Attempting to use this example to join on an array of IDs: https://github.com/rethinkdb/rethinkdb/issues/1533#issuecomment-26112118
Stores table snippet
{
"storeID": "80362c86-94cc-4be3-b2b0-2607901804dd",
"locations": [
"5fa96762-f0a9-41f2-a6c1-1335185f193d",
"80362c86-94cc-4be3-b2b0-2607901804dd"
]
}
Locations table snippet
{
"lat": 125.231345,
"lng": 44.23123,
"id": "80362c86-94cc-4be3-b2b0-2607901804dd"
}
I'd like to select the stores and join their store locations.
Original example from ReThinkDB contributor:
r.table("blog_posts")
.concat_map(lambda x: x["comment_ids"].map(lambda y: x.merge("comment_id" : y)))
.eq_join("comment_id", r.table("comments"))
My attempt to convert to JS
r.table("stores")
.concatMap((function(x){
return x("locations").map((function(y){
return x("locations").add(y);
}))
}))
.eqJoin("locations", r.table("locations"))
Result
RqlRuntimeError: Expected type ARRAY but found STRING
You're using concatMap incorrectly, here's what you want the first part of your query to be.
r.table("stores")
.concatMap(function (x) {
return x("locations");
})
Try running that, it should give you:
["5fa96762-...", "80362c86-...", ...]
Now we need to join this to the other table. To join an array of ids to a table you can use eqjoin like so:
array.eqJoin(function (row) { return row; }, table)
There's more details here: rql get multple documents from list of keys rethinkdb in javascript.
Putting it all together we get:
r.table("stores")
.concatMap(function (x) {
return x("locations")
})
.eqJoin(function (i) { return i; }, r.table("locations"))
To get back the documents from the stores:
r.table("stores")
.concatMap(function (x) {
return x("locations").map(function (loc) {
return x.merge({locations: loc});
});
})
.eqJoin("locations", r.table("locations"))
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