Related to my previous question https://www.mail-archive.com/sqlite-users@mailinglists.sqlite.org/msg107527.html, I want to prevent the client from inserting a cycle.
For example - sqlite> .sch edges CREATE TABLE edges(parent integer not null, child integer not null, constraint self_reference check (parent<>child)); sqlite> select * from edges; parent child 1 2 1 3 2 4 insert into edges select 2, 5; -- ok insert into edges select 2, 1; -- should not be allowed. insert into edges select 4, 1; -- should not be allowed. Many kinds of insertions can be prevented using triggers. Existing cycles can be detected using a recurisve common table expression. However, since CTEs are not supported inside triggers, I assume they can't be used for this purpose. Is there another way? _______________________________________________ sqlite-users mailing list sqlite-users@mailinglists.sqlite.org http://mailinglists.sqlite.org/cgi-bin/mailman/listinfo/sqlite-users
