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. _______________________________________________ sqlite-users mailing list sqlite-users@sqlite.org http://sqlite.org:8080/cgi-bin/mailman/listinfo/sqlite-users
