Re: Advice on a table structure
| От | David G. Johnston |
|---|---|
| Тема | Re: Advice on a table structure |
| Дата | |
| Msg-id | CAKFQuwZeqSY8fEyRKSqbe=5pkMQcyFwQbtfiEXRHERR2TsekQA@mail.gmail.com обсуждение исходный текст |
| Ответ на | Advice on a table structure (JORGE MALDONADO <jorgemal1960@gmail.com>) |
| Список | pgsql-novice |
On Monday, April 27, 2020, JORGE MALDONADO <jorgemal1960@gmail.com> wrote:
---------------------------COUPLES TABLE---------------------------* Id* Husband (represents an Id of PERSONS table)* Wife ( represents an Id of PERSONS table)One restriction is that one person cannot have more than one spouse.I also thought about adding a field to the PERSONS table specifying his/her spouse but it seems to me that this approach represents a kind of "circular" relation between 2 records.I am writing to ask for advice about an optimal approach to model this situation.
What criteria are you trying to optimize?
Regardless, in SQL its generally safe to add a table when you want to model a relationship between two entities. You mainly trade flexibility for ease of use. In this case writing a custom set of triggers to ensure whatever constraints you want are kept during data change. Or at least that the entry for the husband column must be a male person which you can then combine with a unique index. And change those rules when you realize the world isn’t so binary.
David J.
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