Class XII Term-II
INFORMATION PRACTICES (065)
MOST COMMON QUESTIONS
LAST MINUTE PREPARATION
With solution
SINGLE ROW FUNCTION VS MULTIPLE ROW FUNCTION
Single Row Function
Multiple Row Function
Returns single result for each row
when applied to a table
Returns single result by grouping all
rows of table when applied
STRING, NUMERIC & DATETIME
functions
AGGREGATE FUNCTIONS
Can be used with SELECT, WHERE
Clause
Can use GROUP BY Clause
ROUND()
It rounds and display a number to the no of decimal places specified.
Syntax:
ROUND( Number/fieldname, no of decimal places)
SUBSTR()
It retrieves first occurrence of specific part of given string starting at the specified
character to the number of character specified.
Syntax:
MID(String/fieldname(s), Start_index, Length)
Substr(String/fieldname(s), Start_index, Length)
Substring(String/fieldname(s), Start_index, Length)
INSTR()
It returns position of first occurrence of the substring from given string data.
Syntax:
INSTR(String/fieldname(s), substring)
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TRIM()
It returns string after removing leading and trailing spaces from given string data.
Syntax:
TRIM(String/fieldname(s))
NOW()
It display current date and time.
Syntax:
NOW()
MONTHNAME()
It display name of month of date passed.
Syntax:
MONTHNAME(date/datetime expression)
YEAR()
It extract and display year part of given date.
Syntax:
YEAR(date/datetime expression)
AGGREGATE FUNCTIONS:
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Group Functions
Multiple Row Functions
Works on Multiple rows together rather single row
helps to summarize large volume of data
Returns single value for entire table or set of rows
only one column can be specified within parenthesis of aggregate function.
multiple aggregate functions can be used together in a SQL Query by separating
them using comma.
SUM(), AVG(), MIN(), MAX(), COUNT(), COUNT(*)
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DIFFERENCE BETWEEN COUNT() AND COUNT(*)
Count(*)
Count()
It selects all columns from table
than counts all rows
It selects only one column that is
passed as argument within it and
than counts rows.
It counts rows containing NULL
values while counting.
It ignores rows containing NULL
values while counting.
GROUP BY
The Group By clause helps to summarize large volume of records. It combines all those
records that have identical values in a particular field or a group of fields and produces
one summary record per group.
SYNTAX:
SELECT FIELDNAME, AGG_FUN(FIELDNAME)
FROM <TABLENAME>
WHERE <CONDITION>
GROUP BY <FIELD NAME>
HAVING <CONDITION>
ORDER BY <FIELDNAME>
WHERE VS HAVING
Where Clause
Having Clause
It can be used with SELECT,
UPDATE or DELETE statement
It can be used without GROUP BY
clause
It can not contain aggregate
functions
It acts as pre filter in query
It can only be used with SELECT
statement
It cannot be used without GROUP
BY clause
It can contain aggregate functions
It is used to filter single record
It is used to filter group of records
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It acts as post filter in query
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LAN VS MAN VS WAN
LAN
Stands for local area
network
High data transfer rate
MAN
Stands for metropolitan
area network
Moderate data transfer rate
Covers range of 1km
Private
Covers range of 40km
Private/public
WAN
Stands for wide area
network
Less as compared to man’s
data transfer rate
No boundary
public
SWITCH VS HUB
SWITCH
It is intelligent device
It is active
HUB
It is dumb device
It is passive
ROUTER VS GATEWAY
ROUTER
it tries to find best rout to transmit data
over WAN
It is active
GATEWAY
It considered as entry exit point for a
network
It is passive
Star Topology
It is one of the most commonly used topology. In a star topology, nodes are not
connected to each other, instead are connected to a central device called hub or switch.
Information sent by a computer is received by hub/switch, which than determines which
node that data needs to send.
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URL AND ITS COMPONENT
A URL stands for Uniform Resource Locator also referred to as web address is a unique
identifier used to specify unique address of a website. For example
https://www.microsoft.com
Components of URL:
Protocol
Name or Address of Server
Location of File on Server
SMTP:
Stands for Simple Mail Transfer Protocol. SMTP is a protocol used for email services.
HTTP:
stands for Hypertext Transfer Protocol. HTTP stands for HyperText Transfer Protocol. It is
the primary protocol used to access the World Wide Web.
List name of chat software?
WhatsApp, Slack, Skype, Yahoo Messenger, Google Talk, Facebook Messenger, Google
Hangout
VoIP
Voice Over Internet Protocol is a technology that makes audio and video calls possible from
any internet-connected device having a microphone and speakers.
It is useful because of itsLower cost
Increased functionality
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STATIC VS DYNAMIC PAGE
Static page
Content of static page does not
change frequently
Content Of static page remain same
for all the user
Static pages generally created in
HTML, JavaScript and CSS
Dynamic page
Content of dynamic page changes
frequently
Content of dynamic page can be
different for different user
Dynamic web page is created using
various languages such as PHP,
Java, Python, ASP, JS etc.
WEB HOSTING
Web hosting is a service that allows us to put a website or a web page onto the Internet,
and make it a part of the World Wide Web.
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