Added Residential and NonResidential entities to customer as subtype.
computer science
Description
1) ERD Changes
1.
Removed Report entity
2.
Added Residential and NonResidential entities
to customer as subtype.
3.
Added watermeter_id to Reading
entity to provide a 1:N relationship
4.
Added meterreader_id to
WaterMeter entity to provide a 1:N relationship
5.
Added reading_date to Reading
entity and removed lastmeterread
6.
Added status to WaterMeter
entity
7.
Added Account Entity
8.
Added serial number on water
meter
2) Data Dictionary
CUSTOMER
|
Attribute |
Description |
Required? |
Not Null? |
Key |
Data type(size) |
|
CustomerID |
Unique ID for each customer |
Yes |
Ö |
Primary |
Varchar2 (7) |
|
CustomerName |
Customer’s Name |
Yes |
Ö |
|
Char (100) |
|
CustomerType |
Customer’s Type |
Yes |
Ö |
|
Char (30) |
RESIDENTIAL
|
Attribute |
Description |
Required? |
Not Null? |
Key |
Data type(size) |
|
ResidentialID |
Unique ID of residential |
Yes |
Ö |
Primary |
Varchar2 (7) |
|
CustomerID |
Unique ID of customer |
Yes |
Ö |
Foreign |
Varchar2 (7) |
|
Address |
Customer’s Address |
Yes |
Ö |
|
Varchar2 (100) |
NONRESIDENTIAL
|
Attribute |
Description |
Required? |
Not Null? |
Key |
Data type(size) |
|
NonresidentialID |
Unique ID of
non-residential |
Yes |
Ö |
Primary |
Varchar2 (7) |
|
Customer_ID |
Unique ID of customer |
Yes |
Ö |
Foreign |
Varchar2 (4) |
|
Address |
Customer’s Address |
Yes |
Ö |
|
Varchar2 (100) |
WATERMETER
|
Attribute |
Description |
Required? |
Not Null? |
Key |
Data type(size) |
|
WatermeterID |
Unique ID assigned for
each watermeter |
Yes |
Ö |
Primary Foreign |
Varchar2 (10) |
|
CustomerID |
Unique ID of customer |
Yes |
Ö |
Foreign |
Varchar2 (7) |
|
MeterreaderID |
Meterreader who reads the
watermeter |
Yes |
Ö |
Foreign |
Varchar2 (7) |
|
WMAddress |
Address of watermeter deployed |
Yes |
Ö |
|
Varchar2 (100) |
|
DeployedDate |
Date watermeter deployed |
Yes |
Ö |
Related Questions in computer science category
Get Higher Grades Now
Tutors Online
Get Free Quote! 366 Experts Online |
