Welcome to the Treehouse Community

The Treehouse Community is a meeting place for developers, designers, and programmers of all backgrounds and skill levels to get support. Collaborate here on code errors or bugs that you need feedback on, or asking for an extra set of eyes on your latest project. Join thousands of Treehouse students and alumni in the community today. (Note: Only Treehouse students can comment or ask questions, but non-students are welcome to browse our conversations.)

Looking to learn something new?

Treehouse offers a seven day free trial for new students. Get access to thousands of hours of content and a supportive community. Start your free trial today.

Development Tools Database Foundations Joining Relational Data Between Tables in SQL Keys and Auto-Incrementing Values

Binu Alexander
Binu Alexander
4,081 Points

Stuck at the alter table statement

Task

Alter the "t_movies" table to add a foreign key called "fk_genre_id" and constrain it to reference the "t_genres" "pk_id".

my code

alter table t_movies add constraint foreign key(fk_genre_id) references t_genres(pk_id)

What is wrong with my statement ?

2 Answers

Piotrek Smyda
Piotrek Smyda
3,786 Points

Hey,

You need to add new column for foreign key.

Your statement should be like this:

alter table t_movies add column fk_genre_id integer null, add constraint foreign key (fk_genre_id) references t_genres(pk_id)
Sobin Sebastian
Sobin Sebastian
5,348 Points

alter table t_movies add column fk_genre_id integer null, add constraint foreign key (fk_genre_id) references t_genres(pk_id);