RE: opinions on naming primary keys in new database (seriously)

From: <G.Plivna_at_itsystems.lv>
Date: Thu, 08 Mar 2001 09:57:22 -0800
Message-ID: <F001.002C74A0.20010308091106@fatcity.com>

We have strict algorithm for table columns, keys, sequences and indexes

All tables have 3 cahracter long aliases So all columns are in form <alias>_<colname> for example emp_id, emp_name, emp_adr_id, adr_street_name
All tables have surrogate primary key column in form <alias>_id
All primary keys are named <alias>_pk
All foreign key columns are in form <alias1>_<alias2>_id
All foreign keys are named <alias1>_<alias2>_fk
If there are more than one foreign key to another table then foreign keys are named <alias1>_<alias2>_<meaningful_name>_fk
All unique keys are named <alias>_<meaningful_name>_uk
Every table has its own sequence in form <alias>_seq
Every index on foreign key is in form <alias1>_<alias2>_fk_i
Every index on one column is in form <full_column_name>_i
Every index on two or more columns is in form <alias>_<meaningful_name> _i

The advantages are that one can surely identify object type, object relation with table, not use aliases in almost all selects (aliases must be in self joins).
Disadvantage - at least one - longer column names

I don't think it is invention of our organization, for example, Oracle Designer uses almost the same scheme

But I think every apprach is good enough if it isn't haotic and You are satisfied with it

Gints Plivna

                                                                                       
                               
                    "Jeff Cox"                                                         
                               
                    <jeff.cox_at_ips-se        To:     Multiple recipients of list 
ORACLE-L <ORACLE-L_at_fatcity.com>       
                    ndero.com>              cc:                                        
                               
                    Sent by:                Subject:     RE: opinions on naming 
primary keys in new database          
                    root_at_fatcity.com        (seriously)                                
                               
                                                                                       
                               
                                                                                       
                               
                    01.03.08 18:10                                                     
                               
                    Please respond                                                     
                               
                    to ORACLE-L

Hugh,

You are right that Richard Barker says not to use an entity name as part of an attribute name. (CASE*METHOD Entity Relationship Moddelling, by Richard Barker, page 3-9) And I believe Oracle still gives out this book in their Data Modeling class.

I have seen databases that completely follow this method and others that include the table name in every column. As far as naming your primary key as a column called 'key', I don't like it either.

I am also curious to see what is the preference of other list members.

Regards,

Jeff Cox
IPS-Sendero
Scottsdale, AZ

-----Original Message-----
Sent: Wednesday, March 07, 2001 4:58 PM
To: oracledba_at_lazydba.com

Hello,

I wanted to get the lists opinion on the preference of naming primary keys.

Please see my example below with the CUSTOMER table, and the customer TYPE table. The column 'type_id' is a foreign key referencing the TYPE table. This is just an example to get opinions.

CUST               TYPE
+---------+       +------+


| id      |       |id    |

| name    |       |desc  |

| type_id |>------|      |

+---------+       +------+

I like having my primary keys called id, and not including the table names in the columns of the original table. For example, in the CUST table, we would not have 'cust_id' as the primary key, we would just call it 'id'. But having 'type_id' as a column of the CUST table is okay because that is a
foreign key, and not an attribute of the original CUST entity.

Including the table name in a column that is not a foreign key, I believe, is redundant and not necessary. (I also remember reading this in a Richard Barker book.)

All foreign keys would then have the standard of table_column, with the exception of tables with multiple foreign keys from the same table, and recursive relationships - which would then just include a more descriptive table_column name.

This way, when you do a describe on a table, you will immediately be able to
tell what are the foreign keys, and the primary keys. (I also believe in surrogate keys for most tables, so the problem of having a composite key is not an issue here.) I think that this will later make the database easier to understand to new DBAs and duhvelopers, which would have been nice when I
worked on my first database.

My questions:

What is your preference with primary and foreign keys - if you could design a database from scratch?
Am I off my rocker thinking that this is a good way to design a database?
We have a developer who wants to name all of our primary keys, 'key', and I am trying to convince her that we should use 'id' or 'nbr' instead. Has anyone ever used 'key' as the primary key of a table? This seems like it would be confusing when

All constructive criticism is welcomed.

Thank you,

Hugh

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Received on Thu Mar 08 2001 - 11:57:22 CST