41. What are
the other commands to know the structure of table using mysql commandsexcept
explain command?
Answer:describe
table_name;
42. How many
tables will create when we create table, what are they?
Answer:3 tables
will create when we create table. They areThe `.frm' file stores the table
definition.The data file has a `.MYD' (MYData) extension.The index file has
a `.MYI' (MYIndex) extension,
43. What is the
purpose of the following files having extensions 1) frm 2) MYD 3) MYI.What
these files contains?
Answer:In
MySql, the default table type is MyISAM.Each MyISAM table is stored
on disk in three files. The files have names that beginwith 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,
44. How can we
find the number of rows in a table using mysql?
Answer:Use this
for mysql>SELECT COUNT(*) FROM table_name;but if u r particular about no of
rows with some special resultdo this>SELECT [colms],COUNT(*) FROM table_name
[where u put conditions];
45. How can we
find the number of rows in a result set using php?
Answer:for
PHP$result = mysql_query($any_valid_sql, $database_link);$num_rows =
mysql_num_rows($result);echo “$num_rows rows found”;
46. How many
ways we can we find the current date using mysql?
Answer:SELECT
CURDATE();CURRENT_DATE() = CURDATE()for time useSELECT CURTIME();CURRENT_TIME()
= CURTIME()
47. What type
of inheritance that php supports?
Answer:In PHP
an extended class is always dependent on a single base class, that is,
multipleinheritance is not supported. Classes are extended using the keyword
'extends'.Usage:
var$owner;functionset_owner($name) { $this->owner=$name;}}?>
48. What are
the advantages/disadvantages of mysql and php?
Answer:Both of
them are open source software (so free of cost), support cross
platform.php is faster then ASP and JSP.
49. How can I
load data from a text file into a table?
Answer:The
mysql provides a LOAD DATA INFILE syntax. U can load data from
a file.Gr8 tool but u need to make sure thata) data is delimitedb) u match
the colms and data correctly
dont use w/out
first learning the syntax
50. How can we
know the number of days between two given dates using mysql?
Answer:select
DIFFDATE( NOW(), ‘yyyy-mm-dd’ );
51. How can we
change the name of a column of a table?
Answer:
MySQL query to rename table: RENAME TABLE
tbl_name
TO
new_tbl_name
[,
tbl_name2
TO
new_tbl_name2
] ...or,
ALTER TABLE
tableName CHANGE OldName newName.
52. How can we
change the name and data type of a column of a table?
Answer: ALTER [IGNORE] TABLE
tbl_name
alter_specification
[,
alter_specification
] | CHANGE [COLUMN]
old_col_name
column_definition
[FIRST|AFTER
col_name
]
53. What are
the differences between drop a table and truncate a table?
Answer:Delete a
Table or DatabaseTo delete a table (the table structure, attributes, andindexes
will also be deleted).What if we only want to get rid of the data inside
a table, and not the table itself?Use the TRUNCATE TABLE command
(deletes only the data inside the table).
54. What is
meant by MIME?
Answer:Multipurpose
Internet Mail Extensions.WWW's ability to recognise and handle files of
different types is largely dependenton the use of the MIME (Multipurpose
Internet Mail Extensions) standard. Thestandard provides for a system of
registration of file types with information aboutthe applications needed to
process them. This information is incorporated into Webserver and browser
software, and enables the automatic recognition and display of registered
file types.
55. What is
meant by PEAR in php?
Answer:PEAR is
short for “PHP Extension and Application Repository” and is
pronounced just like the fruit. The purpose of PEAR is to provide:A
structured library of open-sourced code for PHP usersA system for code
distribution and package maintenanceA standard style for code written in PHPThe
PHP Foundation Classes (PFC),The PHP Extension Community Library (PECL),A web
site, mailing lists and download mirrors to support the PHP/PEARcommunityPEAR
is a community-driven project with the PEAR Group as the governing body.The
project has been founded by Stig S. Bakken in 1999 and quite a lot of
peoplehave joined the project since
then.http://pear.php.net/manual/en/introduction.php
56. How
can I load the dll’s dynamically?98. How many ways we can give the output to
a browser?
Answer:HTML
outputPHP, ASP, JSP, Servlet FunctionScript Language output FunctionDifferent
Type of embedded Package to output to a browser
57. How can we
know that a session is started or not?
Answer:a
session starts by session_start()function.this session_start() is always
declared in header portion.it always declares first.thenwe write
session_register().
58. What is the
default session time in php and how can I change it?
Answer:The
default session time in php is until closing of browser
59. What
changes I have to done in php.ini file for file uploading?
Answer:Make the
following Line uncomment like:; Whether to allow HTTP file uploads.file_uploads
= On; Temporary directory for HTTP uploaded files (will use system default if
not; specified).upload_tmp_dir = C:\apache2triad\temp; Maximum allowed size for
uploaded files.upload_max_filesize = 2M
60. What are
the differences between mysql_fetch_array(), mysql_fetch_object(),mysql_fetch_row()?
Answer:mysql_fetch_array--
Fetch a result row as an associative array, a numeric array,
orboth.mysql_fetch_object( resource result )Returns an object with properties
that correspond to the fetched row and moves theinternal data pointer ahead.
Returns an object with properties that correspond tothe fetched row, or FALSE
if there are no more rowsmysql_fetch_row()fetches one row of data from the
result associated with thespecified result identifier. The row is returned as
an array. Each result column isstored in an array offset, starting at
offset 0.
61. Steps for
the payment gateway processing?
Ans:An online
payment gateway is the interface between your merchant account andyour Web
site. The online payment gateway allows you to immediately verify creditcard
transactions and authorize funds on a customer's credit card directly fromyour
Web site. It then passes the transaction off to your merchant bank
forprocessing, commonly referred to as transaction batching
62. List out
different arguments in php header function?
Answer:
void
header
( string string
[, bool replace [, int http_response_code]])
63. What is the
difference between and And which can bepreferable?
Answer:If
functionality is same but
64. What are
the differences between php3 and php4 versions?
Answer:As has
already been mentioned by many PHP4 has native support for sessionsand the much
touted XML. While this makes PHP a competitor in theApplication
server languages arena, there is another core aspect to PHP4. Itis faster.
PHP3 used to
parse line by line, while PHP acts like a compiler. This alongwith the ZEND
optimizer makes PHP4 almost always faster than PHP3.I'm not sure about support
for COM, it has caught my attention only in PHP4.If it was present in PHP3 I
was not aware of it.Plus PHP4 can run as an Apache module, again this
could have come in thelate versions of PHP3.
65. What are
the differences between include() and include_once()functions?
Answer: include_once()
will use the specified file only once. include and require willuse the
specified file as many time we want. If include_once() is used before withsame
name, it can not done again
66. Explain
mysql optimization?
Answer:Optimization
is a complex task because ultimately it requires understanding of theentire
system. Although it may be possible to perform some local optimizations
withlittle knowledge of your system or application, the more optimal you want
yoursystem to become, the more you will have to know about it. The most
importantfactor in making a system fast is the basic design. You also need to
know what kindsof things your system will be doing, and what your bottlenecks
are.
67. What is the
difference between Reply-to and Return-path in the headers of a mailfunction?
Answer:Reply-to:
Reply-to is where to delivery the reply of the mail.Return-path: Return path is
when there is a mail delivery failure occurs then whereto delivery the failure
notification.
68. Will comparison of string
"10" and integer 11 work in PHP?
Answer: Yes, internally PHP will cast everything to
the integer type, so numbers 10 and 11 will be compared.
69. When are you supposed to use endif
to end the conditional statement?
Answer: When the original if was followed by : and
then the code block without braces.
70. Explain the ternary conditional
operator in PHP?
Answer: Expression preceding the ? is evaluated, if
it"s true, then the expression preceding the : is executed,
otherwise, the expression following : is executed.
71. How do I find out the number of
parameters passed into function in PHP?
Answer: func_num_args() function returns the number
of parameters/arguments passed to a function in PHP.
72. What"s the difference between
accessing a class method via -> and via ::?
Answer: In PHP, :: is allowed to access methods
that can perform static operations, i.e. those, which do not require object
initialization.
73. Are objects passed by value or by
reference?
Answer: Everything is passed by value. In PHP4 it's
true, BUT in PHP5 absolutely not - all objects are passed by reference.
74. How do you call a constructor for a
parent class?
Answer: parent::constructor($value)
75. What"s the special meaning of
__sleep and __wakeup?
Answer: __sleep returns the array of all the
variables than need to be saved, while __wakeup retrieves them.
76. Would you initialize your strings
with single quotes or double quotes in PHP?
Answer: Since the data inside the single-quoted
string is not parsed for variable substitution, it"s always a
better idea speed-wise to initialize a string with
single quotes, unless you specifically need variable
substitution.
77. What"s the difference between
htmlentities() and htmlspecialchars()?
Answer: htmlspecialchars only takes care of <,
>, single quote ", double quote " and ampersand. htmlentities
translates all occurrences of character sequences
that have different meaning in HTML.
78. What"s the difference between
md5(), crc32() and sha1() crypto on PHP?
Answer: The major difference is the length of the
hash generated. CRC32 is, evidently, 32 bits, while sha1()
returns a 128 bit value, and md5() returns a 160
bit value. This is important when avoiding collisions.
79. What is a Session in PHP?
Answer
A PHP session is no different from a
normal session. It can be used to store information on the server for future
use. However this storage is temporary and is flushed out when the site is
closed. Sessions can start by first creating a session id (unique) for each user.
Syntax : session_start()
80. How can we
increase the execution time of a php script?
Answer:Set
max_execution_time variable in php.ini file to your desired
time in second.
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