Multiple foreign keys
Stel je hebt :
tabel 1 users
id
naam
tabel 2 files
id
lokatie
tabel 3 shared_files
id
userid
shared_user_id
file_id
En dan deze query bij de te tabel shared_files:
Code (php)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
2
3
4
5
6
7
8
9
10
11
12
13
14
15
ALTER TABLE shared_files
ADD CONSTRAINT fk_shared_files_1
FOREIGN KEY (userid)
REFERENCES users (id)
ON DELETE CASCADE
TABLE shared_files
ADD CONSTRAINT fk_shared_files_2
FOREIGN KEY (shared_userid)
REFERENCES users (id)
ON DELETE CASCADE
TABLE shared_files
ADD CONSTRAINT fk_shared_files_3
FOREIGN KEY (file_id)
REFERENCES files (id)
ON DELETE CASCADE;
ADD CONSTRAINT fk_shared_files_1
FOREIGN KEY (userid)
REFERENCES users (id)
ON DELETE CASCADE
TABLE shared_files
ADD CONSTRAINT fk_shared_files_2
FOREIGN KEY (shared_userid)
REFERENCES users (id)
ON DELETE CASCADE
TABLE shared_files
ADD CONSTRAINT fk_shared_files_3
FOREIGN KEY (file_id)
REFERENCES files (id)
ON DELETE CASCADE;
Is dit mogelijk / correct?
Gr, RT.
Gewijzigd op 01/01/1970 01:00:00 door RT
Gesponsorde koppelingen:
