Re: table referencing several others
От | PFC |
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Тема | Re: table referencing several others |
Дата | |
Msg-id | op.ts1etec1cigqcu@apollo13 обсуждение исходный текст |
Ответ на | table referencing several others (Louis-David Mitterrand <vindex+lists-pgsql-general@apartia.org>) |
Список | pgsql-general |
Here what I would do : - Have a table "objects", which contains locations, shows, persons, well anything you want to relate to the forums in question. - Simply add an object_id to your forums table. Now, how do you distinguish between different types of objects in your objects table ? You can add an object_type field and teach your object-relational mapper that it expresses the class of object that should be instantiated when fetching the rows. You can have fields that are only used by some types of objects, and null for others. You can use table inheritance. You can also have an objects table, and tables locations_extra_infos, people_extra_info which store the fields that are unique to each type of object. > - every subsequent message of the thread will carry these useless fields > (only the first message in thread uses one of them), If the fields are set to NULL, they will only use one bit, so this is not a problem. Do not store the location_id in each message of the thread : if you want to change it, you'll have to update all the messages !
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