2012/3/9 Christoph P.U. Kukulies <k...@kukulies.org>:
CREATE TABLE instance (
path TEXT,
basename TEXT,
size INT,
md5sum TEXT,
creation_date TEXT,
last_write_time TEXT,
FOREIGN KEY (md5sum) REFERENCES resource (md5sum)
);
CREATE TABLE resource (
md5sum TEXT,
data BLOB,
primary key(md5sum)
);
> What makes the contents of two files equal (so that their contents can be
> represented by the same resource) ?
md5sum = md5sum
> My problem: what do I have to change in TABLE instance so that I can use it
> to determine whether the key is already
> in the resource TABLE?
- Make new md5sum from new data
INSERT OR IGNORE INTO resource ...
INSERT OR REPLACE INTO instance ...
> Would that be a FOREIGN KEY? And how would I do that in syntax?
> If I need FOREIGN KEY, would I have to enable that in SQLite somehow (at
> compile time)?
> Thanks,
> Christoph
PRAGMA foreign_keys = ON;
in runtime. But you don't need foreign keys support in this case. You
may use it for garbage collection.
--
Kit
_______________________________________________
sqlite-users mailing list
sqlite-users@sqlite.org
http://sqlite.org:8080/cgi-bin/mailman/listinfo/sqlite-users
