Re: [GENERAL] simulate multiple primary keys

2009-07-02 Thread Lennin Caro



--- On Thu, 7/2/09, Brandon Metcalf  wrote:

> From: Brandon Metcalf 
> Subject: [GENERAL] simulate multiple primary keys
> To: pgsql-general@postgresql.org
> Date: Thursday, July 2, 2009, 5:27 PM
> I have the following table:
> 
>   gms=> \d jobclock
>                
>                
>               Table
> "public.jobclock"
>      Column    |   
>           Type     
>         |       
>                
>    Modifiers
>  
> -++
>    jobclock_id | integer     
>                
>   | not null default
> nextval('jobclock_jobclock_id_seq'::regclass)
>    employee_id | integer     
>                
>   | not null
>    machine_id  | character
> varying(4)           |
> not null
>    workorder   | character
> varying(8)           |
> not null
>    operation   |
> integer             
>           | not null
>    bartype     |
> character varying(10)          |
> not null
>    clockin     |
> timestamp(0) without time zone | not null
>    clockout    | timestamp(0)
> without time zone | default NULL::timestamp without time
> zone
>    comments    | character
> varying(255)         | default
> NULL::character varying
>   Indexes:
>       "jobclock_pkey" PRIMARY KEY, btree
> (jobclock_id)
>   ...
> 
> I need to keep jobclock_id unique and not null, but I also
> need to
> ensure that no row is duplicated.  Is my best bet to
> drop the current
> primary key and make a primary key out of the columns that
> I want to
> ensure remain unique from row to row?
> 
> Thanks.
> 
> 
> -- 
> Brandon
> 
> -- 

It depends of a lot of variables, take two stage:

Stage 1
one  employee_id can use some machine_id create you can create a unique key to 
employee_id


Stage 2
one  employee_id can use one machine_id create you can create a unique key to 
employee_id,machine_id

is a example, but i think you have to normalize the table




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Re: [GENERAL] simulate multiple primary keys

2009-07-02 Thread Bill Moran
In response to Brandon Metcalf :

> I have the following table:
> 
>   gms=> \d jobclock
>   Table "public.jobclock"
>  Column|  Type  |   
> Modifiers
>   
> -++
>jobclock_id | integer| not null default 
> nextval('jobclock_jobclock_id_seq'::regclass)
>employee_id | integer| not null
>machine_id  | character varying(4)   | not null
>workorder   | character varying(8)   | not null
>operation   | integer| not null
>bartype | character varying(10)  | not null
>clockin | timestamp(0) without time zone | not null
>clockout| timestamp(0) without time zone | default NULL::timestamp 
> without time zone
>comments| character varying(255) | default NULL::character 
> varying
>   Indexes:
>   "jobclock_pkey" PRIMARY KEY, btree (jobclock_id)
>   ...
> 
> I need to keep jobclock_id unique and not null, but I also need to
> ensure that no row is duplicated.  Is my best bet to drop the current
> primary key and make a primary key out of the columns that I want to
> ensure remain unique from row to row?

Your primary key can span multiple columns, i.e.
PRIMARY KEY(jobclock_id, employee_id, machine_id)
Could be more columns.

Keep in mind that this ensures that the combination of all those
columns is unique, which may or may not be what you want. 

-- 
Bill Moran
http://www.potentialtech.com
http://people.collaborativefusion.com/~wmoran/

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Re: [GENERAL] simulate multiple primary keys

2009-07-02 Thread Brandon Metcalf
M == matthew.hart...@krcc.on.ca writes:

 M> Just create a unique constraint on all of the columns.


Ah.  Didn't realize you could specify more than one column as part of
a unique constraint.

Thanks.

-- 
Brandon

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Re: [GENERAL] simulate multiple primary keys

2009-07-02 Thread Hartman, Matthew
Just create a unique constraint on all of the columns.


Matthew Hartman
Programmer/Analyst
Information Management, ICP
Kingston General Hospital
(613) 549- x4294 
 

> -Original Message-
> From: pgsql-general-ow...@postgresql.org [mailto:pgsql-general-
> ow...@postgresql.org] On Behalf Of Brandon Metcalf
> Sent: Thursday, July 02, 2009 1:28 PM
> To: pgsql-general@postgresql.org
> Subject: [GENERAL] simulate multiple primary keys
> 
> I have the following table:
> 
>   gms=> \d jobclock
>   Table "public.jobclock"
>  Column|  Type  |
> Modifiers
>
-++-
> ---
>jobclock_id | integer| not null default
> nextval('jobclock_jobclock_id_seq'::regclass)
>employee_id | integer| not null
>machine_id  | character varying(4)   | not null
>workorder   | character varying(8)   | not null
>operation   | integer| not null
>bartype | character varying(10)  | not null
>clockin | timestamp(0) without time zone | not null
>clockout| timestamp(0) without time zone | default
NULL::timestamp
> without time zone
>comments| character varying(255) | default
NULL::character
> varying
>   Indexes:
>   "jobclock_pkey" PRIMARY KEY, btree (jobclock_id)
>   ...
> 
> I need to keep jobclock_id unique and not null, but I also need to
> ensure that no row is duplicated.  Is my best bet to drop the current
> primary key and make a primary key out of the columns that I want to
> ensure remain unique from row to row?
> 
> Thanks.
> 
> 
> --
> Brandon
> 
> --
> Sent via pgsql-general mailing list (pgsql-general@postgresql.org)
> To make changes to your subscription:
> http://www.postgresql.org/mailpref/pgsql-general
.now.


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[GENERAL] simulate multiple primary keys

2009-07-02 Thread Brandon Metcalf
I have the following table:

  gms=> \d jobclock
  Table "public.jobclock"
 Column|  Type  |   
Modifiers
  
-++
   jobclock_id | integer| not null default 
nextval('jobclock_jobclock_id_seq'::regclass)
   employee_id | integer| not null
   machine_id  | character varying(4)   | not null
   workorder   | character varying(8)   | not null
   operation   | integer| not null
   bartype | character varying(10)  | not null
   clockin | timestamp(0) without time zone | not null
   clockout| timestamp(0) without time zone | default NULL::timestamp 
without time zone
   comments| character varying(255) | default NULL::character 
varying
  Indexes:
  "jobclock_pkey" PRIMARY KEY, btree (jobclock_id)
  ...

I need to keep jobclock_id unique and not null, but I also need to
ensure that no row is duplicated.  Is my best bet to drop the current
primary key and make a primary key out of the columns that I want to
ensure remain unique from row to row?

Thanks.


-- 
Brandon

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