Questions : 25    What’s the difference between “UNION” and “UNION ALL” ?
Answers : 25
UNION SQL syntax is used to select information from two tables. But it selects only distinct records

from both the table. , while UNION ALL selects all records from both the tables. (more…)

Database (DBMS) interview questions and answers are below
Questions : 1     What is database or database management systems (DBMS)? and – What’s the difference
between file and database? Can files qualify as a database?
Answers : 1
Database provides a systematic and organized way of storing, managing and retrieving from collection
of logically related information.
Secondly the information has to be persistent, that means even after the application is closed the
information should be persisted.
Finally it should provide an independent way of accessing data and should not be dependent on the
application to access the information. (more…)

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 (more…)

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) (more…)

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. (more…)

Questions : 1 Who is the father of PHP ?
Answers : 1 Rasmus Lerdorf is known as the father of PHP.
Questions : 2 What is the difference between $name and $$name?
Answers : 2 $name is variable where as $$name is reference variable
like $name=sonia and $$name=singh so $sonia value is singh.Questions :
3 How can we submit a form without a submit button?
Answer : 3 Java script submit() function is used for submit form without submit button
on click call document.formname.submit() (more…)

I would like to share some commonly used vi editor command which will be useful for
the beginners who love to work in vi editor.
This will be more useful for new linux users. (more…)

chmod stands for change mode, which changes the file or directory mode bits. To put it simply,
use chmod command to change the file or directory permissions.

Following is a sample of ls -l command output. In this, the 9 characters from 2nd to
10th position represents the permissions for the 3 types of users.
-rw-r–r– 1 john john 272 Mar 17 08:22 test.txt (more…)