I have a nested document structure like:
[
{
"id": "parent1",
"children": [
{
"id": "child1",
"foo": "bar"
},
{
"id": "child2",
"foo": "bar"
},
{
"id": "child3",
"foo": "bar"
}
]
},
{
"id": "parent2",
"children": [
{
"id": "child4",
"foo": "bar"
},
{
"id": "child5",
"foo": "bar"
}
]
}
]
I am able to write the following query in SQL syntax:
SELECT child, parent.id
FROM parent
JOIN child in parent.children
This gets me the following result:
[
{
"child": {
"id": "child1",
"foo": "bar"
},
"id": "parent1"
},
...
]
I wrote a similar query in LINQ using SelectMany clause as follows, but it throws an error stating SelectMany can have only 2 arguments.
collection.SelectMany(
parent => parent.children,
(parent, child) => new { child, parent.id });
You need to "push" the second lambda inside the first lambda with a nested Select, like this:
collection.SelectMany(
parent => parent.children.Select(child => new {
Child = child
, ParentId = parent.id
})
);
Related
I am not sure how I should set cart.items to a new array, I have already made a copy of the original cache because I learned Apollo does not let you directly edit the cache, but I am still getting the following error
Error: Cannot assign to read only property 'items' of object '#'
Do I need to make a copy of the items array? And if so how do I go about changing the array on the current objects item field?
Here are my console.logs
You can ignore the typename fields as they are irrelevant to the problem
addItem
{
"__typename": "Cart",
"items": [
{
"__typename": "CartItem",
"name": "Item 3"
},
{
"__typename": "CartItem",
"name": "Item 4"
},
{
"__typename": "CartItem",
"name": "New Item!"
}
]
}
carts
{
"carts": [
{
"__typename": "Cart",
"id": "1",
"items": [
{
"__typename": "CartItem",
"id": "1",
"name": "Item 1"
},
{
"__typename": "CartItem",
"id": "2",
"name": "Item 2"
}
]
},
{
"__typename": "Cart",
"id": "2",
"items": [
{
"__typename": "CartItem",
"id": "3",
"name": "Item 3"
},
{
"__typename": "CartItem",
"id": "4",
"name": "Item 4"
}
]
}
]
}
So it seems you need to remake the items array as well since items is its own gql object type the easiest way to do this was to do it all at once with a map.
Please note the comment as that was an important detail I learned
// IMPORTANT NOTE when updating the cache of a query you must return the
// same fields as the original query even if you aren't using them in the code
const GET_CARTS = gql`
query {
carts{
id
items{
id
name
}}} `;
const MUTATION = gql`
mutation AddItem($input:MutationAddItemInput!) {
addItem(input: $input){
items{
id
name
}
}
}
`;
const { loading, error, data } = useQuery(GET_CARTS)
const [addItem] = useMutation(MUTATION, {
// refetchQueries: [{ query: GET_CARTS }]
update(cache, { data: { addItem } }) {
// addItem is the response of the query of add item function
console.log({ addItem });
// #ts-ignore
let { carts } = cache.readQuery({ query: GET_CARTS });
console.log({ carts })
// make a new array out of the carts array and add the new item to the array if the id of the cart is 2
let newCarts = carts.map((cart: Cart) => {
if (cart.id === "2") {
return { ...cart, items: [...addItem.items] }
} else {
return cart
}
})
console.log({ newCarts });
cache.writeQuery({
query: GET_CARTS,
data: { carts: newCarts }
// data: { carts: [{ id: "1", items: [{ id: "2", name: "an item" }] }] }
})
}
})
And lastly you will call the addItem function from the use mutation hook
I am writing a GraphQL resolver that retrieves all vertices by a particular edge using the following query (created returns label person):
software {
created {
name
}
}
Which would resolve to the following Gremlin Query for each software node found:
g.V().hasLabel('software').has('name', 'ripple').in('created')
This returns a result that includes all properties of the object:
{
"result": [
{
"#type": "d",
"#rid": "#24:0",
"#version": 6,
"#class": "person",
"in_knows": [
"#35:0"
],
"name": "josh",
"out_created": [
"#32:0",
"#33:0"
],
"age": 32,
"#fieldTypes": "in_knows=g,out_created=g"
}
],
"dbStats": {
...
}
}
I realize that this will fall foul on GraphQL's N+1 query so i'm trying to batch queries together using a Dataloader pattern. (i'm also hoping to do property selections, so i'm not asking the database to return too much info)
So i'm trying to craft a query like so:
g.V().union(
__.hasLabel('software').has('name', 'ripple').
project('parent', 'child').by('id').
by(__.in('created').fold()),
__.hasLabel('software').has('name', 'lop').
project('parent', 'child').by('id').
by(__.in('created').fold())
)
But this results in the following where the props are missing and it just includes the id of the vertices I want:
{
"result": [
{
"parent": "ripple",
"child": [
"#24:0"
]
},
{
"parent": "lop",
"child": [
"#22:0",
"#23:0",
"#24:0"
]
}
],
"dbStats": {
...
}
}
My Question is, how can I have the Gremlin query return all of the props for the found vertices and none of the other props? Should I even been doing batching this way?
For anyone else reading, the query I was trying to write wouldn't work because the TraversalSet created in the .by(_.in('created') can't be cast from a List to an ElementMap as the stream cardinality wouldn't be enforced. (You can only have one record per row, I think?)
My working query would be to duplicate the keys for each row and specify the props needed (the query below is ok for gremlin 3.3 as used in ODB, otherwise if you've got < gremlin 3.4 replace the last by step with be(elementMap('name', 'age')):
g.V().union(
__.hasLabel('software').has('name', 'ripple').
as('parent').
in('created').as('child').
select('parent', 'child').
by(values('name')).
by(properties('id', 'name', 'age').
group().by(__.key()).
by(__.value())),
__.hasLabel('software').has('name', 'lop').
as('parent').
in('created').as('child').
select('parent', 'child').
by(values('name')).
by(properties('id', 'name', 'age').
group().by(__.key()).
by(__.value()))
)
So that you get a result like this:
{"data": [
{
"parent": "ripple",
"child": {
"id": 5717,
"name": "josh",
"age": 32
}
},
{
"parent": "lop",
"child": {
"id": 5709,
"name": "peter",
"age": 35
}
},
{
"parent": "lop",
"child": {
"id": 5713,
"name": "marko",
"age": 29
}
},
{
"parent": "lop",
"child": {
"id": 5717,
"name": "josh",
"age": 32
}
}
]
}
Which would allow you to create a lookup where you concat all results for "lop" and "ripple" into arrays.
Only articles that contain the EmailMarketing tag are needed.
I'm probably doing the wrong search on the tag, since it's an array of values, not a single object, but I don't know how to do it right, I'm just learning graphql. Any help would be appreciated
query:
query {
enArticles {
title
previewText
tags(where: {name: "EmailMarketing"}){
name
}
}
}
result:
{
"data": {
"enArticles": [
{
"title": "title1",
"previewText": "previewText1",
"tags": [
{
"name": "EmailMarketing"
},
{
"name": "Personalization"
},
{
"name": "Advertising_campaign"
}
]
},
{
"title": "title2",
"previewText": "previewText2",
"tags": [
{
"name": "Marketing_strategy"
},
{
"name": "Marketing"
},
{
"name": "Marketing_campaign"
}
]
},
{
"title": "article 12",
"previewText": "article12",
"tags": []
}
]
}
}
I believe you first need to have coded an equality operator within your GraphQL schema. There's a good explanation of that here.
Once you add an equality operator - say, for example _eq - you can use it something like this:
query {
enArticles {
title
previewText
tags(where: {name: {_eq: "EmailMarketing"}}){
name
}
}
}
Specifically, you would need to create a filter and resolver.
The example here may help.
I am working on a project where I have to create one to many relationships which will get all the list of records referenced by id in another table and I have to display all the selected data in the multi-select field (selectArrayInput). Please help me out in this, if you help with an example that would be great.
Thanks in advance.
Example:
district
id name
1 A
2 B
3 C
block
id district_id name
1 1 ABC
2 1 XYZ
3 2 DEF
I am using https://github.com/Steams/ra-data-hasura-graphql hasura-graphql dataprovider for my application.
You're likely looking for "nested object queries" (see: https://hasura.io/docs/1.0/graphql/manual/queries/nested-object-queries.html#nested-object-queries)
An example...
query MyQuery {
district(where: {id: {_eq: 1}}) {
id
name
blocks {
id
name
}
}
}
result:
{
"data": {
"district": [
{
"id": 1,
"name": "A",
"blocks": [
{
"id": 1,
"name": "ABC"
},
{
"id": 2,
"name": "XYZ"
}
]
}
]
}
}
Or...
query MyQuery2 {
block(where: {district: {name: {_eq: "A"}}}) {
id
name
district {
id
name
}
}
}
result:
{
"data": {
"block": [
{
"id": 1,
"name": "ABC",
"district": {
"id": 1,
"name": "A"
}
},
{
"id": 2,
"name": "XYZ",
"district": {
"id": 1,
"name": "A"
}
}
]
}
}
Setting up the tables this way...
blocks:
districts:
Aside: I recommend using plural table names as they are more standard, "districts" and "blocks"
Given data model structure like this,
{
Id: 123,
"string_facet": [
{
"name": "make",
"value": "Audi"
},
{
"name": "carListType",
"value": "PERSON EU"
},
{
"name": "modelType",
"value": ""
},
{
"name": "engineBrand",
"value": "APT"
},
{
"name": "typeDescription",
"value": "8D2"
}
],
"number_facet": [
{
"name": "typeNumber",
"value": 4614
},
{
"name": "serialNumber",
"value": 2
},
{
"name": "engineSize",
"value": 18
},
{
"name": "horsePower",
"value": 125
},
{
"name": "kw",
"value": 92
},
{
"name": "engineVolume",
"value": 1781
},
{
"name": "listType",
"value": 0
}
],
"dateTime_facet": [
{
"name": "fromDate",
"value": "1999-04-01T00:00:00"
},
{
"name": "toDate",
"value": "2000-10-01T00:00:00"
}
]
}
I want to get aggregates facet names, and values per name. However, I'm only interested in facets that have specific names, such as: make and engineBrand. Note that facets are of type nested.
I have tried the following .NEST expression, but it still returns all of the facet names.
.Global("global", g => g
.Aggregations(ag => ag
.Filter("global_makes", f => f
.Filter(ff => ff
.Nested(n => n
.Path("string_facet")
.Filter(pf => pf.Term("string_facet.name", "make")))
)
.Aggregations(agg => agg
.Nested("nested_string_facet", nested => nested
.Path("string_facet")
.Aggregations(stringFacet => stringFacet
.Terms("name", nameAgg => nameAgg.Field("string_facet.name").Size(0)
.Aggregations(nameAggNext => nameAggNext
.Terms("value", valueAgg => valueAgg.Field("string_facet.value").Size(0))
)
)
)
)
)
)
)
)
);
I have a filter within global (to lose scope of a passed in query), and then filter only on string_facet.name which match "make", but results still include all other names as well. How do I filter out aggregation to include only buckets where name is "make"?
This helped. https://github.com/elastic/elasticsearch/issues/4449
Essentially had to move filter part deeper into aggregation.