I'm developing an application in Quasar/Electron and using Dexie/IndexedDB for my database. I want to find all distinct records in the database that contain both my Event ID and a Dog ID (both key indexed fields). I am able to do this with the following code:
await myDB.runTable
.orderBy('[fk_event+fk_dog]')
.eachUniqueKey((theDuo) => {
this.runsArray.push({eventID: theDuo[0], dogID: theDuo[1]})
})
I'm using a combined key which is working well. However, I need to have more of the records than just the keys. I need a few more fields, is this possible?
I was trying to get records with the unique key function while also using the where function, but that doesn't seem to work.
I need to get all the unique (distinct?) dogs in the table that are in a particular event. And also get their corresponding information. I'm not sure if there is a better, more efficient way to do this? I can always pull out all the records and loop through them to build a custom array, I was just hoping to do this at the table read level. (yeah I'm still in tables/records even though these are collections etc. :p ).
Even the above code gives me all the events, and I can pull out what I need with a filter. I just was thinking it would be faster and more efficient to do it at the read level.
this.enteredRuns = this.runsArray.filter((theEvent) => {
return ( (theEvent.eventID == this.currentEventID) )
})
Try
await myDB.runTable
.orderBy('[fk_event+fk_dog]')
.clone({unique: "unique"})
.toArray()
I know this isn't documented but it should do the work to use unique cursor while still extracting the whole objects and not just the keys. You cannot combine with where but you could use .filter. Just be aware that not all records with be scanned as it will jump over records with same keys - selecting the first visited records only.
Related
I am creating a Social app and want to track if a username already exists or not. The username list is supposed to grow in future and the way I was doing it now was a key value pair of <string,bolean> like this:
name1: true,
name2: true
all the above data was to be stored in a single document and whenever I want to see if a user exists I would call this document and check accordingly. But here's the problem, firebase max document size is 1MBs and as the users grow this can be problematic, so wanted to know from firebase experts that what's the best way to solve this use case in firestore or realtime database but since I need to query exists maybe realtime db won't suit that well.
Note that I don't want any of firestore querying capabilities but only to check if an entry exists in the record or not and if not just add it.
The Realtime Database doesn't have a 1MB limit (since it has no concept of a document, and everything is just a tree of JSON), so I'd typically use that for the index of user names.
Checking whether a name exists is pretty simple there too, and in JavaScript would look something like:
const usernames = firebase.database().ref('usernames');
usernames.child('name1').once((snapshot) => {
if (snapshot.exists()) {
...
}
});
I have a plannerTask and in its Details it has a CheckList. I use it to programatically insert CheckListItems in it, and it all works like a charm when inserting or retrieving the tasks.
My problem arrives when I am going to insert a new CheckListItem and the CheckList already has 20 items. It returns a MaximumChecklistItemsOnTask (because it is forbidden to insert more than 20 items in a check list).
Solution could be to remove the oldest item, but I am not able to do it. I have tried this:
var elementToRemove = oldDetails.Checklist.Where(c => c.Value.IsChecked).OrderBy(c => c.Value.LastModifiedDateTime).First();
oldDetails.Checklist = oldDetails.Checklist.Where(c => c.Value.LastModifiedDateTime <> elementToRemove.Value.LastModifiedDateTime);
But it throws a casting error in the second line:
Unable to cast object of type
'WhereEnumerableIterator1[System.Collections.Generic.KeyValuePair2[System.String,Microsoft.Graph.PlannerChecklistItem]]'
to type 'Microsoft.Graph.PlannerChecklistItems'.
Which is the right way to remove the oldest element from the ChecklistItem?
UPDATE:
In first place I retrieve a plannerTask from the server. Then I get the details from this plannerTask. So oldDetails is a plannertaskdetails object (https://learn.microsoft.com/en-us/graph/api/resources/plannertaskdetails?view=graph-rest-1.0). Inside the plannertaskdetails object (oldDetails), I have the plannerchecklistitems object (oldDetails.Checklist): https://learn.microsoft.com/en-us/graph/api/resources/plannerchecklistitems?view=graph-rest-1.0.
If plannerchecklistitems were just a List, it would be as easy as list.Remove(item), but it is not a normal list, and that is why I am not able to remove the item.
UPDATE 2:
I have found this way to remove the item from oldDetails:
oldDetails.Checklist.AdditionalData.Remove(elementToRemove.Key)
But, the the way I send the changes to the server is this:
await graphClient.Planner.Tasks(plannerTask.Id).Details.Request().Header("If-Match", oldDetails.GetEtag).UpdateAsync(newDetails)
As it is a PATCH request (not a PUT one), I only have in newDetails the records that have changed, it is, the new records. How could I specify there that a record has been deleted from the list? Sorry if my English is not good enough to express myself properly, but what I mean is that newDetails is not the full list, it only contains the records that must be added and I do not know how to specify in that request that one record must be deleted.
Good afternoon fellow developers,
I have come across a scenario where I found myself needing to retrieve the list of pending changes from my model and editing a specific property of those entries before sending them to my back-end.
These are new entities I created using the createEntry() method of the OData model v2. But, at the time of creation of said entities, I do not possess the value I need to add to them yet. This is the list of entities I retrieve by using the getPendingChanges() method on my model:
What I need to do is to loop through each of these newly created entities and set a specific property into them before actually sending them to my back-end with the submitChanges() method. Bare in mind that these are entry objects created by the createEntry() method and exist only in my front-end until I am able to submit them with success.
Any ideas that might point me in the right direction? I look forward to reading from you!
I was able to solve this issue in the following way:
var oPendingChanges = this.model.getPendingChanges();
var aPathsPendingChanges = $.map(oPendingChanges, function(value, index) { return [index];});
aPathsPendingChanges.forEach(sPath => oModel.setProperty("/" + sPath + "/PropertyX","valueFGO"));
The first two instructions retrieve the entire list of pendingChanges objects and then builds an array of paths to each individual entry. I then use that array of paths to loop through my list of pending changes and edit into the property I want in each iteration of the loop. Special thanks to the folks at answers.sap for the guidance!
I'm struggling to work out how to retrieve the property values from a filter query in a CosmosDb stored procedure. I'm sure this must be relatively simple, but just can't seem to find the right combination.
var result = __.chain()
.filter(function(doc) {
return doc.id ==="1stDocId";
})
.map(function(doc) {
return {
id: doc.id,
propertyA: doc.propertyA
};
})
.value();
if(!result.isAccepted) throw new Error("The call was not accepted");
Using the above code, or similar, I'm wanting to retrieve the value of propertyA, and then use it in a second query, and so on.
Using response.setBody to return the value of result at this point, I can see it is sat in an array, but can't work out the correct code to access it.
result[0].PropertyA, result[0][0].PropertyA don't work, can someone point me in the right direction?
I'm able to do this sort of thing using the queryDocuments function, but ultimately my stored procedure needs to execute 5 or 6 select statements, manipulating the retrieved values in between. Utilising nested callbacks seems very messy, and pretty confusing once you're a few levels deep. Is there a better way?
Thanks.
Well I gave in, and wrote the procedure using nested callbacks and 'queryDocuments'. Since at one point my procedure requires a switch statement, which either performs a db lookup, or provides a hard value, I had to duplicate the rest of the queryDocument calls in the db lookup branch callback, which feels plain wrong.
However, whilst not being pretty, my stored procedure now works, returning the correct values in all cases.
I am new to learning and understanding how Hydration works, just wanted to point that out first. I'm currently able to Hydrate Select and Insert queries without any problems.
I am currently stuck on trying to Hydrate Update queries now. In my entity I have setup the get/set options for each type of column in my database. I've found that the ObjectProperty() Hydrator works best for my situation too.
However whenever I try to update only a set number of columns and extract via the hydrator I am getting errors because all the other options are not set and are returning null values. I do not need to update everything for a particular row, just a few columns.
For example in my DB Table I may have:
name
phone_number
email_address
But I only need to update the phone_number.
$entity_passport = $this->getEntityPassport();
$entity_passport->setPrimaryPhone('5551239876');
$this->getTablePassport()->update($this->getHydrator()->extract($entity_passport), array(
'employeeid' => '1'
));
This returns an error because setName() and setEmailAddress() are not included in this update and the query returns that the values cannot be null. But clearly when you look at the DB Table, there is data already there. The data that is there does not need to be changed either, only in this example does the PrimaryPhone() number.
I've been looking and reading documentation all over the place but I cannot find anything that would explain what I am doing wrong. I should note that I am only using Zend\Db (Not Doctrine).
I'm assuming I've missed something someplace due to my lack of knowledge with this new feature I'm trying to understand.
Perhaps you don't Hydrate Update queries... I'm sort of lost / confused. Any help would be appreciated. Thank you!
I think you're having a fundamental misconception of hydration. A hydrator simply populates an entity object from data (hydrate) and extracts data from an entity object (extract). So there are no separate hydrators for different types of queries.
In your update example you should first retrieve the complete entity object ($entity_passport) and then pass it to the TableGateway's update method. You would retrieve the entity by employeeid, since that's the condition you're using to update. So something like this:
$entity_passport = $passportMapper->findByEmployeeId(1);
$entity_passport->setPrimaryPhone('5551239876');
$this->getTablePassport()->update($this->getHydrator()->extract($entity_passport), array(
'employeeid' => $entity_passport->getId()
));
This is assuming you have some sort of mapper layer. Otherwise you could use your passport TableGateway (I assume that's what getTablePassport() returns, no?).
Otherwise, if you think retrieving the object is too much overhead and you just want to run the query you could use just a \Zend\Db\Sql\Sql object, ie:
$sql = new \Zend\Db\Sql\Sql($dbAdapter);
$update = $sql->update('passport')
->set(array('primary_phone' => $entity_passport->getPrimaryPhone()))
->where(array('employeeid' => $employeeId));
Edit:
Maybe it was a mistake to bring up the mapper, because it may cause more confusion. You could simply use your TableGateway to retrieve the entity object and then hydrate the returned row:
$rows = $this->getTablePassport()->select(array('employeeid' => 1));
$entity_passport = $this->getHydrator($rows->current());
[...]
Edit 2:
I checked your gist and I noticed a few things, so here we go:
I see that your getTablePassport indeed does return an object which is a subclass of TableGateway. You have already set up this class for it to use a HydratingResultset. This means you don't need to do any manual hydrating when retrieving objects using the gateway.
You also already implemented a Search method in that same class, so why not just use that? However I would change that method, because right now you're using LIKE for every single column. Not only is it very inefficient, but it will also give you wrong results, for example on the id column.
If you were to fix that method then you can simply call it in the Service object:
$this->getTablePassport->Search(array('employeeid' => 1));
Otherwise you could just implement a separate method in that tablegateway class, such as
public function findByEmployeeId($employeeId)
{
return $tableGateway->select(array('employeeid' => $employeeId));
}
This should already return an array of entities (or one in this specific case). P.S. make sure to debug and check what is actually being returned when you retrieve the entity. So print_r the entity you get back from the PassportTable before trying the update. You first have to make sure the retrieval code works well.