatile?

Answer : 25

Public: Public declared items can be accessed everywhere.

Protected: Protected limits access to inherited and parent

classes (and to the class that defines the item).

Private: Private limits visibility only to the class that defines

the item.

Static: A static variable exists only in a local function scope,

but it does not lose its value when program execution leaves this scope.

Final: Final keyword prevents child classes from overriding a

method by prefixing the definition with final. If the class itself is

being defined final then it cannot be extended.

transient: A transient variable is a variable that may not

be serialized.

volatile: a variable that might be concurrently modified by multiple

threads should be declared volatile. Variables declared to be volatile

will not be optimized by the compiler because their value can change at

any time.

Questions : 26 What are the different types of errors in PHP?

Answer : 26

Three are three types of errors:1. Notices: These are trivial,

non-critical errors that PHP encounters while executing a script â€“ for

example, accessing a variable that has not yet been defined. By default,

such errors are not displayed to the user at all â€“ although, as you will

see, you can change this default behavior.2. Warnings: These are more serious errors â€“ for example, attempting

to include() a file which does not exist. By default, these errors are

displayed to the user, but they do not result in script termination.3. Fatal errors: These are critical errors â€“ for example,

instantiating an object of a non-existent class, or calling a

non-existent function. These errors cause the immediate termination of

the script, and PHP's default behavior is to display them to the user

when they take place.

Questions : 27 What is the functionality of the function strstr and stristr?

Answers : 27

strstr Returns part of string from the first occurrence of needle(sub string that we finding out ) to the end of string.

$email= 'sonialouder@gmail.com';

$domain = strstr($email, '@');

echo $domain; // prints @gmail.com

here @ is the needle

stristr is case-insensitive means able not able to diffrenciate between a and A

Questions : 28 How can we submit a form without a submit button?

Answer : 28

Java script submit() function is used for submit form without submit button

on click call document.formname.submit()

Questions : 29 How can we convert asp pages to PHP pages?

Answer : 29

there are lots of tools available for asp to PHP conversion. you can

search Google for that. the best one is available athttp://asp2php.naken.cc./

Questions : 30 What is the functionality of the function htmlentities?

Answer : 30

Convert all applicable characters to HTML entities

This function is identical to htmlspecialchars() in all ways, except

with htmlentities(), all characters which have HTML character entity

equivalents are translated into these entities.

Questions : 31 How can we get second of the current time using date function?

Answer : 31 $second = date("s");

Questions : 32 How can we convert the time zones using PHP?

Answer : 32

For convert the time zones using PHP we have to first set time zone

By using PHP function date_default_timezone_set()

If we want to set time zone of 'Europe/London' we have to call this funtion as

date_default_timezone_set('Europe/London')

so Now generate the timestamp for that particular timezone, on Sept 1st, 2012 at 8 am

$pcds = mktime(8, 0, 0, 9, 1, 2012);

Now set the other timezone like US/Eastern

date_default_timezone_set('US/Eastern');

date(DATE_RFC1123, $pcds) date(DATE_RFC1123, $pcds)

Output the date in a standard format (RFC1123)

Questions : 33 What is meant by urlencode and urldocode?

Answer : 33

URLencode returns a string in which all non-alphanumeric characters

except -_. have been replaced with a percent (%)

sign followed by two hex digits and spaces encoded as plus (+)

signs. It is encoded the same way that the posted data from a WWW form

is encoded, that is the same way as in

application/x-www-form-urlencoded media type.

urldecode decodes any %##

encoding in the given string.

Questions : 34 What is the difference between the functions unlink and unset?

Answer : 34

unlink() deletes the given file from the file system.

unset() makes a variable undefined.

Questions : 35 How can we register the variables into a session?

Answer : 35 $_SESSION['name'] = "sonia";

Questions : 36

How can we get the properties (size, type, width, height) of an

image using PHP image functions?

Answer : 36

To know the Image type use exif_imagetype () function

To know the Image size use getimagesize () function

To know the image width use imagesx () function

To know the image height use imagesy() function t

Questions : 37 How can we get the browser properties using PHP?

Answer : 37

By using

$_SERVER['HTTP_USER_AGENT']

variable.

Questions : 38

What is the maximum size of a file that can be uploaded using PHP

and how can we change this?

Answer : 38

By default the maximum size is 2MB. and we can change the following

setup at php.iniupload_max_filesize = 2M

Questions : 39 How can we increase the execution time of a PHP script?

Answer : 39

by changing the following setup at php.inimax_execution_time = 30

; Maximum execution time of each script, in seconds

Questions : 40

How can we take a backup of a MySQL table and how can we restore

it. ?

Answer : 40

To backup: BACKUP TABLE tbl_name[,tbl_nameâ€¦] TO

'/path/to/backup/directory'

RESTORE TABLE tbl_name[,tbl_nameâ€¦] FROM '/path/to/backup/directory'mysqldump: Dumping Table Structure and DataUtility to dump a database or a collection of database for backup or

for transferring the data to another SQL server (not necessarily a MySQL

server). The dump will contain SQL statements to create the table and/or

populate the table.

-t, â€“no-create-info

Don't write table creation information (the CREATE TABLE statement).

-d, â€“no-data

Don't write any row information for the table. This is very useful if

you just want to get a dump of the structure for a table!

Questions : 41

How can we optimize or increase the speed of a MySQL select

query?

Answer : 41

first of all instead of using select * from table1, use select

column1, column2, column3.. from table1
Look for the opportunity to introduce index in the table you are

querying.
use limit keyword if you are looking for any specific number of

rows from the result set.

Questions : 42 How many ways can we get the value of current session id?

Answer : 42 session_id() returns the session id for the current session.

Questions : 43

How can we destroy the session, how can we unset the variable of

a session?

Answer : 43

session_unregister â€” Unregister a global variable from the current

session

session_unset â€” Free all session variables

Questions : 44 How can we set and destroy the cookie n php?

Answer : 44

By using setcookie(name, value, expire, path, domain); function we can set the cookie in php ;

Set the cookies in past for destroy. like

setcookie("user", "sonia", time()+3600); for set the cookie

setcookie("user", "", time()-3600); for destroy or delete the cookies;

Questions : 45

How many ways we can pass the variable through the navigation

between the pages?

Answer : 45

GET/QueryString
POST

Questions : 46 What is the difference between ereg_replace() and eregi_replace()?

Answer : 46

eregi_replace() function is identical to ereg_replace() except that

this ignores case distinction when matching alphabetic

characters.eregi_replace() function is identical to ereg_replace()

except that this ignores case distinction when matching alphabetic

characters.

Questions : 47 What are the different functions in sorting an array?

Answer : 47

Sort(), arsort(),

asort(), ksort(),

natsort(), natcasesort(),

rsort(), usort(),

array_multisort(), and

uksort().

Questions : 48 How can we know the count/number of elements of an array?

Answer : 48

2 ways

a) sizeof($urarray) This function is an alias of count()

b) count($urarray)

Questions : 49 what is session_set_save_handler in PHP?

Answer : 49 session_set_save_handler() sets the user-level session storage functions which are used for storing and retrieving data associated with a session. This is most useful when a storage method other than those supplied by PHP sessions is preferred. i.e. Storing the session data in a local database.

Questions : 50

How can I know that a variable is a number or not using a

JavaScript?

Answer : 50

bool is_numeric ( mixed var)

Returns TRUE if var is a number or a numeric string, FALSE otherwise.or use isNaN(mixed var)The isNaN() function is used to check if a value is not a number.

Questions : 51

List out some tools through which we can draw E-R diagrams for

mysql.

Answer : 51

Case Studio

Smart Draw

Questions : 52

How can I retrieve values from one database server and store them

in other database server using PHP?

Answer : 52

we can always fetch from one database and rewrite to another. here

is a nice solution of it.$db1 = mysql_connect("host","user","pwd")

mysql_select_db("db1", $db1);

$res1 = mysql_query("query",$db1);$db2 = mysql_connect("host","user","pwd")

mysql_select_db("db2", $db2);

$res2 = mysql_query("query",$db2);At this point you can only fetch records from you previous ResultSet,

i.e $res1 â€“ But you cannot execute new query in $db1, even if you

supply the link as because the link was overwritten by the new db.so at this point the following script will fail

$res3 = mysql_query("query",$db1); //this will failSo how to solve that?

take a look below.

$db1 = mysql_connect("host","user","pwd")

mysql_select_db("db1", $db1);

$res1 = mysql_query("query",$db1);

$db2 = mysql_connect("host","user","pwd", true)

mysql_select_db("db2", $db2);

$res2 = mysql_query("query",$db2);

So mysql_connect has another optional boolean parameter which

indicates whether a link will be created or not. as we connect to the

$db2 with this optional parameter set to 'true', so both link will

remain live.

now the following query will execute successfully.

$res3 = mysql_query("query",$db1);

Questions : 53 List out the predefined classes in PHP?

Answer : 53

Directory

stdClass

__PHP_Incomplete_Class

exception

php_user_filter

Questions : 54

How can I make a script that can be bi-language (supports

English, German)?

Answer : 54

You can maintain two separate language file for each of the

language. all the labels are putted in both language files as variables

and assign those variables in the PHP source. on runtime choose the

required language option.

Questions : 55 What are the difference between abstract class and interface?

Answer : 55

Abstract class: abstract classes are the class where one or more

methods are abstract but not necessarily all method has to be abstract.

Abstract methods are the methods, which are declare in its class but not

define. The definition of those methods must be in its extending class.Interface: Interfaces are one type of class where all the methods are

abstract. That means all the methods only declared but not defined. All

the methods must be define by its implemented class.

Questions : 56 How can we send mail using JavaScript?

Answer : 56

JavaScript does not have any networking capabilities as it is

designed to work on client site. As a result we can not send mails using

JavaScript. But we can call the client side mail protocol mailto

via JavaScript to prompt for an email to send. this requires the client

to approve it.

Questions : 57 How can we repair a MySQL table?

Answer : 57

The syntex for repairing a MySQL table is

REPAIR TABLENAME, [TABLENAME, ], [Quick],[Extended]

This command will repair the table specified if the quick is given the

MySQL will do a repair of only the index tree if the extended is given

it will create index row by row

Questions : 58 What are the advantages of stored procedures, triggers, indexes?

Answer : 58

A stored procedure is a set of SQL commands that can be compiled and

stored in the server. Once this has been done, clients don't need to

keep re-issuing the entire query but can refer to the stored procedure.

This provides better overall performance because the query has to be

parsed only once, and less information needs to be sent between the

server and the client. You can also raise the conceptual level by having

libraries of functions in the server. However, stored procedures of

course do increase the load on the database server system, as more of

the work is done on the server side and less on the client (application)

side.Triggers will also be implemented. A trigger is effectively a type of

stored procedure, one that is invoked when a particular event occurs.

For example, you can install a stored procedure that is triggered each

time a record is deleted from a transaction table and that stored

procedure automatically deletes the corresponding customer from a

customer table when all his transactions are deleted.Indexes are used to find rows with specific column values quickly.

Without an index, MySQL must begin with the first row and then read

through the entire table to find the relevant rows. The larger the

table, the more this costs. If the table has an index for the columns in

question, MySQL can quickly determine the position to seek to in the

middle of the data file without having to look at all the data. If a

table has 1,000 rows, this is at least 100 times faster than reading

sequentially. If you need to access most of the rows, it is faster to

read sequentially, because this minimizes disk seeks.

Questions : 59

What is the maximum length of a table name, database name, and

fieldname in MySQL?

Answer : 59

The following table describes the maximum length for each type of

identifier.

Identifier	Maximum Length (bytes)
Database	64
Table	64
Column	64
Index	64
Alias	255

There are some restrictions on the characters that may appear in

identifiers:

Questions : 60 How many values can the SET function of MySQL take?

Answer : 60

MySQL set can take zero or more values but at the maximum it can

take 64 values

Questions : 61

What are the other commands to know the structure of table using

MySQL commands except explain command?

Answer : 61 describe Table-Name;

Questions : 62 How many tables will create when we create table, what are they?

Answer : 62

The '.frm' file stores the table definition.

The data file has a '.MYD' (MYData) extension.

The index file has a '.MYI' (MYIndex) extension,

Questions : 63

What is the purpose of the following files having extensions 1) .frm

2) .myd 3) .myi? What do these files contain?

Answer : 63

In MySql, the default table type is MyISAM.

Each MyISAM table is stored on disk in three files. The files have names

that begin with the table name and have an extension to indicate the

file type.

The '.frm' file stores the table definition.

The data file has a '.MYD' (MYData) extension.

The index file has a '.MYI' (MYIndex) extension,

Questions : 64 What is maximum size of a database in MySQL?

Answer : 64

If the operating system or filesystem places a limit on the number

of files in a directory, MySQL is bound by that constraint.The efficiency of the operating system in handling large numbers of

files in a directory can place a practical limit on the number of tables

in a database. If the time required to open a file in the directory

increases significantly as the number of files increases, database

performance can be adversely affected.

The amount of available disk space limits the number of tables.

MySQL 3.22 had a 4GB (4 gigabyte) limit on table size. With the MyISAM

storage engine in MySQL 3.23, the maximum table size was increased to

65536 terabytes (2567 â€“ 1 bytes). With this larger allowed table size,

the maximum effective table size for MySQL databases is usually

determined by operating system constraints on file sizes, not by MySQL

internal limits.The InnoDB storage engine maintains InnoDB tables within a tablespace

that can be created from several files. This allows a table to exceed

the maximum individual file size. The tablespace can include raw disk

partitions, which allows extremely large tables. The maximum tablespace

size is 64TB.

The following table lists some examples of operating system file-size

limits. This is only a rough guide and is not intended to be definitive.

For the most up-to-date information, be sure to check the documentation

specific to your operating system.

Operating System File-size LimitLinux 2.2-Intel 32-bit 2GB (LFS: 4GB)

Linux 2.4+ (using ext3 filesystem) 4TB

Solaris 9/10 16TB

NetWare w/NSS filesystem 8TB

Win32 w/ FAT/FAT32 2GB/4GB

Win32 w/ NTFS 2TB (possibly larger)

MacOS X w/ HFS+ 2TB

Questions : 65 Give the syntax of Grant and Revoke commands?

Answer : 65

The generic syntax for grant is as following

> GRANT [rights] on [database/s] TO [username@hostname] IDENTIFIED BY

[password]

now rights can be

a) All privileges

b) combination of create, drop, select, insert, update and delete etc.We can grant rights on all databse by using *.* or some specific

database by database.* or a specific table by database.table_name

username@hotsname can be either username@localhost, username@hostname

and username@%

where hostname is any valid hostname and % represents any name, the *.*

any condition

password is simply the password of userThe generic syntax for revoke is as following

> REVOKE [rights] on [database/s] FROM [username@hostname]

now rights can be as explained above

a) All privileges

b) combination of create, drop, select, insert, update and delete etc.

username@hotsname can be either username@localhost, username@hostname

and username@%

where hostname is any valid hostname and % represents any name, the *.*

any condition

Questions : 66 Explain Normalization concept?

Answer : 66

The normalization process involves getting our data to conform to

three progressive normal forms, and a higher level of normalization

cannot be achieved until the previous levels have been achieved (there

are actually five normal forms, but the last two are mainly academic and

will not be discussed).First Normal FormThe First Normal Form (or 1NF) involves removal of redundant data

from horizontal rows. We want to ensure that there is no duplication of

data in a given row, and that every column stores the least amount of

information possible (making the field atomic).Second Normal FormWhere the First Normal Form deals with redundancy of data across a

horizontal row, Second Normal Form (or 2NF) deals with redundancy of

data in vertical columns. As stated earlier, the normal forms are

progressive, so to achieve Second Normal Form, your tables must already

be in First Normal Form.Third Normal Form

I have a confession to make; I do not often use Third Normal Form. In

Third Normal Form we are looking for data in our tables that is not

fully dependant on the primary key, but dependant on another value in

the table

Questions : 67 How can we find the number of rows in a table using MySQL?

Answer : 67

Use this for mysql

>SELECT COUNT(*) FROM table_name;

Questions : 68 How can we find the number of rows in a result set using PHP?

Answer : 68

$result = mysql_query($sql, $db_link);

$num_rows = mysql_num_rows($result);

echo "$num_rows rows found";

Questions : 69 How many ways we can we find the current date using MySQL?

Answer : 69

SELECT CURDATE();

CURRENT_DATE() = CURDATE()

for time use

SELECT CURTIME();

CURRENT_TIME() = CURTIME()

Questions : 70

What are the advantages and disadvantages of Cascading Style

Sheets?

Answer : 70

External Style SheetsAdvantagesCan control styles for multiple documents at once. Classes can be

created for use on multiple HTML element types in many documents.

Selector and grouping methods can be used to apply styles under complex

contextsDisadvantagesAn extra download is required to import style information for each

document The rendering of the document may be delayed until the external

style sheet is loaded Becomes slightly unwieldy for small quantities of

style definitionsEmbedded Style Sheets

Advantages

Classes can be created for use on multiple tag types in the document.

Selector and grouping methods can be used to apply styles under complex

contexts. No additional downloads necessary to receive style information

Disadvantages

This method can not control styles for multiple documents at once

Inline Styles

Advantages

Useful for small quantities of style definitions. Can override other

style specification methods at the local level so only exceptions need

to be listed in conjunction with other style methods

Disadvantages

Does not distance style information from content (a main goal of

SGML/HTML). Can not control styles for multiple documents at once.

Author can not create or control classes of elements to control multiple

element types within the document. Selector grouping methods can not be

used to create complex element addressing scenarios

Questions : 71 What type of inheritance that PHP supports?

Answer : 71

In PHP an extended class is always dependent on a single base class,

that is, multiple inheritance is not supported. Classes are extended

using the keyword 'extends'.

Questions : 72

What is the difference between Primary Key and

Unique key?

Answer : 72

Primary Key: A column in a table whose values uniquely identify the

rows in the table. A primary key value cannot be NULL.

Unique Key: Unique Keys are used to uniquely identify each row in the

table. There can be one and only one row for each unique key value. So

NULL can be a unique key.There can be only one primary key for a table but there can be more

than one unique for a table.

Question : 73

what is garbage collection? default time ? refresh time?

Answer : 73 Garbage Collection is an automated part of PHP , If the Garbage Collection process runs, it then analyzes any files in the /tmp for any session files that have not been accessed in a certain amount of time and physically deletes them. Garbage Collection process only runs in the default session save directory, which is /tmp. If you opt to save your sessions in a different directory, the Garbage Collection process will ignore it. the Garbage Collection process does not differentiate between which sessions belong to whom when run. This is especially important note on shared web servers. If the process is run, it deletes ALL files that have not been accessed in the directory. There are 3 PHP.ini variables, which deal with the garbage collector: PHP ini value name default session.gc_maxlifetime 1440 seconds or 24 minutes session.gc_probability 1 session.gc_divisor 100

Questions : 74 What are the advantages/disadvantages of MySQL and PHP?

Answer : 74

Both of them are open source software (so free of cost), support

cross platform. php is faster then ASP and JSP.

Questions : 75 What is the difference between GROUP BY and ORDER BY in Sql?

Answer : 75

ORDER BY [col1],[col2],â€¦,[coln]; Tels DBMS according to what columns

it should sort the result. If two rows will hawe the same value in col1

it will try to sort them according to col2 and so on.GROUP BY

[col1],[col2],â€¦,[coln]; Tels DBMS to group results with same value of

column col1. You can use COUNT(col1), SUM(col1), AVG(col1) with it, if

you want to count all items in group, sum all values or view average

Questions : 76 What is the difference between char and varchar data types?

Answer : 76

Set char to occupy n bytes and it will take n bytes even if u r

storing a value of n-m bytes

Set varchar to occupy n bytes and it will take only the required space

and will not use the n bytes

eg. name char(15) will waste 10 bytes if we store 'romharshan', if each char

takes a byte

eg. name varchar(15) will just use 5 bytes if we store 'romharshan', if each

char takes a byte. rest 10 bytes will be free.

Questions : 77 What is the functionality of md5 function in PHP?

Answer : 77

Calculate the md5 hash of a string. The hash is a 32-character

hexadecimal number. I use it to generate keys which I use to identify

users etc. If I add random no techniques to it the md5 generated now

will be totally different for the same string I am using.

Questions : 78 How can I load data from a text file into a table?

Answer : 78

you can use LOAD DATA INFILE file_name; syntax to load data

from a text file. but you have to make sure thata) data is delimited

b) columns and data matched correctly

Questions : 79

How can we know the number of days between two given dates using

MySQL?

Answer : 79 SELECT DATEDIFF("2007-03-07","2005-01-01");

Questions : 80 How can we know the number of days between two given dates using PHP?

Answer : 80

$date1 = date("Y-m-d");

$date2 = "2006-08-15";

$days = (strtotime($date1) - strtotime($date2)) / (60 * 60 * 24);

Questions : 81 How we load all classes that placed in different directory in one PHP File , means how to do auto load classes

Answer : 81

by using spl_autoload_register('autoloader::funtion');

Like below

class autoloader

{

public static function moduleautoloader($class)

{

$path = $_SERVER['DOCUMENT_ROOT'] . "/modules/{$class}.php";

if (is_readable($path)) require $path;

}

public static function daoautoloader($class)

{

$path = $_SERVER['DOCUMENT_ROOT'] . "/dataobjects/{$class}.php";

if (is_readable($path)) require $path;

}

public static function includesautoloader($class)

{

$path = $_SERVER['DOCUMENT_ROOT'] . "/includes/{$class}.php";

if (is_readable($path)) require $path;

}

spl_autoload_register('autoloader::includesautoloader');

spl_autoload_register('autoloader::daoautoloader');

spl_autoload_register('autoloader::moduleautoloader');

Questions : 82 How many types of Inheritances used in PHP and how we achieve it

Answer : 82

As far PHP concern it only support single Inheritance in scripting.

we can also use interface to achieve multiple inheritance.

Questions : 83 PHP how to know user has read the email?

Answers : 83

Using Disposition-Notification-To: in mailheader we can get read receipt.

Add the possibility to define a read receipt when sending an email.

Itâ€™s quite straightforward, just edit email.php, and add this at vars definitions:

var $readReceipt = null;

And then, at â€˜createHeaderâ€™ function add:

if (!empty($this->readReceipt)) {

$this->__header .= â€˜Disposition-Notification-To: â€˜ . $this->__formatAddress($this->readReceipt) . $this->_newLine;

}

Questions : 84 What are default session time and path?

Answers : 84

default session time in PHP is 1440 seconds or 24 minutes

Default session save path id temporary folder /tmp

Questions : 85 how to track user logged out or not? when user is idle ?

Answers : 85 By checking the session variable exist or not while loading th page. As the session will exist longer as till browser closes. The default behaviour for sessions is to keep a session open indefinitely and only to expire a session when the browser is closed. This behaviour can be changed in the php.ini file by altering the line session.cookie_lifetime = 0 to a value in seconds. If you wanted the session to finish in 5 minutes you would set this to session.cookie_lifetime = 300 and restart your httpd server.

Questions : 86 how to track no of user logged in ?

Answers : 86 whenever a user logs in track the IP, userID etc..and store it in a DB with a active flag while log out or sesion expire make it inactive. At any time by counting the no: of active records we can get the no: of visitors.

Questions : 87 in PHP for pdf which library used?

Answers : 87 The PDF functions in PHP can create PDF files using the PDFlib library With version 6, PDFlib offers an object-oriented API for PHP 5 in addition to the function-oriented API for PHP 4. There is also the Â» Panda module. FPDF is a PHP class which allows to generate PDF files with pure PHP, that is to say without using the PDFlib library. F from FPDF stands for Free: you may use it for any kind of usage and modify it to suit your needs. FPDF requires no extension (except zlib to activate compression and GD for GIF support) and works with PHP4 and PHP5.

Questions : 88 for image work which library?

Answers : 88 we will need to compile PHP with the GD library of image functions for this to work. GD and PHP may also require other libraries, depending on which image formats you want to work with.

Questions : 89 what is design pattern? explain all including singleton pattern?

Answers : 89

A design pattern is a general reusable solution to a commonly occurring problem in software design.

The Singleton design pattern allows many parts of a program to share a single resource without having to work out the details of the sharing themselves.

Answer in Details

Questions : 90 what are magic methods?

Answers : 90 Magic methods are the members functions that is available to all the instance of class Magic methods always starts with "__". Eg. __construct All magic methods needs to be declared as public To use magic method they should be defined within the class or program scope Various Magic Methods used in PHP 5 are: __construct() __destruct() __set() __get() __call() __toString() __sleep() __wakeup() __isset() __unset() __autoload() __clone()

Questions : 91 what is magic quotes?

Answers : 91 Magic Quotes is a process that automagically escapes ncoming data to the PHP script. Itâ€™s preferred to code with magic quotes off and to instead escape the data at runtime, as needed. This feature has been DEPRECATED as of PHP 5.3.0 and REMOVED as of PHP 6.0.0. Relying on this feature is highly discouraged.

Questions : 92 what is cross site scripting? SQL injection?

Answers : 92 Cross-site scripting (XSS) is a type of computer security vulnerability typically found in web applications which allow code injection by malicious web users into the web pages viewed by other users. Examples of such code include HTML code and client-side scripts. SQL injection is a code injection technique that exploits a security vulnerability occurring in the database layer of an application. The vulnerability is present when user input is either incorrectly filtered for string literal escape characters embedded in SQL statements or user input is not strongly typed and thereby unexpectedly executed

Questions : 93 what is URL rewriting?

Answers : 93 Using URL rewriting we can convert dynamic URl to static URL Static URLs are known to be better than Dynamic URLs because of a number of reasons 1. Static URLs typically Rank better in Search Engines. 2. Search Engines are known to index the content of dynamic pages a lot slower compared to static pages. 3. Static URLs are always more friendlier looking to the End Users. along with this we can use URL rewriting in adding variables [cookies] to the URL to handle the sessions.

Questions : 94 what is the major php security hole? how to avoid?

Answers : 94

1. Never include, require, or otherwise open a file with a filename based on user input, without thoroughly checking it first.

2. Be careful with eval() Placing user-inputted values into the eval() function can be extremely dangerous. You essentially give the malicious user the ability to execute any command he or she wishes!

3. Be careful when using register_globals = ON It was originally designed to make programming in PHP easier (and that it did), but misuse of it often led to security holes

4. Never run unescaped queries

5. For protected areas, use sessions or validate the login every time.

6. If you donâ€™t want the file contents to be seen, give the file a .php extension.

Questions : 95 whether PHP supports Microsoft SQL server ?

Answers : 95 The SQL Server Driver for PHP v1.0 is designed to enable reliable, scalable integration with SQL Server for PHP applications deployed on the Windows platform. The Driver for PHP is a PHP 5 extension that allows the reading and writing of SQL Server data from within PHP scripts. using MSSQL or ODBC modules we can access Microsoft SQL server.

Questions : 96 what is MVC? why its been used?

Answers : 96

Model-view-controller (MVC) is an architectural pattern used in software engineering. Successful use of the pattern isolates business logic from user interface considerations, resulting in an application where it is easier to modify either the visual appearance of the application or the underlying business rules without affecting the other. In MVC, the model represents the information (the data) of the application; the view corresponds to elements of the user interface such as text, checkbox items, and so forth; and the controller manages the communication of data and the business rules used to manipulate the data to and from the model. WHY ITS NEEDED IS 1 Modular separation of function 2 Easier to maintain 3 View-Controller separation means:

A â€” Tweaking design (HTML) without altering code B â€” Web design staff can modify UI without understanding code

Questions : 97 what is framework? how it works? what is advantage?

Answers : 97 In general, a framework is a real or conceptual structure intended to serve as a support or guide for the building of something that expands the structure into something useful. Advantages : Consistent Programming Model Direct Support for Security Simplified Development Efforts Easy Application Deployment and Maintenance

Questions : 98 what is CURL?

Answers : 98

CURL means Client URL Library

curl is a command line tool for transferring files with URL syntax, supporting FTP, FTPS, HTTP, HTTPS, SCP, SFTP, TFTP, TELNET, DICT, LDAP, LDAPS and FILE. curl supports SSL certificates, HTTP POST, HTTP PUT, FTP uploading, HTTP form based upload, proxies, cookies, user+password authentication (Basic, Digest, NTLM, Negotiate, kerberosâ€¦), file transfer resume, proxy tunneling and a busload of other useful tricks.

CURL allows you to connect and communicate to many different types of servers with many different types of protocols. libcurl currently supports the http, https, ftp, gopher, telnet, dict, file, and ldap protocols. libcurl also supports HTTPS certificates, HTTP POST, HTTP PUT, FTP uploading (this can also be done with PHPâ€™s ftp extension), HTTP form based upload, proxies, cookies, and user+password authentication.

Questions : 99 what is PDO ?

Answers : 99

The PDO ( PHP Data Objects ) extension defines a lightweight, consistent interface for accessing databases in PHP. if you are using the PDO API, you could switch the database server you used, from say PgSQL to MySQL, and only need to make minor changes to your PHP code.

While PDO has its advantages, such as a clean, simple, portable API but its maindisadvantage is that it doesn't allow you to use all of the advanced features that are available in the latest versions of MySQL server. For example, PDO does not allow you to use MySQL's support for Multiple Statements.

Just need to use below code for connect mysql using PDO

try {

$dbh = new PDO("mysql:host=$hostname;dbname=databasename", $username, $password);

$sql = "SELECT * FROM employee";

foreach ($dbh->query($sql) as $row)

{

print $row['employee_name'] .' - '. $row['employee_age'] ;

}

catch(PDOException $e)

{

echo $e->getMessage();

}

Questions : 100 What is PHP's mysqli Extension?

Answers : 100

The mysqli extension, or as it is sometimes known, the MySQL improved extension, was developed to take advantage of new features found in MySQL systems versions 4.1.3 and newer. The mysqli extension is included with PHP versions 5 and later.

The mysqli extension has a number of benefits, the key enhancements over the mysql extension being:

=>Object-oriented interface

=>Support for Prepared Statements

=>Support for Multiple Statements

=>Support for Transactions

=>Enhanced debugging capabilities

=>Embedded server support

Hema

Wednesday, 18 February 2015

PHP Interview Questions and Answers

Top Regular Expressions interview questions and answers

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