create foreign key (MariaDB) - read manuals still not working

[roberto68]

I need to create a foregin key in table pictures that references id from table locations - locations.id - I chcek mariaDB manuals https://mariadb.com/kb/en/mariadb/foreign-keys/ but it says I have error in my syntax still here's my code

alter table pictures(add column location_id int not null, foreign key(location_id) references locations (id) on delete cascade on update restrict)

what am I doing wrong? and one more question : how to create index in MariaDB cause I haven't been successfull in that too, thanks

[justsomeguy]

You shouldn't have parentheses after the table name in ALTER TABLE. e.g.:alter table pictures add column...

[roberto68]

thanks actually there should be parnenthesis but after add column, unlike I get an error

alter table pictures add column (location_id int not null, foreign key(location_id) references locations (id) on delete cascade on update restrict);