I'm trying to access data that I have stored in datastore (in datastore mode). For some reason, I can't access any data it seems.
Things I've tried.
Access using a key
const datastore = new Datastore({projectId: '...'});
const key = datastore.key([<kind>, <id>]);
return datastore.get(key, (err, entity, x) => {
console.log("yolo", err, entity, x);
return entity;
});
Using a query
const query =
datastore.createQuery(<kind>);
return datastore.runQuery(query, (err, e, nq) => {
console.log(err, e, nq);
return e;
});
Both of the above yields no result. I am 100% sure I have typed the kind correctly.
So this was a stupid mistake on my end, but I keep the question in case someone else does the same mistake.
What I did when I created the entry in datastore was that I put it in a namespace, but then I didn't provide the namespace when I queried for it. Just providing the namespace and I was all good.
Related
I'm extremely new to using Firebase cloud functions, and I am struggling to find the error in my code. It is supposed to trigger on a firestore write and then copy that document into all of the user's feeds who follow that user who posted.
My current code is below:
exports.fanOutPosts = functions.firestore
.document('posts/{postId}')
.onCreate((snap, context) => {
var db = admin.firestore();
const post = snap.data();
const userID = post['author'];
const postCollectionRef = db.collection('friends').document(userID).collection('followers');
return postCollectionRef.get()
.then(querySnapshot => {
if (querySnapshot.empty) {
return null;
} else {
const promises = []
querySnapshot.forEach(doc => {
promises.push(db.collection('feeds').document(doc.key).collection('posts').document(post.key).update(data));
});
return Promise.all(promises);
}
});
});
So this successfully deploys to Firebase, but it receives this error when a document is created:
TypeError: db.collection(...).document is not a function
at exports.fanOutPosts.functions.firestore.document.onCreate (/workspace/index.js:22:60)
Line 22 is const postCollectionRef = db.collection('friends').document(userID).collection('followers');
I am unsure why this line is causing errors with the .get, but if anyone could point me in the right direction it would be much appreciated!
Given that this is the nodejs API, you'll want to use doc() instead of document(). Other languages might use document().
I found this info via the Admin SDK on CollectionReference https://googleapis.dev/nodejs/firestore/latest/CollectionReference.html
According to the reference, the collection should be defined as the following:
const postCollectionRef = db.collection(`friends/${userId}/followers`);
Using template literals will allow you to dynamically add variables into the collection ref.
I would also take a look into the else logic to use template literals within your return statement.
i tried to connect documentdb from my asp.net website but i am getting this error.
Entity with the specified id does not exist in the system
DocumentClientException: Entity with the specified id does not exist in the system
code as follows in aspx code behind
protected async void Page_Load(object sender, EventArgs e)
{
Response.Write("Page Load<br/>");
await GetData();
}
public async Task GetData()
{
try
{
Response.Write("<br/> Get Data function Start<br/><br/>");
using (var client = new DocumentClient(new Uri(ConfigurationManager.AppSettings["endpoint"]), ConfigurationManager.AppSettings["authKey"]))
{
//await client.OpenAsync();
RequestOptions reqOpt = new RequestOptions { PartitionKey = new PartitionKey(209) };
var parameters = new dynamic[] { 1 };
StoredProcedureResponse<object> result = await client.ExecuteStoredProcedureAsync<object>(
UriFactory.CreateStoredProcedureUri(ConfigurationManager.AppSettings["database"], ConfigurationManager.AppSettings["pcsd"], "GetMemberbyId"), reqOpt, parameters);
Response.Write(result.Response.ToString());
}
Response.Write("<br/><br/> Get Data function End");
}
catch (Exception ex)
{
Response.Write(ex.Message);
}
}
stored procedure as follows
function GetMemberbyId(memId) {
var collection = getContext().getCollection();
//return getContext().getResponse().setBody('no docs found');
// Query documents and take 1st item.
var isAccepted = collection.queryDocuments(
collection.getSelfLink(),
'SELECT * FROM root m where m.memberId='+memId,
function (err, feed, options) {
if (err) throw err;
// Check the feed and if empty, set the body to 'no docs found',
// else take 1st element from feed
if (!feed || !feed.length) getContext().getResponse().setBody('no docs found');
else getContext().getResponse().setBody(feed);
});
if (!isAccepted) throw new Error('The query was not accepted by the server.');
}
in my localhost it's working fine but website published to azure web apps and running i am getting above error
I just spent a couple of hours troubleshooting this, only to find that I had firewalled my instance to a point where I could not connect locally. Keep in mind that the Azure portal document query will obviously still work even when you have no direct access via the API / C# client.
Try setting the firewall to allow All Networks temporarily to check access.
I would check in the portal that the "GetMemberbyId" is the name of the stored procedure for the collection you are trying to run it on. Could be the stored procedure is on a different collection or that the stored procedure is named something else.
If that all checks out.. I have had more luck with the __.filter() way of querying documents on the server. See:
http://azure.github.io/azure-documentdb-js-server/
When issuing an "insert" statement to postgres, how can I get the ID of the row last inserted in the DB?
I tried "pg", "pg-native", "pg-connection", and a bunch of other packages. For each package, I tried the sync and async method. I read the thing that pretends to be package documentation. I checked the source code for the packages. For the life of me I can't figure this out, and I can't believe that I'm the only person to face this issue.
Any insight would be greatly appreciated.
The key here is using RETURNING id in your INSERT query.
The pg wiki has an example that shows how this is done.
// Let's pretend we have a user table with the 'id' as the auto-incrementing primary key
var queryText = 'INSERT INTO users(password_hash, email) VALUES($1, $2) RETURNING id'
client.query(queryText, ['841l14yah', 'test#te.st'], function(err, result) {
if (err) //handle error
else {
var newlyCreatedUserId = result.rows[0].id;
}
});
or with async/await:
const result = await client.query(queryText, ['841l14yah', 'test#te.st']);
const newlyCreatedUserId = result.rows[0].id;
I want to utilize Redis for saving and reading a dynamic list of users.
Essentially, Redis is Key-Value pair storage. How can I read all the saved users at once? (for example, creating a namespace "users/user_id")
And since I am a Redis beginner,
Do you think the use of Redis in the above case is proper/efficient?
Thanks.
When using key/values for storing objects you should create a domain specific key by combining the domain name plus the unique id. For example, a user object that might look like this:
// typical user data model
var User = function(params) {
if (!params) params = {};
this.id = params.id;
this.username = params.username;
this.email = params.email;
// other stuff...
};
Then domain key could be created like this:
var createUserDomainKey = function(id) {
return 'User:' + id;
};
If the id was 'e9f6671440e111e49f14-77817cb77f36' the key would be this:
User:e9f6671440e111e49f14-77817cb77f36
Since redis will store string values, you need to serialize, probably with json so to save the user object. Assuming a valid use object would would do something like this:
var client = redis.createClient(),
key = createUserDomainKey( user.id ),
json = JSON.stringify( user ) ;
client.set( key, json, function(err, result) {
if (err) throw err; // do something here...
// result is 'OK'
});
For simple fire-hose queries returning all users, you can do this:
var client = redis.createClient();
client.keys( createUserDomainKey( '*' ), function(err, keys) {
if (err) throw err; // do something here
// keys contains all the keys matching 'User:*'
});
Note that the redis folks discourage the use of 'keys' for production, so a better approach is to build your own index using sorted-set, but if your user list is limited to a few hundred, there is no problem.
And since it returns a list of keys, you need to loop through and get each user then parse the json string to recover the real object. Assuming a populated list of keys, you could do something like this:
var client = redis.getClient(),
users = [];
var loopCallback = function(err, value) {
if (!err && value) {
// parse and add the user model to the list
users.push( JSON.parse( value ) );
}
// pull the next key, if available
var key = keys.pop();
if (key) {
client.get( key, loopCallback );
} else {
// list is complete so return users, probably through a callback;
}
}
// start the loop
loopCallback();
This is a good general purpose solution, but there are others that use sorted sets that are move efficient when you want access to the entire list with each access. This solution gives you the ability to get a single user object when you know the ID.
I hope this helps.
ps: a full implementation with unit tests of this can be found in the AbstractBaseDao module of this project.
I'm using a new database from Microsoft called DocumentDB. Now I want to delete a document by ID, but I cannot figure out, how to do this. Delete operation in DocumentDB requires self-links and they are different from my own ids.
using (var client = new DocumentClient(EndPoint, AuthKey))
{
await client.DeleteDocumentAsync("**self-link here**");
}
I can execute an additional query to find the self-link and then pass it, but this will require two operations instead one and that is what I'd like to avoid. Is there a better way to remove an entry by ID without using queries or stored procedures?
* UPDATE * This feature has now been implemented
* ORIGINAL ANSWER *
Not today, no. You can head to http://feedback.azure.com/forums/263030-documentdb and vote for the feature there.
Here is how I am deleting document
{
var docUri = UriFactory.CreateDocumentUri(_documentDataBaseId, _documentCollectionId, docId);
await _documentClient.DeleteDocumentAsync(docUri);
}
This features has now been implement (as of the 8/2015 - https://feedback.azure.com/forums/263030-documentdb/suggestions/6333050-it-should-be-possible-to-remove-a-document-by-id
as there's no solution for this case I'd recommend to retrieve all the documents in the existing collection to get access to the SelfLink and _rid values.
I just started a mini wrapper to get access to DocumentDB in Universal Apps and hopefully CrossPlatform using Xamarin: https://github.com/JorgeCupi/documentDB-Win10UAP-wrapper feel free to give me any feedback, participate or request some needed methods.
I have tried this code in nodejs to deletebyId and it works for me.
deleteDocumentById: function(params, callback) {
var self = this,
query= params.query,
collection = params.collection;
client.queryDocuments(collection._self, query, function(err, docs) {
if (err) {
return callback(err);
}
client.deleteDocument(docs[0]._self, docs[0], function(err, success) {
if (err) {
return callback(err);
}
callback(null, success);
});
});
}
I was continuously receiving this error: Microsoft.Azure.Documents.DocumentClientException:
Entity with the specified id does not exist in the system.,
The main trick of deleting is PartionKey id. You suppose inside PartionKey provide id
like in the code example.
I have tried many ways, but I was always receiving different errors...Only this solution worked for me.
await client.DeleteDocumentAsync(input[0].SelfLink,
new RequestOptions
{
PartitionKey = new PartitionKey(input[0].Id)
});
Hope this helps :)