Q: Does foreign keys affect NATURAL JOINs?

 

SQLite 3.6.18 sample (NO foreign keys):

CREATE TABLE t1 (a INTEGER PRIMARY KEY, b INTEGER NOT NULL);

CREATE TABLE t2 (x INTEGER PRIMARY KEY, y INTEGER NOT NULL);

SELECT * FROM a NATURAL JOIN b; -- Cartesian product!

 

SQLite 3.6.19 sample (using foreign keys):

CREATE TABLE t1 (a INTEGER PRIMARY KEY, b INTEGER NOT NULL);

CREATE TABLE t2 (x INTEGER PRIMARY KEY, FOREIGN KEY(y) REFERENCES t1(a) );

 

SELECT * FROM a NATURAL JOIN b; -- Inner join??

 

I haven't tested this. Does this NATURAL JOIN produce an inner join or a 
cartesian product?

 

 

Anyway, I think this should be documented.
                                          
_________________________________________________________________
Hitta hetaste singlarna på MSN Dejting!
http://dejting.se.msn.com/channel/index.aspx?trackingid=1002952
_______________________________________________
sqlite-users mailing list
sqlite-users@sqlite.org
http://sqlite.org:8080/cgi-bin/mailman/listinfo/sqlite-users

Reply via email to