This question already has answers here:
Flutter: Update specific index in list (Firestore)
(2 answers)
Closed 2 years ago.
I need some help in flutter and firestore. I have an object inside an array in my collocation Is there any way to update object custom an array?
You can access and update anything inside an array by accessing it like you would any other array:
final List<SomeObject> _someObjects = <SomeObject>[];
...
for SomeObject s in _someObjects)
doSomethingWith(s);
Related
This question already has answers here:
PostgreSQL where all in array
(9 answers)
Closed 2 years ago.
In PostgreSQL IN can be used to match any value in a list. What if I need to match all values in a list? Is there a way to do this in PostgreSQL?
try = ALL (subquery) instead of IN (see manual)
This question already has answers here:
Removing duplicate elements from an array in Swift
(49 answers)
How to merge two custom type arrays and remove duplicate custom type items in Swift?
(2 answers)
Remove objects with duplicate properties from Swift array
(16 answers)
Closed 3 years ago.
I have an array of custom objects, a.k.a users, and some of them are duplicates.
How can I make sure there is only one of each element? No duplicates.
Also, what's the most efficient way?
var users: UserModel = [UserModel]()
Most efficient way if you don’t care about maintaining the original order in the array
let uniqueUsers = Array(Set(users))
Maybe instead of using an array you want to use a set? https://developer.apple.com/documentation/swift/set
This question already has answers here:
How to delete documents by query efficiently in mongo?
(5 answers)
Remove only one document in MongoDB
(9 answers)
Closed 4 years ago.
I have a simple action I'm trying to take to delete a single record in my db. I'm following the instructions to the letter:
db.users.deleteOne({login:"theUsersName"})
But for some reason I'm getting the following error:
TypeError: Property 'deleteOne' of object synctup.users is not a function
What am I missing here????
This question already has answers here:
Why this update query only update one record once
(3 answers)
Closed 7 years ago.
I'm a beginner in MongoDb.I wanted to know what is the query to remove a field in Mongo DB Collection.I have tried with
db.Component.update({},{$unset: {vendor:""}}).
Its was updating only first document.So How to remove field Completely from Collection?
Try this-db.Component.update({},{$unset: {vendor:""}},false,true)
Here false
This question already has answers here:
How to find the index array of a array of elements?
(3 answers)
Closed 8 years ago.
There are two arrays:
A=[2,6,9,10];
B=[6,10,9,2,2,9,10,10,6,6,2,9];
I want to output the following array:
C=[2,4,3,1,1,3,4,4,2,2,1,3];
How to do this work?
I found the solution, [~,C]=ismember(B,A);
My answer shall be C=arrayfun(#(x) find(A==x),B)