how to fetch data from two collection in arangodb - arangodb

Question

my project backend is arangodb. I have two collections named "test" and "demo". i need to fetch data from both these tables. my data is like this:
test
[
{
"firstName": "abc",
"lastName": "pqr",
"company": "abc Industries",
"id": "1234"
},
{
"firstName": "xyz",
"lastName": "qwe",
"company": "xyz Industries",
"id": "5678"
}
]
demo
[
{
"clientId": "1234",
"subject": "test",
"message": "testing",
"priority": "High",
"status": "closed",
"id": "111111"
},
{
"clientId": "1234",
"subject": "hiii",
"message": "demo",
"priority": "High",
"status": "closed",
"id": "222222"
},
]
in this id of the test is same as clientid of the demo. i need to select data from the table that is data of the client "1234". how can i implement this using AQL(arango query language). i am new to arango. any suggestion will highly appreciable.

Answer 1

You can do this with joins or subqueries.
A solution with a subqueries would look like:
FOR t IN test
FILTER t.id == #client
RETURN {
test: t,
demo: (FOR d IN demo
FILTER d.clientId == #client
RETURN d)
}
The #client is a bind parameter which contains your value 1234.
The result is:
[
{
"test": {
"_key": "140306",
"_id": "test/140306",
"_rev": "_Urbgapq---",
"company": "abc Industries",
"firstName": "abc",
"id": "1234",
"lastName": "pqr"
},
"demo": [
{
"_key": "140233",
"_id": "demo/140233",
"_rev": "_UrbfyAm---",
"clientId": "1234",
"id": "222222",
"message": "demo",
"priority": "High",
"status": "closed",
"subject": "hiii"
},
{
"_key": "140200",
"_id": "demo/140200",
"_rev": "_UrbfjfG---",
"clientId": "1234",
"id": "111111",
"message": "testing",
"priority": "High",
"status": "closed",
"subject": "test"
}
]
}
]

Answer 2

For t in test
for d in demo
filter t.id == d.clientId
filter t.id == #client
return {t,d}

Answer 3

FOR collection IN [test,demo]
FOR x IN collection
RETURN x