sql - Adding constraint to several tables -


if have following tables:

user(user_id, name)  job(job_id,...)  authorised(job_id,user_id) //a job authorised done 1 or more users  work(user_id, job_id) //user working on job

the question is: work table want have constraint saying entries, user should authorised work on job. possible (as needs @ authroised table well?

you can foreign key relationship.

create unique index unq_authorised_job_user on authorized(job_id, user_id);

(this needed if combination not primary key or unique.).

alter table work add constraint foreign key (job_id, user_id) references authorised(job_id, user_id)

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