From: | CS_DBA <cs_dba(at)consistentstate(dot)com> |
---|---|
To: | pgsql-general(at)postgresql(dot)org |
Subject: | Re: check constraint question |
Date: | 2014-04-08 21:26:49 |
Message-ID: | 53446999.1020704@consistentstate.com |
Views: | Raw Message | Whole Thread | Download mbox | Resend email |
Thread: | |
Lists: | pgsql-general |
On 04/08/2014 03:17 PM, Rob Sargent wrote:
> On 04/08/2014 03:09 PM, CS_DBA wrote:
>>
>> On 04/08/2014 02:58 PM, Rob Sargent wrote:
>>> On 04/08/2014 02:51 PM, CS_DBA wrote:
>>>> Hi All
>>>>
>>>> we have a table like so:
>>>>
>>>>
>>>> customer (
>>>> cust_id integer not null primary key,
>>>> cust_group_id integer not null,
>>>> group_account_id integer not null,
>>>> cust_name varchar not null,
>>>>
>>>> ...
>>>> )
>>>>
>>>> we want to force the cust_group_id to be unique across all
>>>> group_account_id's but not necessarily across the entire table
>>>>
>>>> I assume the best approach would be a check constraint yes? Will
>>>> this be excessively poor per performance if the table gets big?
>>>>
>>>> Thoughts?
>>>>
>>>> Thanks in advance
>>>>
>>>>
>>>>
>>>>
>>>>
>>> A unique index on cust_group_id and group_account_id doesn't do it
>>> for you?
>>>
>> oh right! duh! It's been one of those days....
>>
>>
>>
>>
>>
> Which column goes first depends on your lookup expectations.
Thanks!
Here's another one:
customer (
cust_id integer not null primary key,
cust_group_id integer not null,
group_account_id integer not null,
cust_name varchar not null,
cust_template_id integer,
...
)
If cust_template_id IS NOT NULL then it must reference a valid cust_id
Check constraint?
From | Date | Subject | |
---|---|---|---|
Next Message | Rob Sargent | 2014-04-08 21:31:57 | Re: check constraint question |
Previous Message | Rob Sargent | 2014-04-08 21:17:35 | Re: check constraint question |