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Discussion about normal forms in SQL


galigannarao

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[quote author=Luv Guru link=topic=219396.msg2702734#msg2702734 date=1312299021]
CITI_c$y CITI_c$y  mari Excel use chestaavaaa
[/quote]dis  @gr33d

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[quote author=galigannarao link=topic=219396.msg2702708#msg2702708 date=1312298799]
Second normal form is valid in a table which have composite primary key which is made with the combination of two columns.So if we have A,B,C,D,E attributes in our table and C,D are fully functional dependent on A,B.But E is partially functional dependent on A,B,Mean if we use Only B to define E coloumn then that will be suffecent.so then we use 2nd normal form & we create two tables with coloumns attributes A,B,C,D and the other table with coloumns attribute B,E.That will be called second normal form.
[/quote]

oka mukka ardam kaledu

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[quote author=ronitreddy link=topic=219396.msg2702747#msg2702747 date=1312299113]
oka mukka ardam kaledu
[/quote]
naku kuda....  !q# ... ee normal forms enni sarlu chaduvukunna ardam ayevi kadu...che denemma.. &*B@

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[quote author=ronitreddy link=topic=219396.msg2702747#msg2702747 date=1312299113]
oka mukka ardam kaledu
[/quote]if A is the primary key and B is the non-primary attribute then B cannot partially depend on A, it has to be completely dependent on A.. anduke non- dependent variable ni vere table loki move chesi normalize chestaru.. adi 2NF

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[quote author=Jeedeelu link=topic=219396.msg2702749#msg2702749 date=1312299125]
create separate tables to eliminate dependencies......
[/quote]separate table create chesedhi dependency kosame kada... 2nd normal form is creating primary key,foreign key relationship between tables..

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[quote author=Antaraatma link=topic=219396.msg2702759#msg2702759 date=1312299230]
if A is the primary key and B is the non-primary attribute then B cannot partially depend on A, it has to be completely dependent on A.. anduke non- dependent variable ni vere table loki move chesi normalize chestaru.. adi 2NF
[/quote] CITI_$D# CITI_$D# CITI_$D# thankyou thankyou thankyou S%Hi S%Hi S%Hi

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[quote author=topulake topu link=topic=219396.msg2702757#msg2702757 date=1312299205]
naku kuda....  !q# ... ee normal forms enni sarlu chaduvukunna ardam ayevi kadu...che denemma.. &*B@
[/quote]

oka table lo mothoam data dump cheyakunda...

inko rendo table create chesi....primary key relaionship eastablish chestharu.....e two tables madhya..


----dis is 2NF....

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[quote author=meghana9 link=topic=219396.msg2702762#msg2702762 date=1312299284]
separate table create chesedhi dependency kosame kada... 2nd normal form is creating primary key,foreign key relationship between tables..
[/quote]

super simple ga baga cheppav  thankyou thankyou thankyou thankyou Ammugif Ammugif Ammugif Ammugif

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[quote author=meghana9 link=topic=219396.msg2702762#msg2702762 date=1312299284]
separate table create chesedhi dependency kosame kada... 2nd normal form is creating primary key,foreign key relationship between tables..
[/quote]
\
dependency in a single table elimanate chesi.......

rendo table create chestaru antunna......

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1NF

Each attribute must be atomic
No repeating columns within a row.
No multi-valued columns.

1NF simplifies attributes
Queries become easier.

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[quote author=Jeedeelu link=topic=219396.msg2702767#msg2702767 date=1312299317]
oka table lo mothoam data dump cheyakunda...

inko rendo table create chesi....primary key relaionship eastablish chestharu.....e two tables madhya..


----dis is 2NF....
[/quote]
got it,,....  thankyou baa

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idanta soothante bayam estundi baa's..... Nenu maa bengalooru pothaa

edanna sinna udyogam seskunta le  &D_@@ &D_@@

vammo endi idanta......  &*B@ &*B@

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2NF

Each attribute must be functionally dependent on the primary key.
Functional dependence - the property of one or more attributes that uniquely determines the value of other attributes.
Any non-dependent attributes are moved into a smaller (subset) table.
2NF improves data integrity.

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oka sql query ni ela tune chestharo kuda cheppandi koncham..performance tune chestharu kada explain plan ala use chesi..dani mida kuda koncham information provide cheyandi plssss..

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