Data Modeling: Type + SubTypes

Suppose I have a database that includes 5 different "types" of people, and
each person could simultaneously be of multiple types (the types don't
really matter... so pretend it has doctors, lawyers, janitors, students, and
customers).
My Question: In general, is it perfectly acceptable in a scenario like this
to have one People table for common attributes and then 5 additional "person
type-specific" tables (e.g., a Doctors table, Lawyers, Janitors, Students,
and Customers tables) that each hold type-specific attributes?
Or is there a *general* recommendation to go with 5 tables total and
duplicate the common attributes amongst the tables.
Please understand my objective is to come up with a solid relational
database design - NOT simply to emulate the object-oriented programming
concept of inheritance in my database; and yes, I do understand the issues
related to choice of primary key (my plan is to use an IDENTITY property to
glue the People table with the various "person type" tables, and then have a
UNIQUE constraint on the "real" natural keys per "person type").
Thanks!"Jefffff" <A@.B.COM> wrote in message
news:edGY0teUGHA.2704@.tk2msftngp13.phx.gbl...
> Suppose I have a database that includes 5 different "types" of people, and
> each person could simultaneously be of multiple types (the types don't
> really matter... so pretend it has doctors, lawyers, janitors, students,
> and customers).
> My Question: In general, is it perfectly acceptable in a scenario like
> this to have one People table for common attributes and then 5 additional
> "person type-specific" tables (e.g., a Doctors table, Lawyers, Janitors,
> Students, and Customers tables) that each hold type-specific attributes?
> Or is there a *general* recommendation to go with 5 tables total and
> duplicate the common attributes amongst the tables.
> Please understand my objective is to come up with a solid relational
> database design - NOT simply to emulate the object-oriented programming
> concept of inheritance in my database; and yes, I do understand the issues
> related to choice of primary key (my plan is to use an IDENTITY property
> to glue the People table with the various "person type" tables, and then
> have a UNIQUE constraint on the "real" natural keys per "person type").
> Thanks!
>
>
Your first suggestion is better. The following article explains how and why
tables should not duplicate each other (more precisely, their predicates
should not overlap):
http://www.dbdebunk.com/page/page/622331.htm
David Portas, SQL Server MVP
Whenever possible please post enough code to reproduce your problem.
Including CREATE TABLE and INSERT statements usually helps.
State what version of SQL Server you are using and specify the content
of any error messages.
SQL Server Books Online:
http://msdn2.microsoft.com/library/ms130214(en-US,SQL.90).aspx
--|||Why do I find that amusing :)
"David Portas" <REMOVE_BEFORE_REPLYING_dportas@.acm.org> wrote in message
news:%23CQjX2eUGHA.1564@.TK2MSFTNGP11.phx.gbl...
> http://www.dbdebunk.com|||Think about it this way and it might be clearer:
People are people and have attributes that describe them as a person (Name,
DOB, etc)
People can play different roles such as Doctor, Lawyer, etc
So, you would likely have a table named Person to store those attributes
that are about the person
Then, seperate tables for each role the person may play
"Jefffff" <A@.B.COM> wrote in message
news:edGY0teUGHA.2704@.tk2msftngp13.phx.gbl...
> Suppose I have a database that includes 5 different "types" of people, and
> each person could simultaneously be of multiple types (the types don't
> really matter... so pretend it has doctors, lawyers, janitors, students,
> and customers).
> My Question: In general, is it perfectly acceptable in a scenario like
> this to have one People table for common attributes and then 5 additional
> "person type-specific" tables (e.g., a Doctors table, Lawyers, Janitors,
> Students, and Customers tables) that each hold type-specific attributes?
> Or is there a *general* recommendation to go with 5 tables total and
> duplicate the common attributes amongst the tables.
> Please understand my objective is to come up with a solid relational
> database design - NOT simply to emulate the object-oriented programming
> concept of inheritance in my database; and yes, I do understand the issues
> related to choice of primary key (my plan is to use an IDENTITY property
> to glue the People table with the various "person type" tables, and then
> have a UNIQUE constraint on the "real" natural keys per "person type").
> Thanks!
>
>

Data Grouping

hi,

I want to group data in matrix column. Lets say i have a field say Weekday which has weekdays from monday to friday. then suppose i have measure "my expenditure".

I will place Weekdays in column field of matrix and "my expenditure" in data field". lets not worry about rows.

Now i want something like this.

Group my expenditure in three categories like

1. My expenditure on monday

2. My expenditure on tuesday

3. My expenditure on days other than monday and tuesday.(means it should show me data for wednesday,thursday,friday and also if no weekday is entered)

what I am doing now is i m writting IIF expression in the column field but with that i get data for monday and tuesday but data for all the other days is not getting clubbed.

how can i do this?

Thanks

rohit

Is my problem not clear?

Please anybody help!!

Thanks & regards

|||

Instead of using a matrix table top create your report, you could use a query to pivot your data.

(SUM(CASE WHEN DAY = 'MONDAY' THEN EXPENDITURE ELSE 0 END)) AS [MON EXP],

(SUM(CASE WHEN DAY = 'TUESDAY' THEN EXPENDITURE ELSE 0 END)) AS [TUES EXP],

(SUM(CASE WHEN (DAY <> 'MONDAY' AND DAY <>'TUESDAY') THEN EXPENDITURE ELSE 0 END)) AS [ROW EXP]

FROM EXPENDITURE_TABLE

Then insert the fields from the datasource into a std table component in a report.