How to filter list of id on firebase cloud firestore? - firebase

Question

I have two collections. (applyJobs and Jobs and users). When users apply for a job, I store that record inside applyJobs collection. Like this:
applyId:****,
jobId:*****,
userId:*****
Now, I want to show all apply for jobs by a user.
First: Get logged user id, I store locally logged user id. So, I can get loggged user id.
Second: I filter Apply Jobs by that id. like this, var ref = _db.collection('applyJobs').where('userId',isEqualTo: uid);. I here I didn't call users collection to get uid. because I already store uid on locally. Is it best practice?
Third: I store result here List<ApplyJobsModelClass>. I want to get all jobs by a list of id. How do I filter it?
This is way I tried it. But this is not list of IDs. only one id.
streamApplyJob(List<String> jobId) {
Collection('jobs').document(jobId);
}
And I tried this way too.
Stream<List<JobModel>> streamApplyJob(List<String> jobId) {
var ref = _db.collection('jobs').where('jobId',isEqualTo: jobId);
return ref.snapshots().map((list) =>
list.documents.map((doc) => JobModel.fromFirestore(doc)).toList());
}
tried to get length, but result is 0
db.streamApplyJob(jobIds).listen((v)=>{
print(v.length)
});
Full Code
Database side
///Get a stream of apply jobs
Stream<List<ApplyJobModel>> streamApplyJobs(String uid) {
var ref = _db.collection('applyJobs').where('userId',isEqualTo: uid);
return ref.snapshots().map((list) =>
list.documents.map((doc) => ApplyJobModel.fromFirestore(doc)).toList());
}
///Get a stream of a single document
Stream<List<JobModel>> streamApplyJob(List<String> jobId) {
var ref = _db.collection('jobs').where('jobId',isEqualTo: jobId);
return ref.snapshots().map((list) =>
list.documents.map((doc) => JobModel.fromFirestore(doc)).toList());
}
calling
List<String> jobIds = [];
void getData() {
db.streamApplyJobs(widget.uid).listen((listApplies) => {
for (int i = 0; i < listApplies.length; i++)
{jobIds.add(listApplies[i].jobId)},
});
db.streamApplyJob(jobIds).listen((v)=>{
print(v.length)
});
}
Solution(It's working now)- Is it best practice or are there other best way to do this?
Future<List<JobModel>> getJobs() async {
await db.streamJobs(true).listen((jobs) {
setState(() {
jobModel = jobs;
});
});
return jobModel;
}
Future getData() async {
await getJobs();
db.streamApplyJobs(widget.uid).listen((apply) => {
for (int j = 0; j < jobModel.length; j++)
{
for (int i = 0; i < apply.length; i++)
{
if (apply[i].jobId == jobModel[j].jobId)
{
jobModelNew.add(jobModel[j]),
}
}
}
});
}

Answer 1

I want to get all jobs by a list of id. How do I filter it?
There currently is no way to pass in a list of IDs to a Firestore query and get documents matching all those IDs. See Google Firestore - how to get document by multiple ids in one round trip? (which talks about doing this with document IDs), and Firebase Firestore - OR query (which talks about filtering for multiple values on a single field).
Unless your use-case happens to match the workaround mentioned in that second answer, you'll have to perform a separate query for each value, and merge the results in your application code.

Answer 2

Not sure if it is documented anywhere officially, but this is possible now!
.where(admin.firestore.FieldPath.documentId(), "in", [array, of, ids])
Found here: https://stackoverflow.com/a/52252264/10562805

Answer 3

Please take a look at this example. It binds a CollectionReference to a List.
Let me know if this is helpful.