Primary Key

Nov 8, 2007

Hi..

I'm going to build database of university, but I have problem with primaru key,

This is the situation:

there are many faculities and each one has many departments,

each department has many courses,

each course has many sections..

The problem:

I want to make those fields in the same table and make the primary key generate from other fields,

(i.e)

I want the faculity be integer from 4 digit "Example the first faculity start with 1000 the second 2000 and so on" and the the department of each faculity will generate its value from the faculity number+interger number from 3digit "Example the department of the first faculity start with 1100 and the second on will be 1200 and so on "

the same thing will repeate for courses and sections so the sectionsID will be the primary key.

Do you know hoew this idea can be implement by SQL server 2005?

Please help me as soon as possible.

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Convert Composite Primary Key Into Simple Primary Key

Jan 11, 2007

Uma writes "Hi Dear,
I have A Table , Which Primary key consists of 6 columns.
total Number of Columns in the table are 16. Now i Want to Convert my Composite Primary key into simple primary key.there are already 2200 records in the table and no referential integrity (foriegn key ) exist.

may i convert Composite Primary key into simple primary key in thr table like this.

Thanks,
Uma"

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Adding Primary Key To A Table Which Has Already A Primary Key

Aug 28, 2002

Hi all,
Can anyone suggest me on Adding primary key to a table which has already a primary key.

Thanks,
Jeyam

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Auto Incremented Integer Primary Keys Vs Varchar Primary Keys

Aug 13, 2007

Hi,

I have recently been looking at a database and wondered if anyone can tell me what the advantages are supporting a unique collumn, which can essentially be seen as the primary key, with an identity seed integer primary key.

For example:

id [unique integer auto incremented primary key - not null],
ClientCode [unique index varchar - not null],
name [varchar null],
surname [varchar null]

isn't it just better to use ClientCode as the primary key straight of because when one references the above table, it can be done easier with the ClientCode since you dont have to do a lookup on the ClientCode everytime.

Regards
Mike

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SQL Server 2008 :: Change Primary Key Non-clustered To Primary Key Clustered

Feb 4, 2015

We have a table, which has one clustered index and one non clustered index(primary key). I want to drop the existing clustered index and make the primary key as clustered. Is there any easy way to do that. Will Drop_Existing support on this matter?

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4 Key Primary Key Vs 1 Key 'artificial' Primary Key

Jan 28, 2004

Hi all

I have the following table

CREATE TABLE [dbo].[property_instance] (
[property_instance_id] [int] IDENTITY (1, 1) NOT NULL ,
[application_id] [int] NOT NULL ,
[owner_id] [nvarchar] (100) NOT NULL ,
[property_id] [int] NOT NULL ,
[owner_type_id] [int] NOT NULL ,
[property_value] [ntext] NOT NULL ,
[date_created] [datetime] NOT NULL ,
[date_modified] [datetime] NULL
)

I have created an 'artificial' primary key, property_instance_id. The 'true' primary key is application_id, owner_id, property_id and owner_type_id

In this specific instance
- property_instance_id will never be a foreign key into another table
- queries will generally use application_id, owner_id, property_id and owner_type_id in the WHERE clause when searching for a particular row
- Once inserted, none of the application_id, owner_id, property_id or owner_type_id columns will ever be modified

I generally like to create artificial primary keys whenever the primary key would otherwise consist of more than 2 columns.

What do people think the advantages and disadvantages of each technique are? Do you recommend I go with the existing model, or should I remove the artificial primary key column and just go with a 4 column primary key for this table?

Thanks Matt