Presented by:- HAMMAD AHMAD PGD-IT (35) Govt. Gordon College Rawalpindi

1. 1 Hammad Ahmad Govt. Gordon College Computer Department Rawalpindi
“CONVERSION TO 3RD nF AND ERD DESIGN OF
POINT OF SALE INFORMATION SYSTEM OF
PAKISTAN GROUP OF SUPER STORES (PGSS)”
Presented by: - Presented to: -
HAMMAD AHMAD Sir Farhad M. Riaz
PGD-IT (35) Lecturer
hammadahmad29@yahoo.com Govt. Gordon College
+92-312-500 22 47 Computer Section Rwp
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Jan 31 2012

2. 2 Hammad Ahmad Govt. Gordon College Computer Department Rawalpindi
POINT OF SALE INFORMATION SYSTEM
Conversion to 3rd nF
Relation
Repeating Group
I-Price/unit
C-Payment
M-Address
C-Address
C-Invoice
M-Name
C-Name
I-Name
C-DOP
Mode
M-ID
C-QP
C-ID
I-ID
No.
101 Hammad F-block 31Jan2012 02 Cash 00111 3333 Shampoo 300 98711 Pantene Karachi
Rwp
Hammad F-block 01Feb2012 01 Cash 00542 3651 Perfume 1750 92410 Chestity Karachi
Rwp
102 Badar Defense 03Feb2012 06 Credit 00875 3210 Cooking 750 95001 Dalda Karachi
Lhr Oil 5kg
Badar Defense 04Feb2012 02 Home 00921 3001 Cold 70 98540 Cocacola USA
Lhr Delivery drink 1Ltr
The above relation is not in 1st nF because it has repeating group as highlighted above. It is a repeating group
because a customer can purchase different items.
It has following anomalies:-
 Insertion anomaly
In primary key column, there cannot be a null value. But if a customer purchases items on separate dates
then the data cannot be entered.
 Deletion anomaly
If the customer information is deleted then the item & manufacturer information is also deleted. So it
can cause a lot of damage to the organization.
 Updating anomaly
The item price and detail vary with the item no. so the whole rows and columns are to be updated with
the change. Since there are also customer and manufacturer in the table so it is very difficult to update
any of the categories.
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Jan 31 2012

3. 3 Hammad Ahmad Govt. Gordon College Computer Department Rawalpindi
1st nF
The relation is converted in 1st nF by forming a composite key of C-ID and I-ID as shown below:-
Composite Key
I-Price/unit
C-Payment
M-Address
C-Address
C-Invoice
M-Name
C-Name
I-Name
C-DOP
Mode
M-ID
C-QP
C-ID
I-ID
No.
101 3333 Hammad F-block 02 31Jan2012 Cash 00111 Shampoo 300 98711 Pantene Karachi
Rwp
101 3651 Hammad F-block 01 01Feb2012 Cash 00542 Perfume 1750 92410 Chastity Karachi
Rwp
102 3210 Badar Defense 06 03Feb2012 Credit 00875 Cooking 750 95001 Dalda Karachi
Lhr Oil 5kg
102 3001 Badar Defense 02 04Feb2012 Home 00921 Cold 70 98540 CocaCola USA
Lhr Delivery drink
1Ltr
But the above relation is not in 2nd nF because of the partial dependency of the non-key attributes as shown
with highlighted arrows above. These partial dependent attributes are as follows:-
I-ID I-Name, I-Price /unit, M-ID, M-Name, M-Address.
C-ID C-Name, C-Address, C-QP, C-DOP, C-Payment Mode.
It has following anomalies:-
 Insertion anomaly
If a new item is introduced or a customer wants to register himself then the data can’t be entered
without C-ID & I-ID respectively.
 Deletion anomaly
If a customer or item information is deleted then the whole information customer, item and
manufacturer will be deleted.
 Updating anomaly
It is very difficult to update the information. If there is any change in the data then the whole rows and
columns are to be updated.
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Jan 31 2012

4. 4 Hammad Ahmad Govt. Gordon College Computer Department Rawalpindi
2nd nF
The 1st nF relation is converted in 2nd nF by normalizing it into C-ID & I-ID entities. It is normalized as
follows:-
Transitive Dependency
 Customer
C-Payment
C-Address
C-Invoice
C-Name
C-DOP
Mode
C-QP
C-ID
No.
101 Hammad F-block Rwp 02 31Jan2012 Cash 00111
101 Hammad F-block Rwp 01 01Feb2012 Cash 00542
102 Badar Defense Lhr 06 03Feb2012 Credit 00875
102 Badar Defense Lhr 02 04Feb2012 Home Delivery 00921
 Item
M-Address
Price/unit
M-Name
I-Name
M-ID
I-ID
I-
3333 Shampoo 300 98711 Pantene Karachi
3651 Perfume 1750 92410 Chastity Karachi
3210 Cooking Oil 750 95001 Dalda Karachi
5kg
3001 Cold drink 1Ltr 70 98540 CocaCola USA
Transitive Dependency
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Jan 31 2012

5. 5 Hammad Ahmad Govt. Gordon College Computer Department Rawalpindi
The above entities are not in 3rd nF because of the transitive dependency of non-key attributes. The
transitive dependent non-key attributes are as follows:-
C-QP
M-ID
C-Payment
C-DOP
Mode
AND
M-
M-Name
C-Invoice
Address
No.
It has following anomalies:-
 Insertion anomaly
If an unregistered customer purchases some items then his information cannot be entered. On the other
hand a new manufacturer’s information cannot be entered without item id.
 Deletion anomaly
By deleting customer information or item information the invoice information and manufacturer’s
information is also deleted.
 Updating anomaly
Still it is very difficult to update the information. If there is any change in the data then the whole rows
and columns are to be updated.
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Jan 31 2012

6. 6 Hammad Ahmad Govt. Gordon College Computer Department Rawalpindi
3rd nF
The 2nd nF relation is converted into 3rd nF by further normalizing the customer and item entities. They are
normalized as follows:-
 Customer Foreign Key
Address
C-Name
Invoice
C-ID
No.
C-
C-
101 Hammad F-block Rwp 00111
101 Hammad F-block Rwp 00542
102 Badar Defense Lhr 00875
102 Badar Defense Lhr 00921
 Invoice No.
C-Invoice
Payment
C-DOP
Mode
C-QP
No.
C-
00111 02 31Jan2012 Cash
00542 01 01Feb2012 Cash
00875 06 03Feb2012 Credit
00921 02 04Feb2012 Home Delivery
 Item Foreign Key
Price/u
I-Name
M-ID
I-ID
nit
I-
3333 Shampoo 300 98711
3651 Perfume 1750 92410
3210 Cooking Oil 5kg 750 95001
3001 Cold drink 1Ltr 70 98540
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Jan 31 2012

7. 7 Hammad Ahmad Govt. Gordon College Computer Department Rawalpindi
 Manufacturer
M-Name
Address
M-ID
M-
98711 Pantene Karachi
92410 Chastity Karachi
95001 Dalda Karachi
98540 CocaCola USA
 Customer-Item (C-I Gerund)
C-ID
I-ID
101 3333
101 3651
102 3210
102 3001
Now the relation is in 3rd nF. The anomalies are reduced to maximum extent. Now each entity has its own
record. Since “The Prestigious Group of Super Stores” has four other branches in Pakistan, so the above
entities have a homogenous distributed system spread over Pakistan.
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Jan 31 2012

8. 8 Hammad Ahmad Govt. Gordon College Computer Department Rawalpindi
ERD DESIGN
ITEM
MANUFACTURER
C-I
CUSTOMER
INVOICE
NO.
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Jan 31 2012