# Create statement with FK on base column of stored column create table t1(f1 int, f2 int as(f1) stored, foreign key(f1) references t2(f1) on delete cascade)engine=innodb; ERROR HY000: Can't create table `test`.`t1` (errno: 150 "Foreign key constraint is incorrectly formed") # adding new stored column during alter table copy operation. create table t1(f1 int primary key) engine=innodb; create table t2(f1 int not null, f2 int as (f1) virtual, foreign key(f1) references t1(f1) on update cascade)engine=innodb; alter table t2 add column f3 int as (f1) stored, add column f4 int as (f1) virtual; show create table t2; Table Create Table t2 CREATE TABLE `t2` ( `f1` int(11) NOT NULL, `f2` int(11) GENERATED ALWAYS AS (`f1`) VIRTUAL, `f3` int(11) GENERATED ALWAYS AS (`f1`) STORED, `f4` int(11) GENERATED ALWAYS AS (`f1`) VIRTUAL, KEY `f1` (`f1`), CONSTRAINT `t2_ibfk_1` FOREIGN KEY (`f1`) REFERENCES `t1` (`f1`) ON UPDATE CASCADE ) ENGINE=InnoDB DEFAULT CHARSET=latin1 drop table t2; # adding foreign key constraint for base columns during alter copy. create table t2(f1 int not null, f2 int as (f1) stored) engine=innodb; alter table t2 add foreign key(f1) references t1(f1) on update cascade, algorithm=copy; show create table t2; Table Create Table t2 CREATE TABLE `t2` ( `f1` int(11) NOT NULL, `f2` int(11) GENERATED ALWAYS AS (`f1`) STORED, KEY `f1` (`f1`), CONSTRAINT `t2_ibfk_1` FOREIGN KEY (`f1`) REFERENCES `t1` (`f1`) ON UPDATE CASCADE ) ENGINE=InnoDB DEFAULT CHARSET=latin1 drop table t2; # adding foreign key constraint for base columns during online alter. create table t2(f1 int not null, f2 int as (f1) stored) engine=innodb; set foreign_key_checks = 0; alter table t2 add foreign key(f1) references t1(f1) on update cascade, algorithm=inplace; ERROR 0A000: Cannot add foreign key on the base column of stored column drop table t2; # adding stored column via online alter. create table t2(f1 int not null, foreign key(f1) references t1(f1) on update cascade)engine=innodb; alter table t2 add column f2 int as (f1) stored, algorithm=inplace; ERROR 0A000: ALGORITHM=INPLACE is not supported for this operation. Try ALGORITHM=COPY drop table t2, t1; # # BUG#26731689 FK ON TABLE WITH GENERATED COLS: ASSERTION POS < N_DEF # CREATE TABLE s (a INT, b INT GENERATED ALWAYS AS (0) STORED, c INT, d INT GENERATED ALWAYS AS (0) VIRTUAL, e INT) ENGINE=innodb; CREATE TABLE t (a INT) ENGINE=innodb; ALTER TABLE s ADD CONSTRAINT c FOREIGN KEY (e) REFERENCES t(a) ON UPDATE SET null; ERROR HY000: Failed to add the foreign key constaint. Missing index for constraint 'c' in the referenced table 't' ALTER TABLE t ADD PRIMARY KEY(a); ALTER TABLE s ADD CONSTRAINT c FOREIGN KEY (e) REFERENCES t(a) ON UPDATE SET null; DROP TABLE s,t; CREATE TABLE s (a INT GENERATED ALWAYS AS (0) VIRTUAL, b INT GENERATED ALWAYS AS (0) STORED, c INT) ENGINE=innodb; CREATE TABLE t (a INT) ENGINE=innodb; ALTER TABLE s ADD CONSTRAINT c FOREIGN KEY (c) REFERENCES t(a) ON UPDATE SET null; ERROR HY000: Failed to add the foreign key constaint. Missing index for constraint 'c' in the referenced table 't' ALTER TABLE t ADD PRIMARY KEY(a); ALTER TABLE s ADD CONSTRAINT c FOREIGN KEY (c) REFERENCES t(a) ON UPDATE SET null; DROP TABLE s,t; CREATE TABLE s (a INT, b INT GENERATED ALWAYS AS (0) STORED) ENGINE=innodb; CREATE TABLE t (a INT PRIMARY KEY) ENGINE=innodb; ALTER TABLE s ADD CONSTRAINT c FOREIGN KEY (a) REFERENCES t(a) ON UPDATE SET null; DROP TABLE s,t; CREATE TABLE s (a INT, b INT) ENGINE=innodb; CREATE TABLE t (a INT) ENGINE=innodb; ALTER TABLE s ADD CONSTRAINT c FOREIGN KEY (a) REFERENCES t(a) ON UPDATE SET null; ERROR HY000: Failed to add the foreign key constaint. Missing index for constraint 'c' in the referenced table 't' ALTER TABLE t ADD PRIMARY KEY(a); ALTER TABLE s ADD CONSTRAINT c FOREIGN KEY (a) REFERENCES t(a) ON UPDATE SET null; DROP TABLE s,t;