user_drug.user_id
is constrained by Foreign Key drug.id
(which is a Primary Key).
Table structure is as follows:
user
id name income
1 Foo 10000
2 Bar 20000
3 Baz 30000
drug
id name
0 Marijuana
1 Cocaine
2 Heroin
user_drug
user_id drug_id
1 1
1 2
2 1
2 3
3 3
Are there any drawbacks to starting drug.id
at 0? I have a feeling that that will make things more natural with PHP since arrays also start at 0, but I want to make sure there aren't any drawbacks with using '0' for an id (e.g. it might be interpreted as null or some other strange potential occurrence/conflict).