Is it possible to query multiple keys in a single query? [duplicate] - firebase-realtime-database

This question already has an answer here:
Speed up fetching posts for my social network app by using query instead of observing a single event repeatedly
(1 answer)
Closed 1 year ago.
I am new to Firebase. The following is my database's structure.
{
"dvdStores": {
"store1": {
"movies": {
"0": "Don't Look Up",
"1": "Top Gun"
}
},
"store2": {
"movies": {
"0": "Jungle Book",
"1": "Taken"
}
},
"store3": {
"movies": {
"0": "The Matrix",
"1": "Home Alone"
}
},
"store4": {
"movies": {
"0": "The Lion King"
}
}
}
}
Can I get all the movies corresponding to multiple keys in a single query?
I would e.g. want to get all the movies corresponding to keys store1 and store4. Can this be done in a single query?
Thanks in advance :)

This is not possible. You must request them each individually. All queries for a node always get the entire node, including all of its nested children. Children cannot be selectively included or excluded.
It's worth noting also that there is not much overhead in making multiple requests. The data for each query is pipelined over a single socket connection, so as long as you keep that connected saturated with requests, you are not losing very much perceived performance.

Related

Complex queries in CouchDB across multiple types of documents

I'm relatively new to CouchDB (more specifically Cloudant if it matters) and I'm having a hard time wrapping my head around something.
Assume the following (simplified) document examples:
{ "docType": "school", "_id": "school1", "state": "CA" }
{ "docType": "teacher", "_id": "teacher1", "age": "40", "school": "school1" }
I want to find all the teachers aged $age (eg. 40) in state $state (eg. CA).
Views only consider one document at a time; that is queries can't directly combine data from different documents. You can query across multiple fields in the same document using Cloudant Query. You can write a selector directly in the Cloudant dashboard. Something like
"selector": {
"age": {
"$gte": 40
},
"state": {
"$eq": "CA"
}
}
See https://cloud.ibm.com/docs/services/Cloudant/tutorials?topic=cloudant-creating-an-ibm-cloudant-query
with the full reference here: https://cloud.ibm.com/docs/services/Cloudant/tutorials?topic=cloudant-query
You could also use a so-called linked document to emulate basic joins, as outlined in the CouchDB docs https://docs.couchdb.org/en/stable/ddocs/views/joins.html

Join two nodes in Firebase

I'm working on an app, which is supposed to show data from two nodes(Firebase). Firebase DB is structured as:
{
"College": {
"4F2EAB65": {
"id": "4F2EAB65",
"name": "SomeCollege"
},
"A3C2ED31": {
"id": "A3C2ED31",
"name": "OtherCollege"
},
"F967B5A0": {
"id": "F967B5A0",
"name": "CoolCollege"
}
},
"Student": {
"3E20545B": {
"college-ID": "4F2EAB65",
"id": "3E20545B",
"name": "A"
},
"6FDEE194": {
"college-ID": "F967B5A0",
"id": "6FDEE194",
"name": "B"
}
}
I want to fetch student details having details: "id", "name", "college-ID", "college-Name"(Need to fetch "college-Name" by "college-ID").
I've achieved this using for loop at front end. Is there any way to get this achieved at Firebase server, also can we make something like join (SQL).
Thanks.
There is no support for server-side joins in the Firebase Realtime Database. Client-side joins are quite normal.
The alternative is to duplicate the data upon writing, so that you don't have to read from two locations.
What's best for your application is a matter of personal preference, your comfort level with the code involved vs data duplication, and the use-cases of your app.
Client-side jons are likely not as slow as you may think. See http://stackoverflow.com/questions/35931526/speed-up-fetching-posts-for-my-social-network-app-by-using-query-instead-of-obse/35932786#35932786

Retrieving labels from multiple JIRA Subtasks via JIRA API

I am creating a reporting dashboard with the intent of getting multiple tickets/issues for a project. As most of you probably know, a JIRA issue can have subtasks. These subtasks can have labels.
I want to retrive all labels for every subtask.
I already have the project API request implemented which returns the parent ticket ids along with the issue/ticket number of all subtasks. The problem is the data returned from this request does not include the labels for the subtasks themselves.
I can loop over each subtask number and make an additional API request for each one to get the labels, however this would result in a large number of requests.
Looking through JIRA's API I cannot find a better way of doing this. Google seems to return a lot of results about plugins and version differences with Cloud vs. Server but I have not found a better solution.
Their API makes reference to an expand option but I have yet to figure out a way to make that work for subtask labels (I might be missing something obvious).
If anyone has experience with a similar situation I would appreciate hearing any advice you could offer. Thanks!
What I have currently:
Project API Request:
https://ourcompanyhere.atlassian.net/rest/api/2/search
with an additional parameter added for the JQL string of:
project=PROJECTNAME AND fixversion=version
This returns all the tickets in the project with subtasks but not the subtask labels.
I can loop over the returned data from the above request and make an additional request for each:
https://ourcompanyhere.atlassian.net/rest/api/2/issue/ticketNumberHere
JSON Response
Here is the partial JSON response back (full response is huge and I've removed key information) however this is the complete information for a ticket, with a subtask which has labels. As you can see the labels section of the subtask is completely missing.
ErrorDetail=,
Mimetype=application/json,
Statuscode=200 OK,
Filecontent= {
"expand":"schema,names",
"startAt":0,
"maxResults":50,
"total":3,
"issues":[
{
"expand":"operations,versionedRepresentations,editmeta,changelog,renderedFields",
"id":"24209",
"self":"https://[instance].atlassian.net/rest/api/latest/issue/24209",
"key":"DEV-3089",
"fields":{
"issuetype":{
"self":"https://[instance].atlassian.net/rest/api/2/issuetype/10005",
"id":"10005",
"description":"A new feature of the product, which has yet to be developed.",
"iconUrl":"https://[instance].atlassian.net/secure/viewavatar?size=xsmall&avatarId=10311&avatarType=issuetype",
"name":"New Feature",
"subtask":false,
"avatarId":10311
},
"project":{
"self":"https://[instance].atlassian.net/rest/api/2/project/10000",
"id":"10000",
"key":"DEV",
"name":"Development Queue",
"avatarUrls":{
}
},
"customfield_11000":null,
"fixVersions":[
{
"self":"https://[instance].atlassian.net/rest/api/2/version/14600",
"id":"14600",
"description":"",
"name":"",
"archived":false,
"released":true,
"releaseDate":"2017-09-15"
}
],
"resolution":{
"self":"https://[instance].atlassian.net/rest/api/2/resolution/10000",
"id":"10000",
"description":"Work has been completed on this issue.",
"name":"Done"
},
"customfield_10500":"",
"customfield_10700":null,
"customfield_10900":null,
"resolutiondate":"2017-09-15T09:19:37.000-0400",
"workratio":-1,
"watches":{
"self":"https://[instance].atlassian.net/rest/api/2/issue/DEV-3089/watchers",
"watchCount":2,
"isWatching":true
},
"lastViewed":null,
"created":"2017-05-02T10:15:08.000-0400",
"customfield_10022":null,
"customfield_10100":null,
"priority":{
"self":"https://[instance].atlassian.net/rest/api/2/priority/3",
"iconUrl":"https://[instance].atlassian.net/images/icons/priorities/medium.svg",
"name":"Medium",
"id":"3"
},
"customfield_10300":null,
"labels":[
"[label1]",
"[label2]",
"[label3]",
"[label4]",
"[label5]",
"[label6]"
],
"customfield_10016":null,
"customfield_10017":null,
"versions":[
],
"issuelinks":[
],
"assignee":{
"self":"https://[instance].atlassian.net/rest/api/2/user?username=",
"name":"[name]",
"key":"[name]",
"accountId":"[account]",
"emailAddress":"[email]",
"avatarUrls":{
},
"displayName":"[name]",
"active":true,
"timeZone":"America/New_York"
},
"updated":"2017-09-15T09:19:36.000-0400",
"status":{
"self":"https://[instance].atlassian.net/rest/api/2/status/6",
"description":"The issue is considered finished, the resolution is correct. Issues which are closed can be reopened.",
"iconUrl":"https://[instance].atlassian.net/images/icons/statuses/closed.png",
"name":"Closed",
"id":"6",
"statusCategory":{
"self":"https://[instance].atlassian.net/rest/api/2/statuscategory/3",
"id":3,
"key":"done",
"colorName":"green",
"name":"Done"
}
},
"components":[
],
"description":"[description]",
"customfield_10010":null,
"customfield_10011":null,
"customfield_11100":null,
"customfield_10012":null,
"customfield_10013":null,
"customfield_10015":"",
"customfield_10005":null,
"customfield_10006":null,
"customfield_10600":null,
"customfield_10007":null,
"customfield_10008":null,
"customfield_10800":null,
"customfield_10009":null,
"summary":"[summary]",
"creator":{
"self":"https://[instance].atlassian.net/rest/api/2/user?username=",
"name":"",
"key":"",
"accountId":"",
"emailAddress":"",
"avatarUrls":{
},
"displayName":"",
"active":true,
"timeZone":"America/New_York"
},
"subtasks":[
{
"id":"30213",
"key":"DEV-4118",
"self":"https://[instance].atlassian.net/rest/api/2/issue/30213",
"fields":{
"summary":"",
"status":{
"self":"https://[instance].atlassian.net/rest/api/2/status/6",
"description":"The issue is considered finished, the resolution is correct. Issues which are closed can be reopened.",
"iconUrl":"https://[instance].atlassian.net/images/icons/statuses/closed.png",
"name":"Closed",
"id":"6",
"statusCategory":{
"self":"https://[instance].atlassian.net/rest/api/2/statuscategory/3",
"id":3,
"key":"done",
"colorName":"green",
"name":"Done"
}
},
"priority":{
"self":"https://[instance].atlassian.net/rest/api/2/priority/3",
"iconUrl":"https://[instance].atlassian.net/images/icons/priorities/medium.svg",
"name":"Medium",
"id":"3"
},
"issuetype":{
"self":"https://[instance].atlassian.net/rest/api/2/issuetype/10009",
"id":"10009",
"description":"",
"iconUrl":"https://[instance].atlassian.net/secure/viewavatar?size=xsmall&avatarId=10303&avatarType=issuetype",
"name":"Testing Issue",
"subtask":true,
"avatarId":10303
}
}
}
"reporter":{
"self":"https://[instance].atlassian.net/rest/api/2/user?username=",
"name":"",
"key":"",
"accountId":"",
"emailAddress":"",
"avatarUrls":{
},
"displayName":"",
"active":true,
"timeZone":"America/New_York"
},
"customfield_10000":"2017-09-01T12:35:54.706-0400",
"customfield_10001":null,
"customfield_10200":null,
"customfield_10400":null,
"customfield_10004":null,
"environment":null,
"duedate":null,
"votes":{
"self":"https://[instance].atlassian.net/rest/api/2/issue/DEV-3089/votes",
"votes":0,
"hasVoted":false
}
}
}
]
}
Inspect the response for the /search endpoint again. On a completely empty JIRA Cloud instance I created a Project, one Issue and added a Sub-task for it. Calling the /search endpoint returns a list with two Issues (so, the Issue itself and its Sub-task) and for both there's a field called labels with an array of all the Labels attached to it.
The following is an abbreviated response with all unrelated data removed.
{
"startAt": 0,
"maxResults": 50,
"total": 2,
"issues": [
{
"key": "TEST-1",
"fields": {
"labels": []
}
},
{
"key": "TEST-2",
"fields": {
"parent": {
"key": "TEST-1"
},
"labels": [
"VOILA"
]
}
}
]
}
EDIT
After looking at the response then yes, the array in subtasks is really simple and cannot be separately expanded. You need to do the search, then parse out all the subtasks that you're interested in and either do
a separate /issue/[key] request for each one
a /search for those specific keys
After doing some further research I found a better way to do this. I'm still not getting the subtask labels back but instead of looping over each subtask and sending a separate request for each, you can do one API call using JQL like this:
https://[instance].atlassian.net/rest/api/latest/search?jql=project=[project] AND KEY IN ([comma separated list of tickets])&fields=labels'
The
&fields=labels
part drastically reduces the amount of information returned. So now I can just do a total of two calls and get everything I need. :)
Wanted to post this in case anyone runs into a similar situation.

Observe changes in nested children on Firebase

I'm using iOS/Swift with Firebase.
My question is simle, how do I observe nested children (without specifying the parent).
To be more specific, I'm building a messages app and when the user sends a message with state Sending, I want the server (for now it's a separate server from Firebase, since I didn't know how to do it without one) to update it to Sent.
In order to do that, I plan on observing my /messages path for any children added, so I can change the state to Sent.
The problem is, my messages are nested, just like with Firebase's example:
"messages": {
"one": {
"m1": {
"state": "Sending",
"message": "Some message",
},
"m2": { ... },
"m3": { ... }
},
"two": { ... },
"three": { ... }
}
Because the rooms (one, two, three) are not always the same, I don't want to observe each one of them, I want to observer something like /messages/*/ for children added.
So any time a message is added (doesn't matter to which room) I want to change it's state from Sending to Sent.

Core data how to handle relationships based on IDs

I have a rest webservice that gets me the a json response in the following structure :
{
"Categories": [
{
"category_id":1,
"category_name":"category 1"
},
{
"category_id":2,
"category_name":"category 2"
}
],
"Products":[
{
"product_id":1,
"product_name":"Product 1",
"category_id":1
},
{
"product_id":2,
"product_name":"Product 2",
"category_id":1
},
{
"product_id":3,
"product_name":"Product 3",
"category_id":2
}
]
}
I am creating a Core data model for my iOS application in which i can save this data as you can see below .
The problem is how can I use the relationships that I have created in my core data model to map this data?
The silliest idea that comes to my mind is to search for each product's category based on the category id and then set it like
Product.category = category [i] , but there got to be a easier way to do this.
Based on your use of ObjectMapper you will need to make the connections yourself using your 'silly idea (TM)'. You should look at doing the fetch as a batch and sorting the results to minimise calls to Core Data and to make the mapping simple.
If you chose to use RestKit then you could just configure the mappings for the objects and the identities used to link them and RestKit will do the lifting work. It could be a bit of work for you...

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