I using firebase, nodejs and i have a question how to query field exist some document.
Example :
Collections : users => document : A with field {
....
is_correct: true
}
document : B with field {
.....
}
In my above example , i have two document in collection users. On document A i have field is_correct: true and on document B field is_correct not exist.
My collection users about 15.000 document and it have 50 document contain field is_correct: true
When i write code look like :
await firestore.collection('users').where('is_correct', '==', true).get();
it can get correct me 50 document. But i don't understand it can using index on field is_correct or not ? And it can query best performance ? I understand firebase can't get document if field undefined. It impart in case ? Please help ? Thanks you
For a simple query like
firestore.collection('users').where('is_correct', '==', true)
you don't need to configure any index, Firestore does it automatically.
As you mentioned, only documents where the given field exists can match the query.
And this is the case also for Not-equal (!=) and not-in queries: they exclude documents where the given field does not exist, as explained in the documentation.
Also, note that a field exists when it's set to any value, including an empty string (""), null, and NaN (not a number).
So, in conclusion, if you want to query for documents where is_correct is not true, you need to create this field in these documents with a value different than true.
Related
I have to update a single field in an existed Firestore document.
However, I don't know if there is some difference between using
admin.firestore().doc('doc_id').set({name:'Bill'},{ merge: true })
or
admin.firestore().doc('doc_id').update({name:'Bill'})
If the document is:
{
name: Bart,
age: 18
}
Should .update(...) just update the field and not remove the field "age" in this case?
There is no difference between those two options for existing documents.
The difference between them is only evident for documents that don't exist. set() with merge will create the document if it does't exist, and update() will fail if it doesn't exist.
Here My query
model.db.aggregate([{$lookup: {from: 'orders', localField: 'prod_id',
foreignField: '_id', as: 'Col'}},{$match:{$text:
{$search:'Sale'}}}).exec((err,data) => {console.log(data);}]);
but error showing "$match with $text is only allowed as the first pipeline !!"
I just want to lookup many collection then only I have to match'Search' in all the data what we joined(lookup) before.
mongoDb version: 4.0
Anybody have an idea ? need Help !
Thanks !!
These all are my Example collections:
collection 1 ->
organization ={'_id':ObjectId("5b110a7b84a0442030a1e9cf"),'Org_name':'dhoni institute','Estd':'1945'}
collection 2 -> players= {'_id':ObjectId("45110a7b84a3542030a1e9cf"),'_name':'Ms dhoni','Org_id' = ObjectId("5b110a7b84a0442030a1e9cf") }
I am searching the text string 'dhoni' in Db..then I want all the documents which contains word 'dhoni' from these collections.
How to do ?
db.players.aggregate([{$match:{$text:{$search:'dhoni'}}},
{
$lookup{from:'organization',localField:'_id',foreignField:'Org_id',as:'org'}
}
]).exec((err,data) => {}
this is my code It only matches the string from 'players' collection .I need matched 'players' collection documents as well as 'Organization' collection documents.
I cannot create new collection because after loopup data may be a huge data so
I cannot inserting new large data every time search
How to match the string after lookup ?
As explained in official mongodb documentation,
$text performs a text search on the content of the fields indexed with a text index.
But indexes are reachable only by the first stage of an aggregation query. That's the reason of your error message.
The only way i see for you to use $text/$search is to perform your aggregation (without match stage), adding an $out stage to output to a new collection, create a text index on that collection, and perform your find query with $text/$search criteria.
Hope it helps.
What is wrong with this query?
const db = firebase.firestore()
const query = db.doc(this.props.user.uid).collection('statements').orderBy('uploadedOn', 'desc').limit(50)
I get the following error:
Uncaught Error: Invalid document reference. Document references must have an even number of segments, but FrMd6Wqch8XJm32HihF14tl6Wui2 has 1
at new FirestoreError (index.cjs.js:346)
at Function.DocumentReference.forPath (index.cjs.js:15563)
at Firestore.doc (index.cjs.js:15368)
at UploadStatementPresentation.componentWillMount (UploadStatementPage.jsx:61)
at UploadStatementPresentation.componentWillMount (createPrototypeProxy.js:44)
at callComponentWillMount (react-dom.development.js:6872)
at mountClassInstance (react-dom.development.js:6968)
at updateClassComponent (react-dom.development.js:8337)
at beginWork (react-dom.development.js:8982)
at performUnitOfWork (react-dom.development.js:11814)
Since you haven't described what exactly you're trying to query, I'll just point out that all documents must be in a collection, without exception. So, if you say this:
db.doc(this.props.user.uid)
Firestore assumes that the string you're passing to doc() contains both the collection and document id separated by a slash. But this seems to be highly unlikely in your case. You need to determine which collection the uid is in, and use that first when you build the reference to the collection you want to query. Assuming that you do have a statements subcollection in the uid document, and that some other collection contains the uid document, you'll have to specify the full path like this:
db.collection('that-other-collection').doc(this.props.user.uid).collection('statements')
Of course, only you know the actual structure of your data.
If you want to get a collection of documents with querying, you don’t have to specify a document id. Below code should work in this case.
const query = db.collection('statements').orderBy('uploadedOn', 'desc').limit(50)
Or if you want to get the document, you can pass the document id to doc() method. In that case, the code should be.
const query = db.collection('statements').doc(this.props.user.uid)
For more details about querying firestorm data: https://firebase.google.com/docs/firestore/query-data/get-data?authuser=0
For others having this issue, make sure that no document reference has an empty string.
I had this issue when using a get method with uid input as below and forgot to check if uid is empty
private fun getFullRef(uid: String): CollectionReference {
return ref.document(uid).collection(FireContact.SUB_PATH)
}
I want to do a solr search to see if a dynamic field exists or not.
Example:
Doc 1 {
Id: 111
Name: good
Tag_100_is: lsdkl
}
Doc 1 {
Id: 2
Name: not good
}
I want a query to retrieve doc 1.
Thank you in advance.
To query for whether a field exists or not, use field:[* TO *]. So in this case, you should get the document you want by using the query Tag_100_is:[* TO *].
If you want to get the document without the field, you'll have to invert the query (we start with : which are "all documents", then remove the documents that have the field):
q=*:* -Tag_100_is:[* TO *]
I apologize beforehand if this is a repeat question but i could not find any and i am a beginner.
I am making a filter for documents of db.
lets say I want to query 8 fields of documents written in a object
filter={key1:{lowerlimit: 'value', upperlimit:'value'},
key2:{lowerlimit: 'value', upperlimit:'value'},
key3:{lowerlimit: '', upperlimit:'value'},
key4:{lowerlimit: 'value', upperlimit:''},
key5:[],
key6:['value','value'],
key7:['value','value','value'],
key8:['value']}
now how do i write the logic of query so that the fields whose value is not specified will not get query. if i query all the parameters as they are. no documents will be displayed because 'key5' is empty array and using $in on it will result in no documents.
You'd want to remove the key5 field from your query object when it's empty.
if (!filter.key5.length) {
delete filter.key5;
}