arangosh> db._create("mycollection")
[ArangoCollection 6609, "mycollection" (type document, status loaded)]
arangosh> db.mycollection.save({ _key: "testKey", Hello : "World" })
{
"_id" : "mycollection/testKey",
"_key" : "testKey",
"_rev" : "6612"
}
arangosh> db._query('FOR my IN mycollection RETURN my._key').toArray()
[
"testKey"
]