Re: Table with Field Serial - Problem

i really dont need a number generator, only a unique PK. but i want that
this PK be generate automatically

for example i have a Category calling Computer in English but i have the
same Category in Spanish (Computadora) i assigned the ID->1 for both

So if i put the Pk ID in the table2 number i have error for unique
violation when i want INSERT another name in a diferent language for the
same category

For that reason i declare ID in the table2 like a FK from ID in the table1

2013/10/31 Adrian Klaver <adrian(dot)klaver(at)gmail(dot)com>

> On 10/31/2013 09:32 AM, David Johnston wrote:
>
>> Adrian Klaver-3 wrote
>>
>>> Table1
>>>> Column | Type | Modifiers
>>>> ----------+-------------------**__+---------------------------**
>>>> --__--------------------------**----__--
>>>> id | integer | not null default
>>>> nextval('test_table_id_fld___**seq'::regclass)
>>>>
>>>>
>>>> Table2
>>>> Column | Type | related
>>>> ----------+-------------------**__+---------------------------**
>>>> --__--------------------------**----__--
>>>> id_table1 | integer | FK of Table1.id
>>>> id_lang | integer | FK of lang.id
>>>> &lt;http://lang.id&gt;
>>>> name | varchar
>>>>
>>>>
>> The PK for table 2 is composite: the serial key from table 1 + the
>> language
>> id. The table 1 id has to be able to repeat since the same "entity" needs
>> multiple translations. Using a serial on table 2 is also possible but a
>> separate issue and probably not worth adding since you need a unique index
>> on (id_table1, id_lang) regardless.
>>
>> The question is why isn't there some kind of identifier on table 1 that
>> gives you some idea of what the id/table record is for?
>>
>
> Exactly the id_table1 FK has no context, it is just a number generator, so
> why make it separate? If want to just generate numbers why not just use the
> sequence directly?
>
>
>> David J.
>>
>>
>>
>
>
> --
> Adrian Klaver
> adrian(dot)klaver(at)gmail(dot)com
>
>
>
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