Понедельник, 13 мая 2013, 17:03 +01:00 от Simon Davies <simon.james.dav...@gmail.com>: >On 13 May 2013 16:52, Simon Slavin < slav...@bigfraud.org > wrote: >> >> On 13 May 2013, at 3:54pm, Григорий Григоренко < grigore...@mail.ru > wrote: >> >>> sample database is: >>> >>> PRAGMA FOREIGN_KEYS=1; >>> CREATE TABLE cat(id INTEGER PRIMARY KEY, name); >>> INSERT INTO cat VALUES (1, 'Alice'); >>> CREATE TABLE owner(pet INTEGER REFERENCES cat(id)); >>> INSERT INTO owner VALUES(1); >>> >>> This script fails to drop tables with 'foreign key constraint failed': >>> >>> SAVEPOINT edit; >>> PRAGMA FOREIGN_KEYS=0; >>> DROP TABLE cat; >>> DROP TABLE owner; >>> RELEASE edit; >>> PRAGMA FOREIGN_KEYS=1; >> >> You are DROPping your tables in the wrong order. The 'owner' table refers >> to the 'cat' table. If you DROP 'cat' you would be left with an 'owner' >> table which refers to a table which doesn't exist. Swap the order of the >> DROPs and your database will not risk that kind of disaster. >> >>> This script works OK: >>> >>> PRAGMA FOREIGN_KEYS=0; >>> DROP TABLE cat; >>> DROP TABLE owner; >>> PRAGMA FOREIGN_KEYS=1; >> >> Your problem with the one with SAVEPOINT is that SQLite doesn't know when >> you're going to do the RELEASE. If you left out the second DROP, then >> issued a RELEASE, the database would be corrupt, so SQLite issues the error >> message to warn you about it. The version without the SAVEPOINT never has >> to worry about you doing that. >> >> Simon. > >http://www.sqlite.org/pragma.html#pragma_foreign_keys : > >"...foreign key constraint enforcement may only be enabled or disabled >when there is no pending BEGIN or SAVEPOINT. "
Ups. My fault, must have read docs more carefully. Thank you. > >Regards, >Simon >_______________________________________________ >sqlite-users mailing list >sqlite-users@sqlite.org >http://sqlite.org:8080/cgi-bin/mailman/listinfo/sqlite-users _______________________________________________ sqlite-users mailing list sqlite-users@sqlite.org http://sqlite.org:8080/cgi-bin/mailman/listinfo/sqlite-users
