Hi, I am back again.

Because of "A French vocable got one or more English vocable equivalents and vice versa." there exists a many-to-many relationship between both entities. Therefore this is the...

Hello

What is the primary key of responses, (response_id, range_id)?

To ensure referential integrity all foreign keys (fk) must be set up correctly.
Diaries ---< questions: diary_id is fk...

Hello

that depends on your specific database system. There are Database systems where you can
type in: select myBirthday - now() as "My age is:" ;

You need to know the current-date function...

I did not change your table tbl_Author which already has Author-Name. Therefore I left out your 3rd table !

Hello,

in tbl_poems exists a transitive dependency poem-ID -> Author-ID -> Book-ID. Therefore, this table does not satisfy 3NF. fk Author-ID should be removed and inserted into tbl_Book. The...

Hi rich_m

>>> My team( all freshers) are developing a project that will involve many Modules.

You must be "sophos ke moros" to carry out such database design successfully, which is every...

Ah, you again

Did you proceed in understanding EERM?

I call people who put a magical, universal "id" column with an auto-increment on all their tables "id-iots" ! (Joe Celko)

Hi Mad Pat

In the past all database engines of mysql didn't support any referential integrity by foreign keys. Today, only innodb is able to handle foreign keys correctly (of a kind). Yet my isam...

Hi Mad Pat

I am back again. It's really great that you are using open-office db. You know it's hsqldb, that famous pure Java database system what follows official SQL standard nearly completely....

Hi,



sales and salesitems must be improved: Primary key of salesitems is and only is: (productID, salesID) and nothing else! productID is the primary key of products (you named it ID there),...

Hello mad pat

You need a further table, name it salesitems, where its primary key must be formed from salesID and productID because of many-to-many relationship. Both are also foreign keys. Here...

Hi dakoris73

A constraint is kind of restriction usually to the range of values of a variable.
Given the following create-table statement we can detect several constraints:

create table...

Hello

... "There are 20 types of rating with numerical value ( in look up table)"

How is rating related to numerical value(s) ? Something like this:

AAA 20.5
AA 5.5

or even like this:

Hi monksorlo,

sorry, it has never been my intention to discredit your prof. My given statement sounds kind of sloppy.

Your subtype/supertype is exactly that what I meant with the extension of...

Hi

You may also consider SQL Anywhere and SQL UltraLight from Sybase, exceptional worldwide market leader in mobile computing.

krs,
tesu

Hi again

I have understood you completely. You may study ERP systems (Enterprise Resource Planning) how they handle such problem of separating various customers strictly. There are famous ERP from...

Hi monksorlo

what do you mean by subtype/supertype. Does this deal with the concept of Generalization/Specialization of extended entity relationship model? you may state an example.

If your...

Hi Devin

This is quite a poor idea of designing data models. You will never be able to create good SQL select statements. As you already mentioned, creating and handling stored procedures...

1. Almost all tables are in 2NF (because of always using poor artificial primary keys (pk) there exists lot of transitive dependencies, for example volume_id-->book_no-->volume_no etc). No 3NFs....

Hello Hairymarble,

1. To all appearance almost every table seems to be already in 3NF, but

2. One cannot state anything about 2NF if no primary keys are given. So to proving 3NF is also...

Hi chsarp_vijay,

Derby is pure Java. if you want to use it, you must program Java. Why not using SQL Anywhere/Ultralight from worldwide leader in mobile computing, Sybase? There mobile computing...

Sure there are country codes standardized by ISO 3166, look here:

Some codes from ISO 3166
#
Updated by the RIPE Network Coordination Centre.
#
Source: ISO 3166 Maintenance Agency
#
Latest...

Hi
maybe you would be able to create such table from below list by writing small Python program?

Country Code
----------------------
Afghanistan 93
Albania 355
Algeria 213
American Samoa...

Hi motofoto

There is kind of inheritance - in EERM - where we have Generalization / Specialization, such called isa-relationships. Maybe you should first design an EERM. Your implementation idea...

Hi silverside,

what is a data flow diagram?

krs,
tesu

How to design the appropriate select statement? Also, what if you want to add a further date <date5>? From a theoretical point of view, your design even violates the first normal form (1NF), because...

Great task!
You should also have a look into the ERP branch too. For example SAP R/3, the world largest and most famous ERP system consists of about 18.000 tables (yes, eighteen thousands tables,...

Hi playah,

your data model seems to be able to answer almost all questions you have asked. Also this one: Are there owners who own both, boats and shipyards? select owner.name, shipyard.name,...

hi wzb
Primary key of newRates should consist of Access_Code and operatorID to allow that same access code can be assigned to various operators. Like in:

create table newRates(DestinationName...

Hi wzb


I also assumed this. It has been the reason why I wrote operatorID (pk ??) in newRates. So opeatorID must become part of pk. Hope this will work.

krs,
tesu

Hi wzb,


You can create new table Operators

OPERATORS
• operatorID (pk)
• name

Then add operatorID to RATES

is still 1NF because Emp_Name and job_class only depend on Emp_Num, that is they depend on a part of PK only. Partial dependency must be removed by moving the regarding attributes into an extra...

I have to make an extension:
Sometimes there are more than one superkey of a relation. In such case also all redundant attributes have to be removed and the remaining subsets of attributes are then...

To defeat the anomalies!

btw lich, there is more: BCNF, 4NF, 5NF, and 6NF (in concordance with C.J. Date).

Happy normalizations (as Nixon and Codd didn't say)!

krs,
tesu

hi mertucci,

are in doing data modelling?
Superkey is any subset of attributes that uniquely identifies the tuples of a relation. This subset need not be minimal, that is, one can remove some...

What context, non trivial functional dependencies?

Hi arun,
thx for giving further details. Here is the result (sure, incomplete!) attached.
Drawing of the ERM has been done by tool from Charonware, which has better feature to create entities and...

I have already installed your database, also made some changes.

Pls answer following questions:

1. What is stock allocation?
1.1 an amount of a certain product allocated (= reserved) for...

There is still a problem with entity option. Its pk is made of option_id and option_goup_id, what means that there would be a many-to-many relationship between option_group and a third thing like...

You can upload the SQL script for creating the db, also the mdb file (I have access to acess 2003 only). Better: Upload the ERM, if you have sketched one.