23 lines
1.3 KiB
Plaintext
23 lines
1.3 KiB
Plaintext
create table counties (
|
|
county varchar(30) not null primary key,
|
|
country varchar(30)
|
|
) engine=ndb;
|
|
insert into counties values ('Berkshire','England'),('Shropshire','England'),
|
|
('Oxfordshire','England'),('Buckinghamshire','England'),('Somewhere','Earth');
|
|
create table towns (
|
|
town varchar(30) not null primary key,
|
|
county varchar(30) default "Somewhere",
|
|
index county_county_index (county),
|
|
constraint county_town foreign key (county)
|
|
references counties(county) on delete set default on update restrict
|
|
) engine=ndb;
|
|
insert into towns values ('Maidenhead','Berkshire'),('Reading','Berkshire'),
|
|
('Shrewsbury','Shropshire'),('Oxford','Oxfordshire');
|
|
delete from counties where county='Shropshire';
|
|
ERROR 23000: Cannot delete or update a parent row: a foreign key constraint fails (`test`.`towns`, CONSTRAINT `county_town` FOREIGN KEY (`county`) REFERENCES `counties` (`county`) ON DELETE SET DEFAULT ON UPDATE RESTRICT)
|
|
show warnings;
|
|
Level Code Message
|
|
Warning 1296 Got error 256 'Foreign key constraint violated: Referenced row exists' from NDB
|
|
Error 1451 Cannot delete or update a parent row: a foreign key constraint fails (`test`.`towns`, CONSTRAINT `county_town` FOREIGN KEY (`county`) REFERENCES `counties` (`county`) ON DELETE SET DEFAULT ON UPDATE RESTRICT)
|
|
drop table towns, counties;
|