Rethinkdb docs has this example to improve getAll/contains queries with a secondary index:
// Create the index
r.table("users").indexCreate("userEquipment", function(user) {
return user("equipment").map(function(equipment) {
return [ user("id"), equipment ];
});
}, {multi: true}).run(conn, callback);
// Query equivalent to:
// r.table("users").getAll(1).filter(function (user) {
// return user("equipment").contains("tent");
// });
r.table("users").getAll([1, "tent"], {index: "userEquipment"}).distinct().run(conn, callback);
My questions is if there's a way to do the same but for querying with multiple tags. What would be the equivalent to make this query possible with a secondary index?
r.table("users").getAll(1).filter(function (user) {
return user("equipment").contains("tent", "tent2");
});
Probably we can do this
r.table("users").getAll([1, "tent"]).filter(function (user) {
return user("equipment").contains("tent2");
});
So build a multi index as you did, and try to getAll first, so that part is efficient with index, then filter to continue ensure that equipment contains array we want.
Related
Originally, I make a GraphQL call as follows:
query getItems($filter_ids: [Int!], $filter: item_records_bool_exp) {
items(order_by: { negative: asc, parent: asc }, where: { level: { _in: [2, 3] } }) {
i18n {
value
}
id
parent
negative
}
filters(where: { category: { _eq: "PLAN" } }) {
id
value
}
}
Now, when I insert a new item, I update the cache using update function in the mutation options, and I'm supposed to use readQuery/readFragment and writeQuery/writeFragment to interact with the Apollo Cache as described here.
My question is, my readQuery calls always fail if I do not provide the exact same variables that I had previous provided to the original GraphQL query. Is there a way around this? In other words, can I just read objects from the cache by their ID irrespective of the original query that was used to fetch these objects?
I have a document schema like this:
{
"name":"",
"type":"",
"posts":[
{
"url":"",
"content":"",
...
},
{
"url":"",
"content":"",
...
}
...
]
}...
I forgot to create id's for each post on insertion in database. So i'm trying to create a query for that:
r.db('test').table('crawlerNovels').filter(function (x){
return x.keys().contains('chapters')
}).map(function (x){
return x('chapters')
}).map(
function(x){
return x.merge({id:r.uuid()})
}
)
instead this query return all posts with an id but doesn't actually update in the database. I tried using a forEach instead of a map function at the end this doesn't work
After lots of tweaking and frustration i figured it out:
r.db('test').table('crawlerNovels').filter(function (x){
return x.keys().contains('chapters')
}).update(function(novel){
return {"chapters":novel('chapters').map(
function(chapter){
return chapter.merge({"id":r.uuid()})
})}
},{nonAtomic:true})
I am hitting the following problem: Suppose that I have the following structure:
{
"id": 1,
"data": {
"arr": [{"text":"item1"}]
}
}
And the following query:
r.db('test').table('test').get(1).update(function (item) {
return {
data: {
arr: item('data')('arr').map(function (row) {
return r.branch(
row('text').eq('item1'),
row.merge({updated:true}),
row
)
})
}
}
})
I am listening for changes in this specific array only, and when the item is updated both create and delete events are emitted. I really need to receive an update event, e.g. old_val is not null and new_val is not null.
Thanks in advance guys
After all, I decided to drop the embedded array and use table joins, this avoids all possible hacks.
You can use something like this
r.db('test').table('test')('data')('arr').changes()
.filter(function(doc) {
return doc('new_val').ne(null).and(doc('old_val').ne(null))
})
I'll only show update to array. If you need to get access to other document field, try this:
r.db('test').table('test').changes()
.filter(function(doc) {
return doc('new_val')('data')('arr').ne(null).and(doc('old_val')('data')('arr').ne(null))
})
How to write outputFields, getFatQuery, getConfigs for create new item and update items list
Please take a look gist or live
Questions are
getFatQuery() {
return Relay.QL`
???
`;
}
getConfigs() {
return [???];
}
outputFields: {
???
},
The outputFields in your schema make up the GraphQL type CreateActivityPayload that will be generated from your schema.js file. A mutation is like a regular query, but with side effects. In outputFields you get to decide what's queryable. Since your store is the only thing in your app that can change as a result of this mutation, we can start with that.
outputFields: {
store: {
type: storeType,
resolve: () => store,
},
}
The fat query operates on these output fields. Here you tell Relay what could possibly change as a result of this mutation. Adding an activity could change the following fields:
getFatQuery() {
return Relay.QL`
fragment on CreateActivityPayload #relay(pattern: true) {
store {
activities
}
}
`;
}
Finally, the config tells Relay what to do with the query when it gets it, or even if it needs to be made at all. Here, you're looking to update a field after creating a new activity. Use the FIELDS_CHANGE config to tell Relay to update your store.
getConfigs() {
return [{
type: 'FIELDS_CHANGE',
fieldsIDs: {
store: this.props.storeId,
},
}];
}
See more: https://facebook.github.io/relay/docs/guides-mutations.html
Lets say I have a "category" table, each category has associated data in the "data" table and it has associated data in other tables "associated" and I want to remove a category with all it's associated data.
What I'm currently doing is something like this:
getAllDataIdsFromCategory()
.then(removeAllAssociated)
.then(handleChanges)
.then(removeDatas)
.then(handleChanges)
.then(removeCategory)
.then(handleChanges);
Is there a way to chain these queries on the db-side?
my functions currently look like this:
var getAllDataIdsFromCategory = () => {
return r
.table('data')
.getAll(categoryId, { index: 'categoryId' })
.pluck('id').map(r.row('id')).run();
}
var removeAllAssociated = (_dataIds: string[]) => {
dataIds = _dataIds;
return r
.table('associated')
.getAll(dataIds, { index: 'dataId' })
.delete()
.run()
}
var removeDatas = () => {
return r
.table('data')
.getAll(dataIds)
.delete()
.run()
}
notice that I cannot use r.expr() or r.do() since I want to do queries based on the result of the previous query.
The problem with my approach is that it won't work for large amounts of "data" since I have to bring all of the ids to the client side, and doing paging for it in the client side in a loop seems like a workaround.
You can use forEach for this:
r.table('data').getAll(categoryID, {index: 'categoryId'})('id').forEach(function(id) {
return r.table('associated').getAll(id, {index: 'dataId'}).delete().merge(
r.table('data').get(id).delete())
});