how to join collections in faunadb? - faunadb

Question

I want to get nested ref's value within the query I'm executing, but by default response is returning the ref of other collection. consider this minimum example; here are user and coin models, within "users" and "coins" collections
user { // ref: 123456
name: foo
location: bar
}
coin { // ref: 124457
amount: 5457
awardedTo: Ref(Collection("users"), "123456")
}
when I run this query
q.Get(q.Ref(q.Collection("coins"), "124457"))
the response is something like this:
{
data: {
amount: 5457,
awardedTo: #ref: {id: "123456", collection: {…}}
},
ref: #ref: {id: "124457", collection: {…}},
ts: 1622547855525255
}
But how is it possible to get nested user's value in the same query to have a response like this:
{
data: {
amount: 5457,
awardedTo: {
name: foo,
location: bar
}
},
ref: #ref: {id: "124457", collection: {…}},
ts: 1622547855525255
}
I have read Join's documentation but it wasn't helpful in this case, and also tried this way, but it didn't work either:
q.Let({
coin: q.Get(q.Ref(q.Collection("coins"), '124457'))
},
q.Union(
q.Get(q.Select(["data","awaredTo"], q.Var("coin"))),
q.Var("coins")
)
)

Answer 1

you can use this FQL:
Let(
{
coin: Select(['data'],Get(Ref(Collection("coin"), "1"))),
user: Select(['data'],Get(Select(['awardedTo'],Var('coin'))))
},
Merge(Var('coin'),{awardedTo:Var('user')})
)
It retrieves data from coin, extracts the user ref and merge all together.
Luigi