create database mydb0;
use mydb0;
create table parent (
a int primary key,
b int not null,
c int not null,
unique(b) using hash,
index(c)) engine = ndb;
create database mydb1;
use mydb1;
create table child (
a int primary key,
b int not null,
c int not null,
constraint fk1 foreign key(a) references mydb0.parent (a),
unique(b) using hash,
index(c)) engine = ndb;
show create table child;
Table	Create Table
child	CREATE TABLE `child` (
  `a` int(11) NOT NULL,
  `b` int(11) NOT NULL,
  `c` int(11) NOT NULL,
  PRIMARY KEY (`a`),
  UNIQUE KEY `b` (`b`) USING HASH,
  KEY `c` (`c`),
  CONSTRAINT `fk1` FOREIGN KEY (`a`) REFERENCES `mydb0`.`parent` (`a`) ON DELETE NO ACTION ON UPDATE NO ACTION
) ENGINE=ndbcluster DEFAULT CHARSET=utf8mb4 COLLATE=utf8mb4_0900_ai_ci
alter table child algorithm=copy, add constraint fk2 foreign key (b)
references mydb0.parent(a);
show create table child;
Table	Create Table
child	CREATE TABLE `child` (
  `a` int(11) NOT NULL,
  `b` int(11) NOT NULL,
  `c` int(11) NOT NULL,
  PRIMARY KEY (`a`),
  UNIQUE KEY `b` (`b`) USING HASH,
  KEY `c` (`c`),
  CONSTRAINT `fk1` FOREIGN KEY (`a`) REFERENCES `mydb0`.`parent` (`a`) ON DELETE NO ACTION ON UPDATE NO ACTION,
  CONSTRAINT `fk2` FOREIGN KEY (`b`) REFERENCES `mydb0`.`parent` (`a`) ON DELETE NO ACTION ON UPDATE NO ACTION
) ENGINE=ndbcluster DEFAULT CHARSET=utf8mb4 COLLATE=utf8mb4_0900_ai_ci
alter table child algorithm=inplace, add constraint fk3 foreign key (c)
references mydb0.parent(a);
show create table child;
Table	Create Table
child	CREATE TABLE `child` (
  `a` int(11) NOT NULL,
  `b` int(11) NOT NULL,
  `c` int(11) NOT NULL,
  PRIMARY KEY (`a`),
  UNIQUE KEY `b` (`b`) USING HASH,
  KEY `c` (`c`),
  CONSTRAINT `fk1` FOREIGN KEY (`a`) REFERENCES `mydb0`.`parent` (`a`) ON DELETE NO ACTION ON UPDATE NO ACTION,
  CONSTRAINT `fk2` FOREIGN KEY (`b`) REFERENCES `mydb0`.`parent` (`a`) ON DELETE NO ACTION ON UPDATE NO ACTION,
  CONSTRAINT `fk3` FOREIGN KEY (`c`) REFERENCES `mydb0`.`parent` (`a`) ON DELETE NO ACTION ON UPDATE NO ACTION
) ENGINE=ndbcluster DEFAULT CHARSET=utf8mb4 COLLATE=utf8mb4_0900_ai_ci
alter table child algorithm=copy, drop foreign key fk2;
show create table child;
Table	Create Table
child	CREATE TABLE `child` (
  `a` int(11) NOT NULL,
  `b` int(11) NOT NULL,
  `c` int(11) NOT NULL,
  PRIMARY KEY (`a`),
  UNIQUE KEY `b` (`b`) USING HASH,
  KEY `c` (`c`),
  CONSTRAINT `fk1` FOREIGN KEY (`a`) REFERENCES `mydb0`.`parent` (`a`) ON DELETE NO ACTION ON UPDATE NO ACTION,
  CONSTRAINT `fk3` FOREIGN KEY (`c`) REFERENCES `mydb0`.`parent` (`a`) ON DELETE NO ACTION ON UPDATE NO ACTION
) ENGINE=ndbcluster DEFAULT CHARSET=utf8mb4 COLLATE=utf8mb4_0900_ai_ci
alter table child algorithm=inplace, drop foreign key fk3;
show create table child;
Table	Create Table
child	CREATE TABLE `child` (
  `a` int(11) NOT NULL,
  `b` int(11) NOT NULL,
  `c` int(11) NOT NULL,
  PRIMARY KEY (`a`),
  UNIQUE KEY `b` (`b`) USING HASH,
  KEY `c` (`c`),
  CONSTRAINT `fk1` FOREIGN KEY (`a`) REFERENCES `mydb0`.`parent` (`a`) ON DELETE NO ACTION ON UPDATE NO ACTION
) ENGINE=ndbcluster DEFAULT CHARSET=utf8mb4 COLLATE=utf8mb4_0900_ai_ci
alter table mydb0.parent algorithm=copy, rename mydb1.parent;
show create table child;
Table	Create Table
child	CREATE TABLE `child` (
  `a` int(11) NOT NULL,
  `b` int(11) NOT NULL,
  `c` int(11) NOT NULL,
  PRIMARY KEY (`a`),
  UNIQUE KEY `b` (`b`) USING HASH,
  KEY `c` (`c`),
  CONSTRAINT `fk1` FOREIGN KEY (`a`) REFERENCES `parent` (`a`) ON DELETE NO ACTION ON UPDATE NO ACTION
) ENGINE=ndbcluster DEFAULT CHARSET=utf8mb4 COLLATE=utf8mb4_0900_ai_ci
alter table mydb1.parent algorithm=inplace, rename mydb0.parent;
show create table child;
Table	Create Table
child	CREATE TABLE `child` (
  `a` int(11) NOT NULL,
  `b` int(11) NOT NULL,
  `c` int(11) NOT NULL,
  PRIMARY KEY (`a`),
  UNIQUE KEY `b` (`b`) USING HASH,
  KEY `c` (`c`),
  CONSTRAINT `fk1` FOREIGN KEY (`a`) REFERENCES `mydb0`.`parent` (`a`) ON DELETE NO ACTION ON UPDATE NO ACTION
) ENGINE=ndbcluster DEFAULT CHARSET=utf8mb4 COLLATE=utf8mb4_0900_ai_ci
use test;
alter table mydb1.child algorithm=copy, add constraint fk2 foreign key (b)
references mydb0.parent(a);
use mydb1;
show create table child;
Table	Create Table
child	CREATE TABLE `child` (
  `a` int(11) NOT NULL,
  `b` int(11) NOT NULL,
  `c` int(11) NOT NULL,
  PRIMARY KEY (`a`),
  UNIQUE KEY `b` (`b`) USING HASH,
  KEY `c` (`c`),
  CONSTRAINT `fk1` FOREIGN KEY (`a`) REFERENCES `mydb0`.`parent` (`a`) ON DELETE NO ACTION ON UPDATE NO ACTION,
  CONSTRAINT `fk2` FOREIGN KEY (`b`) REFERENCES `mydb0`.`parent` (`a`) ON DELETE NO ACTION ON UPDATE NO ACTION
) ENGINE=ndbcluster DEFAULT CHARSET=utf8mb4 COLLATE=utf8mb4_0900_ai_ci
use test;
alter table mydb1.child algorithm=inplace, add constraint fk3 foreign key (c)
references mydb0.parent(a);
use mydb1;
show create table child;
Table	Create Table
child	CREATE TABLE `child` (
  `a` int(11) NOT NULL,
  `b` int(11) NOT NULL,
  `c` int(11) NOT NULL,
  PRIMARY KEY (`a`),
  UNIQUE KEY `b` (`b`) USING HASH,
  KEY `c` (`c`),
  CONSTRAINT `fk1` FOREIGN KEY (`a`) REFERENCES `mydb0`.`parent` (`a`) ON DELETE NO ACTION ON UPDATE NO ACTION,
  CONSTRAINT `fk2` FOREIGN KEY (`b`) REFERENCES `mydb0`.`parent` (`a`) ON DELETE NO ACTION ON UPDATE NO ACTION,
  CONSTRAINT `fk3` FOREIGN KEY (`c`) REFERENCES `mydb0`.`parent` (`a`) ON DELETE NO ACTION ON UPDATE NO ACTION
) ENGINE=ndbcluster DEFAULT CHARSET=utf8mb4 COLLATE=utf8mb4_0900_ai_ci
use test;
drop database mydb1;
drop database mydb0;
set @i=2;
create database mydb0;
use mydb0;
create table t0 (a int primary key) engine = innodb;
create table t1 (a int primary key) engine = innodb;
alter table mydb0.t0 add constraint fk0 foreign key (a)
references mydb0.t1(a);
alter table mydb0.t1 add constraint fk1 foreign key (a)
references mydb0.t0(a);
drop database mydb0;
set @i=1;
create database mydb0;
use mydb0;
create table t0 (a int primary key) engine = ndb;
create table t1 (a int primary key) engine = ndb;
alter table mydb0.t0 add constraint fk0 foreign key (a)
references mydb0.t1(a);
alter table mydb0.t1 add constraint fk1 foreign key (a)
references mydb0.t0(a);
drop database mydb0;
set @i=2;
create database mydb0;
use mydb0;
create table t0 (a int primary key) engine = innodb;
create database mydb1;
use mydb1;
create table t1 (a int primary key) engine = innodb;
alter table mydb0.t0 add constraint fk0 foreign key (a)
references mydb1.t1(a);
alter table mydb1.t1 add constraint fk1 foreign key (a)
references mydb0.t0(a);
drop database mydb0;
ERROR HY000: Cannot drop table 't0' referenced by a foreign key constraint 'fk1' on table 't1'.
drop database mydb1;
ERROR HY000: Cannot drop table 't1' referenced by a foreign key constraint 'fk0' on table 't0'.
alter table mydb0.t0 drop foreign key fk0;
drop database mydb0;
ERROR HY000: Cannot drop table 't0' referenced by a foreign key constraint 'fk1' on table 't1'.
drop database mydb1;
drop database mydb0;
set @i=1;
create database mydb0;
use mydb0;
create table t0 (a int primary key) engine = ndb;
create database mydb1;
use mydb1;
create table t1 (a int primary key) engine = ndb;
alter table mydb0.t0 add constraint fk0 foreign key (a)
references mydb1.t1(a);
alter table mydb1.t1 add constraint fk1 foreign key (a)
references mydb0.t0(a);
drop database mydb0;
ERROR HY000: Cannot drop table 't0' referenced by a foreign key constraint 'fk1' on table 't1'.
drop database mydb1;
ERROR HY000: Cannot drop table 't1' referenced by a foreign key constraint 'fk0' on table 't0'.
alter table mydb0.t0 drop foreign key fk0;
drop database mydb0;
ERROR HY000: Cannot drop table 't0' referenced by a foreign key constraint 'fk1' on table 't1'.
drop database mydb1;
drop database mydb0;