I've got a database designed like:
t_relationships
t_actor
The relationship table has many actors with one relationship_uuid
.
I'm having problems with efficient query that will give me all the actors in a relationship with a given actor.
For instance, if actor table
have entries [1,1,cat], [2,2,dog], [3,3,tree], [4,4,box]
and relationship
has [1,1,1], [2,1,2], [3,1,3], [4,2,1] [5,2,4], [6,3,2], [7,3,4]
.
What's the best way to find out who is in a relationship with a cat?
You don't need the id
columns. You can just drop them. A join is what you are looking for
select ar.name
from t_actor a
join t_relationships r on r.actor_uuid = a.actor_uuid
join t_actor ar on ar.actor_uuid = r.relationship_uuid
where a.name = 'cat'
The technical post webpages of this site follow the CC BY-SA 4.0 protocol. If you need to reprint, please indicate the site URL or the original address.Any question please contact:yoyou2525@163.com.