Multiple inner joins in a query - sql

Question

Players{
Pid int primary key,
tid int not null references Teams,
name text not null,
age int not null
}
Teams{
tid int primary key,
name text not null,
location not null
}
Possessions{
id int primary key,
pid int not null references Players,
time int not null, //the time the possession started for a player
held int not null //for how much time he had the ball
}
I would like to create a view called Teampasses where I can select (passer,passee) as follows:Passer and passe must be from the same team and passes possession starting time equals to passes possession starting time +held (time he has the ball). What I have done so far is this:
SELECT x.name AS passer,y.name as Pasee
FROM player x
INNER JOIN player y ON x.tid=y.tid
INNER JOIN possesions p ON p.pid=x.pid AND p.pid=y.pid AND ...
in the ... section right of AND i would like to do something like x.time+x.held=y.time.How could i refer to there two?

Answer 1

I see an issue with your data:
Your Possessions table only has a single foreign key to the Players table for the passer. It needs to also include the Pid of the Passee. Otherwise, there's no way to filter out which player on the passer team is the Passee for a given Possession.
I would suggest changing the Possessions table as follows:
Possessions(
id int primary key,
pid_passer int not null references Players,
pid_passee int not null references Players,
time int not null, //the time the possession started for a player
held int not null //for how much time he had the ball
)
With this change, your data will work and the query becomes trivial.