On 04/20/2016 11:21 PM, Cecil Westerhof wrote: > 2016-04-20 18:07 GMT+02:00 R Smith <rsmith at rsweb.co.za>: > >> >> On 2016/04/20 6:04 PM, Cecil Westerhof wrote: >> >>> I am thinking about creating a table where a certain field will be a >>> description, or a key to the description. Would it be possible to have a >>> constraint on this field that it is an id, that this id points to an >>> existing record in a description table? >>> >>> >> https://www.sqlite.org/foreignkeys.html > > ?If I read that correctly then a field has to be NULL or point to a record > in the other table. I want it to point to a record if it is an INT and whem > it is TEXT it is just the text. (And it should only be allowed to be an INT > or TEXT.)
I don't think you can use a constraint in SQLite for that. You could write a trigger to check that only valid values are inserted into the table though (and the corresponding trigger for updates, and for updates and deletes on the referenced table). Dan. > ? > > -- > Cecil Westerhof > _______________________________________________ > sqlite-users mailing list > sqlite-users at mailinglists.sqlite.org > http://mailinglists.sqlite.org/cgi-bin/mailman/listinfo/sqlite-users
