I am trying to store network layout in Couch DB, but my solution provides rather randomized graph.
I store a nodes with a document:
{_id ,
nodeName,
group}
and storing links in traditional:
{_id, source_id, target_id, value}
Following multiple tutorials on handling joins and multiple relationship in Couch DB I created view:
function(doc) {
if(doc.type == 'connection') {
if (doc.source_id)
emit("source", {'_id': doc.source_id});
if(doc.target_id)
emit("target", {'_id': doc.target_id});
}
}
which should have emitted sequence of source and target id, then I pass it to the list function with include_docs=true, assumes that source and target come in pairs stitches everything back in a structure like this:
{
"nodes":[
{"nodeName":"Name 1","group":"1"},
{"nodeName":"Name 2","group":"1"},
],
"links": [
{"source":7,"target":0,"value":1},
{"source":7,"target":5,"value":1}
]
}
Although my list produce a proper JSON, view map returns number of rows of source docs and then target docs.
So far I don't have any ideas how to make this thing working properly - I am happy to fetch additional values from document _id in the list, but so far I havn't find any good examples.
Alternative ways of achieving the same goal are welcome. _id values are standard for CouchDB so far.
Update: while writing a question I came up with different view which sorted my immediate problem, but I still would like to see other options.
updated map:
function(doc) {
if(doc.type == 'connection') {
if (doc.source_id)
emit([doc._id,0,"source"], {'_id': doc.source_id});
if(doc.target_id)
emit([doc._id,1,"target"], {'_id': doc.target_id});
}
}
Your updated map function makes more sense. However, you don't need 0 and 1 in your key since you have already "source"and "target".
Related
I read and try a lots of things just to add a field witch is in relation.
One Dance have a level (beginner, improver...) and one Level have a Style (Country music, disco...). So for a dance I can get the level and associate style. Dance is MTO with Level, and Level is MTO with Style. It work fine in traditionnel controller and in Dance Index twig I can do
{{ dance.level.style }}
It's work fine.
Impossible for me to do that in EasyAdmin: In Danse Crud Controller
yield AssociationField::new('level');
is naturally working fine but how adding the style name? I'm not familiar with Queribuilder if it's the solution. I read Symfony Documentation easyadmin about unmapped fields but I don't undestand "createIndexQueryBuilder" parameters. If you can help me to progress. Thank's in advance
I don't find examples in stack with Easyadmin 4. And (I'm sorry), documentation is not very clear for me.
Example:
class UserCrudController extends AbstractCrudController
{
// ...
public function configureFields(string $pageName): iterable
{
return [
TextField::new('fullName'),
// ...
];
}
public function createIndexQueryBuilder(SearchDto $searchDto, EntityDto $entityDto, FieldCollection $fields, FilterCollection $filters): QueryBuilder
{
$queryBuilder = parent::createIndexQueryBuilder($searchDto, $entityDto, $fields, $filters);
// if user defined sort is not set
if (0 === count($searchDto->getSort())) {
$queryBuilder
->addSelect('CONCAT(entity.first_name, \' \', entity.last_name) AS HIDDEN full_name')
->addOrderBy('full_name', 'DESC');
}
return $queryBuilder;
}
}
Why we have "entity.first_name" (why entity word and not entityDto...). dump parameters don't give me persuasive results
Easy finally.
You can choice the field you want to be rendered. Basically add __toString in Entity.
In my case just add for a many to many relation:
AssociationField::new('dances')
->setFormTypeOption('choice_label','level.style'),
The documentation does not have any examples on how to add a subcollection to a document. I know how to add document to a collection and how to add data to a document, but how do I add a collection (subcollection) to a document?
Shouldn't there be some method like this:
dbRef.document("example").addCollection("subCollection")
Edit 13 Jan 2021:
According to the updated documentation regarding array membership, now it is possible to filter data based on array values using whereArrayContains() method. A simple example would be:
CollectionReference citiesRef = db.collection("cities");
citiesRef.whereArrayContains("regions", "west_coast");
This query returns every city document where the regions field is an array that contains west_coast. If the array has multiple instances of the value you query on, the document is included in the results only once.
Assuming we have a chat application that has a database structure that looks similar to this:
To write a subCollection in a document, please use the following code:
DocumentReference messageRef = db
.collection("rooms").document("roomA")
.collection("messages").document("message1");
Creating a messages collection and calling addDocument() 1000 times will be expensive for sure, but this is how Firestore works. You can switch to Firebase Realtime Database if you want where the number of writes doesn't matter. But regarding Supported Data Types in Firestore, in fact, you can use an array because it is supported. In Firebase Realtime database you could also use an array, but this is an anti-pattern. One of the many reasons Firebase recommends against using arrays is that it makes the security rules impossible to write.
Cloud Firestore can store arrays, but it does not support querying array members or updating single array elements. However, you can still model this kind of data by leveraging the other capabilities of the Cloud Firestore. Here is the documentation where it is very well explained.
You also cannot create a subcollection with 1000 messages, add all of them to the database, and expect it to be considered a single record. It will be considered one write operation for every message, in total 1000 operations. The picture above does not show how to retrieve data, it shows a database structure in which you have something like this:
collection -> document -> subCollection -> document
Here's a variation where the subcollection is storing ID values at the collection level, rather than within a document where the subcollection is a field there with additional data.
This is useful for connecting a 1-to-Many ID mapping w/out having to drill through an additional document:
function fireAddStudentToClassroom(studentUserId, classroomId) {
var db = firebase.firestore();
var studentsClassroomRef =
db.collection('student_class').doc(classroomId)
.collection('students');
studentsClassroomRef
.doc(studentUserId)
.set({})
.then(function () {
console.log('Document Added ');
})
.catch(function (error) {
console.error('Error adding document: ', error);
});
}
Thanks to #Alex's answer
This answer a bit off from the original question here, where it explicitly asks for adding a collection to a document. However, after searching for a solution for this scenario and not finding any mention in docs or on SO, this post seems like a reasonable place to share the findings
Here's my code:
firebase.firestore().collection($scope.longLanguage + 'Words').doc($scope.word).set(wordData)
.then(function() {
console.log("Collection added to Firestore!");
var promises = [];
promises.push(firebase.firestore().collection($scope.longLanguage + 'Words').doc($scope.word).collection('AudioSources').doc($scope.accentDialect).set(accentDialectObject));
promises.push(firebase.firestore().collection($scope.longLanguage + 'Words').doc($scope.word).collection('FunFacts').doc($scope.longLanguage).set(funFactObject));
promises.push(firebase.firestore().collection($scope.longLanguage + 'Words').doc($scope.word).collection('Translations').doc($scope.translationLongLanguage).set(translationObject));
Promise.all(promises).then(function() {
console.log("All subcollections were added!");
})
.catch(function(error){
console.log("Error adding subcollections to Firestore: " + error);
});
})
.catch(function(error){
console.log("Error adding document to Firestore: " + error);
});
This makes a collection EnglishWords, which has a document of. The document of has three subcollections: AudioSources (recordings of the word in American and British accents), FunFacts, and Translations. The subcollection Translations has one document: Spanish. The Spanish document has three key-value pairs, telling you that 'de' is the Spanish translation of 'of'.
The first line of the code creates the collection EnglishWords. We wait for the promise to resolve with .then, and then we create the three subcollections. Promise.all tells us when all three subcollections are set.
IMHO, I use arrays in Firestore when the entire array is uploaded and downloaded together, i.e., I don't need to access individual elements. For example, an array of the letters of the word 'of' would be ['o', 'f']. The user can ask, "How do I spell 'of'?" The user isn't going to ask, "What's the second letter in 'of'?"
I use collections when I need to access individual elements, a.k.a. documents. With the older Firebase Realtime Database, I had to download arrays and then iterate through the arrays with forEach to get the element I wanted. This was a lot of code, and with a deep data structure and/or large arrays I was downloading tons of data that I didn't need, and slowing my app running forEach loops on large arrays. Firestore puts the iterators in the database, on their end, so that I can request a single element and it sends me just that element, saving me bandwidth and making my app run faster. This might not matter for a web app, if your computer has a broadband connection, but for mobile apps with poor data connections and slow devices this is important.
Here are two pictures of my Firestore:
From the docs:
You do not need to "create" or "delete" collections. After you create the first document in a collection, the collection exists. If you delete all of the documents in a collection, it no longer exists.
Here i faced the same issue and solve with the answere of #Thomas David Kehoe
db.collection("First collection Name").doc("Id of the document").collection("Nested collection Name").add({
//your data
}).then((data) => {
console.log(data.id);
console.log("Document has added")
}).catch((err) => {
console.log(err)
})
too late for an answer but here is what worked for me,
mFirebaseDatabaseReference?.collection("conversations")?.add(Conversation("User1"))
?.addOnSuccessListener { documentReference ->
Log.d(TAG, "DocumentSnapshot written with ID: " + documentReference.id)
mFirebaseDatabaseReference?.collection("conversations")?.document(documentReference.id)?.collection("messages")?.add(Message(edtMessage?.text.toString()))
}?.addOnFailureListener { e ->
Log.w(TAG, "Error adding document", e)
}
add success listener for adding document and use firebase generated ID for a path.
Use this ID for the complete path for a new collection you want to add.
I.E. - dbReference.collection('yourCollectionName').document(firebaseGeneratedID).collection('yourCollectionName').add(yourDocumentPOJO/Object)
Okay so I recently faced a similar problem given the recent update in the firebase/firestore documentation.
And here is a solution that worked for me
const sendMessage = async () => {
await setDoc(doc(db, COLLECTION_NAME, projectId, SUB_COLLECTION_NAME, nanoid()), {
text:'this is a sample text',
createdAt: serverTimestamp(),
name: currentUser?.firstName + ' ' + currentUser?.lastName,
photoUrl: currentUser?.photoUrl,
userId: currentUser?.id,
});
}
You can find a similar example in the docs
https://firebase.google.com/docs/firestore/data-model#web-version-9_3
chat room
If you wish to listen for live update you can use a similar method as follows
const messagesRef = collection(db, COLLECTION_NAME, projectId, SUB_COLLECTION_NAME)
const liveUpdate = async () => {
const queryObj = query(messagesRef, orderBy("createdAt"), limit(25));
onSnapshot(queryObj, (querySnapshot) => {
const msgArr: any = [];
querySnapshot.forEach((doc) => {
msgArr.push({ id: doc.id, ...doc.data() })
});
console.log(msgArr);
});
}
There is no separate method to add sub-collection into the document.
You can just call the collection method itself.
If the collection exists it will reference that otherwise create a new one.
dbRef.document("example").collection("subCollection")
I have a question about the query based on the predefined constraints in PopotoJs. In this example, the graph can be filtered based on the constraints defined in the search boxes. The sample file in this example visualizations folder, constraint is only defined for "Person" node. It is specified in the sample html file like the following:
"Person": {
"returnAttributes": ["name", "born"],
"constraintAttribute": "name",
// Return a predefined constraint that can be edited in the page.
"getPredefinedConstraints": function (node) {
return personPredefinedConstraints;
},
....
In my graph I would like to apply that query function for more than one node. For example I have 2 nodes: Contact (has "name" attribute) and Delivery (has "address" attribute)
I succeeded it by defining two functions for each nodes. However, I also had to put two search box forms with different input id (like constraint1 and constraint2). And I had to make the queries in the associated search boxes.
Is there a way to make queries which are defined for multiple nodes in one search box? For example searching Contact-name and/or Delivery-adress in the same search box?
Thanks
First I’d like to specify that the predefined constraints feature is still experimental (but fully functional) and doesn’t have any documentation yet.
It is intended to be used in configuration to filter data displayed in nodes and in the example the use of search boxes is just to show dynamically how it works.
A common use of this feature would be to add the list of predefined constraint you want in the configuration for every node types.
Let's take an example:
With the following configuration example the graph will be filtered to show only Person nodes having "born" attribute and only Movie nodes with title in the provided list:
"Person": {
"getPredefinedConstraints": function (node) {
return ["has($identifier.born)"];
},
...
}
"Movie": {
"getPredefinedConstraints": function (node) {
return ["$identifier.title IN [\"The Matrix\", \"The Matrix Reloaded\", \"The Matrix Revolutions\"]"];
},
...
}
The $identifier variable is then replaced during query generation with the corresponding node identifier. In this case the generated query would look like this:
MATCH (person:`Person`) WHERE has(person.born) RETURN person
In your case if I understood your question correctly you are trying to use this feature to implement a search box to filter the data. I'm still working on that feature but it won't be available soon :(
This is a workaround but maybe it could work in your use case, you could keep the search box value in a variable:
var value = d3.select("#constraint")[0][0].value;
inputValue = value;
Then use it in the predefined constraint of all the nodes type you want.
In this example Person will be filtered based on the name attribute and Movie on title:
"Person": {
"getPredefinedConstraints": function (node) {
if (inputValue) {
return ["$identifier.name =~ '(?i).*" + inputValue + ".*'"];
} else {
return [];
}
},
...
}
"Movie": {
"getPredefinedConstraints": function (node) {
if (inputValue) {
return ["$identifier.title =~ '(?i).*" + inputValue + ".*'"];
} else {
return [];
}
},
...
}
Everything is in the HTML page of this example so you can view the full source directly on the page.
#Popoto, thanks for the descriptive reply. I tried your suggestion and it worked pretty much well. With the actual codes, when I make a query it was showing only the queried node and make the other node amount zero. I wanted to make a query which queries only the related node while the number of other nodes are still same.
I tried a temporary solution for my problem. What I did is:
Export the all the node data to JSON file, search my query constraint in the exported JSONs, if the file is existing in JSON, then run the query in the related node; and if not, do nothing.
With that way, of course I needed to define many functions with different variable names (as much as the node amount). Anyhow, it is not a propoer way, bu it worked for now.
Is like or rlike supported for searching a string in a collection's property value?
Does the collection need to define text type index for this to work? Unfortunately I can not create a text index for the property. There are 100 million documents and text index killed the performance (MongoDB is on single node). If this is not do-able without text index, its fine with me. I will look for alternatives.
Given below collection:
Message {
'payload' : 'XML or JSON string'
//few other properties
}
In grails, I created a Criteria to return me a list of documents which contain a specific string in the payload
Message.list {
projections {
like('payload' : searchString)
}
}
I tried using rlike('payload' : ".*${searchString}.*") as well. It did not result in any doc to me.
Note: I was able to get the document when I fired the native query on Mongo shell.
db.Message.find({payload : { $regex : ".*My search string.*" }}).pretty()
I got it working in a round about way. I believe there is a much better grails solution. Criteria approach did not work. So used the low level API converted the DBObjects to Domain objects.
def query = ['payload' : [ '$regex' : /${searchString}/ ] ]
def dbObjects = Message.collection.find(query).skip(offset).limit(defaultPageSize).toArray()
dbObjects?.collect { new Message(new JsonSlurper().parseText(it.toString()))}
Is there any mechanism for controlling the order of properties?
I cannot reproduce this in http://www.neo4j.org/console
Using Neo4j 1.9.2 Community if I do the following:
CREATE (m1 {`$type`: {moduleTypeName}, Name: 'M1', ModelNumber: 'MN1'})
Then later I get this node back from a cypher query using the REST cypher endpoint I get back...
{
"extensions": {},
"paged_traverse": "http://localhost:7575/db/data/node/3777/paged/traverse/{returnType}{?pageSize,leaseTime}",
"outgoing_relationships": "http://localhost:7575/db/data/node/3777/relationships/out",
"traverse": "http://localhost:7575/db/data/node/3777/traverse/{returnType}",
"all_typed_relationships": "http://localhost:7575/db/data/node/3777/relationships/all/{-list|&|types}",
"property": "http://localhost:7575/db/data/node/3777/properties/{key}",
"all_relationships": "http://localhost:7575/db/data/node/3777/relationships/all",
"self": "http://localhost:7575/db/data/node/3777",
"properties": "http://localhost:7575/db/data/node/3777/properties",
"outgoing_typed_relationships": "http://localhost:7575/db/data/node/3777/relationships/out/{-list|&|types}",
"incoming_relationships": "http://localhost:7575/db/data/node/3777/relationships/in",
"incoming_typed_relationships": "http://localhost:7575/db/data/node/3777/relationships/in/{-list|&|types}",
"create_relationship": "http://localhost:7575/db/data/node/3777/relationships",
"data": {
"ModelNumber": "MN1",
"$type": "ModuleType",
"Name": "M1"
}
}
I'm using http://james.newtonking.com/pages/json-net.aspx to parse JSON and for it to automatically infer an object type, the $type property must be first. It makes sense when parsing the JSON in a stream when you don't want to load the entire thing into memory first.
It does not appear to be alphabetical, and it does not seem to be random either. It seems that the order is consistent for different object types, but inconsistent between them.
I have pulled the node in the Shell as well and so it seems that the order does not depend on how I get the node, but is not related to the order in which I create the node either.
Properties have no guaranteed order. Do not take any assumptions on a 'maybe' ordering. An upcoming version might change this assumed behaviour and break your code.
I guess it is simpler in Cypher to not return the node itself in favour of a list of properties, e.g.
START node=node(<myid>)
RETURN node.`$type`, node.ModelNumber, node.Name
This has defined columns.
Definitively it seems not to have that functionality.
My workaround for it it is to alias the properties with a prefix in the format aXX_, as in a01_, a02, a03_ and then remove it in the code.
Not pretty, not great, but it works as neo4j respects numerical order.
It needs a letter character at the beggining though, hence the "a" before the numbers.