When I do a create using sequelize it returns me the response i.e. the newly created entry row in the response,
Sequelize Create Object Code:
let createdObj= await sequelize.ModelName.create(modelObject,{ transaction :t, //more options can be added here, need some value of option that prevents the output inserted })
Below is the query created:
INSERT INTO [TABLE_NAME] ([COL1],[COL2],[COL3],[COL4]) OUTPUT INSERTED.* VALUES (#0,#1,#2,#3,#4)
Now I don't want the output clause to be part of the query, I want a simple insert like:
INSERT INTO [TABLE_NAME] ([COL1],[COL2],[COL3],[COL4]) VALUES (#0,#1,#2,#3,#4)
I don't want the output clause to be part of the query.
How can I achieve this in at the query level as well as at the model level? In some Create operations, I want the output clause and in some create operations, I don't want.
EDIT 1
On Further research I found an option called { returning: false } this does what is required i.e. create an insert query like this INSERT INTO [TABLE_NAME] ([COL1],[COL2],[COL3],[COL4]) VALUES (#0,#1,#2,#3,#4) but now the Sequelize is breaking because it's expecting those values back in return idk why?
C:\Users\MG265X1\project\node_modules\sequelize\lib\dialects\mssql\query.js:389
id = id || results && results[0][this.getInsertIdField()];
^
TypeError: Cannot read property 'id' of undefined
at Query.handleInsertQuery (C:\Users\MG265X1\project\node_modules\sequelize\lib\dialects\mssql\query.js:389:39)
Turns out if an autoIncrementAttribute is present in the model, it will look for the output clause, removing the attribute {autoIncrement: true } from the model hasn't helped as IDENTITY_INSERT cannot be null. How do I move ahead on this??
Edit 2 I could get it working with a combination of { returning: false } and {hasTriggers: true}. Have hasTriggers Attribute as true in your Model, this will allow you to single creates but for bulk Creates pass option returning: false at the time of bulkCreate.
Note: When using bulkCreate with { returning: false } you'll not be able to get the autogenerated Id, It's a trade-off that we had to live with as we want
bulkCreate to work with triggers, we ended up fetching the Id later from DB
Seems I raised this issue but was closed as it wasn't good SSCCE
Im looking to do something that I would have thought was done so many times with Immutable.js Lists already but i can't seem to find this case. I have 2 lists. One with Items. And one that contains keys of the items selected as data. users who have selected things from items basically. I am storing the key from items as data in the profile of the user that selected the item (in a firebase db, not that it matters). So I want to simply filter the items in my app using a selector. In the selector Im looking to compare the key from items with the key I stored in the users profile.
If it's a match, then give me the matching data from items as state to use. I believe this should be a filter on Items of some kind?? To do the compare i also need to get the stored key data in the users profile to compare which is also a immutable list.
Im trying
const selectedItems = items.filter(
item => {
userItems.forEach(userItem => {
if (userItem.itemKey === item.key) {
return item <-------pretty sure this is where Im doing it wrong
}
})
});
If i hard code a record from my users profile and filter, I get what I expect which is new filtered list with one item matching the id below.
const selectedItems = items.filter(
item => {
return item.get('key') === '-LDR5cNZPjthN6nK9tzJ'
});
filter will create a new array with every element in the original array that returned a truthy value. With this in mind you could use a combination of filter and some to filter out all the objects you have a key for in userItems:
const selectedItems = items.filter(item =>
userItems.some(userItem => userItem.itemKey === item.itemKey)
);
I have an array named navLinks which has a property named requiredPermissions; also and an array of permission's which named userPermisssion.
Now I want to filter all navLink item based on that are them requiredPermission prop equal to requiredPermission.
My approach was simple, but I confused when it's come to list.
R.filter(R.equal(R.prop('requiredPermossions',x), ??? ))
EDIT:
for example, assume we have an array of objects named is NavLinks which has a property userPermisssion =['FIN'] and have a list requiredPermission=['FIN','ADMIN']. now we can say this user has permission for matching permissions navlinks. both variables are the list of string which indicates role and permissions.
I think I got what you need. It is cleaner to pipe the commands. Here goes an example that does what you want:
const navLinks = [
{ requiredPermissions: ['FIN'] },
{ requiredPermissions: ['FIN', 'ADMIN'] },
];
const userPermissions = ['FIN'];
const result = R.filter(
R.pipe(
R.prop('requiredPermissions'),
R.all(R.flip(R.contains)(userPermissions)),
), navLinks);
The explanation goes like this:
The function used in filter is called with each object in navLinks
Inside the pipe we keep only the requiredPermissions list
For each item in the list we check if it is included in the userPermissions list. Only if all the permissions are included in userPermissions do we return true.
Explanation
I have a very simple calorie tracking app that uses the Nutritionix API to search for food items based on the user's input. The results are added to a results array, which is then displayed to the user. When a user clicks the "Add" button next to one of these items, the calories are added to a counter, and the food itself is added to a todaysFood array (using Ember's pushObject). This is then used to display which food the user has consumed today in a separate table.
When a user clicks the remove button next to one of the todaysFood items, it triggers an action, removeItem, and passes the index of the item clicked to removeItem. This index is used inside of Ember's removeObject to remove the item from the todaysFood array, and thus update the view (remove that item from the list and its calories from the counter).
Problem
When more than one of the same item are added to todaysFood, clicking remove on just one of those items removes ALL of the instances from todaysFood, and the view. This makes sense to me now, because of the docs' example:
var cities = ['Chicago', 'Berlin', 'Lima', 'Chicago'];
cities.removeObject('Chicago'); // ['Berlin', 'Lima']
cities.removeObject('Lima'); // ['Berlin']
cities.removeObject('Tokyo') // ['Berlin']
However, it also only removes the calories of ONE item, not all instances.
So, the question is: How do I remove only ONE instance of that item when remove is clicked? I.e., if two tacos are added, and I click remove on one, I only want that ONE to be removed (from the list and the calories).
Here is my removeItem action:
removeItem(index) {
var self = this;
// Store property paths for easy access
let todaysPath = this.get('healthData').todaysFood;
let caloriesPath = 'healthData.calories';
this.set(caloriesPath, this.get(caloriesPath) - Math.round(todaysPath[index].fields.nf_calories));
todaysPath.removeObject(todaysPath[index]);
}
Disclaimer
I'm aware that I may not be handling this correctly at all. I'm open to any suggestions to make this better. Thanks!
You have index of object to remove so you can try using removeAt() method:
todaysPath.removeAt(index);
I'm trying to test out Firebase to allow users to post comments using push. I want to display the data I retrieve with the following;
fbl.child('sell').limit(20).on("value", function(fbdata) {
// handle data display here
}
The problem is the data is returned in order of oldest to newest - I want it in reversed order. Can Firebase do this?
Since this answer was written, Firebase has added a feature that allows ordering by any child or by value. So there are now four ways to order data: by key, by value, by priority, or by the value of any named child. See this blog post that introduces the new ordering capabilities.
The basic approaches remain the same though:
1. Add a child property with the inverted timestamp and then order on that.
2. Read the children in ascending order and then invert them on the client.
Firebase supports retrieving child nodes of a collection in two ways:
by name
by priority
What you're getting now is by name, which happens to be chronological. That's no coincidence btw: when you push an item into a collection, the name is generated to ensure the children are ordered in this way. To quote the Firebase documentation for push:
The unique name generated by push() is prefixed with a client-generated timestamp so that the resulting list will be chronologically-sorted.
The Firebase guide on ordered data has this to say on the topic:
How Data is Ordered
By default, children at a Firebase node are sorted lexicographically by name. Using push() can generate child names that naturally sort chronologically, but many applications require their data to be sorted in other ways. Firebase lets developers specify the ordering of items in a list by specifying a custom priority for each item.
The simplest way to get the behavior you want is to also specify an always-decreasing priority when you add the item:
var ref = new Firebase('https://your.firebaseio.com/sell');
var item = ref.push();
item.setWithPriority(yourObject, 0 - Date.now());
Update
You'll also have to retrieve the children differently:
fbl.child('sell').startAt().limitToLast(20).on('child_added', function(fbdata) {
console.log(fbdata.exportVal());
})
In my test using on('child_added' ensures that the last few children added are returned in reverse chronological order. Using on('value' on the other hand, returns them in the order of their name.
Be sure to read the section "Reading ordered data", which explains the usage of the child_* events to retrieve (ordered) children.
A bin to demonstrate this: http://jsbin.com/nonawe/3/watch?js,console
Since firebase 2.0.x you can use limitLast() to achieve that:
fbl.child('sell').orderByValue().limitLast(20).on("value", function(fbdataSnapshot) {
// fbdataSnapshot is returned in the ascending order
// you will still need to order these 20 items in
// in a descending order
}
Here's a link to the announcement: More querying capabilities in Firebase
To augment Frank's answer, it's also possible to grab the most recent records--even if you haven't bothered to order them using priorities--by simply using endAt().limit(x) like this demo:
var fb = new Firebase(URL);
// listen for all changes and update
fb.endAt().limit(100).on('value', update);
// print the output of our array
function update(snap) {
var list = [];
snap.forEach(function(ss) {
var data = ss.val();
data['.priority'] = ss.getPriority();
data['.name'] = ss.name();
list.unshift(data);
});
// print/process the results...
}
Note that this is quite performant even up to perhaps a thousand records (assuming the payloads are small). For more robust usages, Frank's answer is authoritative and much more scalable.
This brute force can also be optimized to work with bigger data or more records by doing things like monitoring child_added/child_removed/child_moved events in lieu of value, and using a debounce to apply DOM updates in bulk instead of individually.
DOM updates, naturally, are a stinker regardless of the approach, once you get into the hundreds of elements, so the debounce approach (or a React.js solution, which is essentially an uber debounce) is a great tool to have.
There is really no way but seems we have the recyclerview we can have this
query=mCommentsReference.orderByChild("date_added");
query.keepSynced(true);
// Initialize Views
mRecyclerView = (RecyclerView) view.findViewById(R.id.recyclerView);
mManager = new LinearLayoutManager(getContext());
// mManager.setReverseLayout(false);
mManager.setReverseLayout(true);
mManager.setStackFromEnd(true);
mRecyclerView.setHasFixedSize(true);
mRecyclerView.setLayoutManager(mManager);
I have a date variable (long) and wanted to keep the newest items on top of the list. So what I did was:
Add a new long field 'dateInverse'
Add a new method called 'getDateInverse', which just returns: Long.MAX_VALUE - date;
Create my query with: .orderByChild("dateInverse")
Presto! :p
You are searching limitTolast(Int x) .This will give you the last "x" higher elements of your database (they are in ascending order) but they are the "x" higher elements
if you got in your database {10,300,150,240,2,24,220}
this method:
myFirebaseRef.orderByChild("highScore").limitToLast(4)
will retrive you : {150,220,240,300}
In Android there is a way to actually reverse the data in an Arraylist of objects through the Adapter. In my case I could not use the LayoutManager to reverse the results in descending order since I was using a horizontal Recyclerview to display the data. Setting the following parameters to the recyclerview messed up my UI experience:
llManager.setReverseLayout(true);
llManager.setStackFromEnd(true);
The only working way I found around this was through the BindViewHolder method of the RecyclerView adapter:
#Override
public void onBindViewHolder(final RecyclerView.ViewHolder holder, int position) {
final SuperPost superPost = superList.get(getItemCount() - position - 1);
}
Hope this answer will help all the devs out there who are struggling with this issue in Firebase.
Firebase: How to display a thread of items in reverse order with a limit for each request and an indicator for a "load more" button.
This will get the last 10 items of the list
FBRef.child("childName")
.limitToLast(loadMoreLimit) // loadMoreLimit = 10 for example
This will get the last 10 items. Grab the id of the last record in the list and save for the load more functionality. Next, convert the collection of objects into and an array and do a list.reverse().
LOAD MORE Functionality: The next call will do two things, it will get the next sequence of list items based on the reference id from the first request and give you an indicator if you need to display the "load more" button.
this.FBRef
.child("childName")
.endAt(null, lastThreadId) // Get this from the previous step
.limitToLast(loadMoreLimit+2)
You will need to strip the first and last item of this object collection. The first item is the reference to get this list. The last item is an indicator for the show more button.
I have a bunch of other logic that will keep everything clean. You will need to add this code only for the load more functionality.
list = snapObjectAsArray; // The list is an array from snapObject
lastItemId = key; // get the first key of the list
if (list.length < loadMoreLimit+1) {
lastItemId = false;
}
if (list.length > loadMoreLimit+1) {
list.pop();
}
if (list.length > loadMoreLimit) {
list.shift();
}
// Return the list.reverse() and lastItemId
// If lastItemId is an ID, it will be used for the next reference and a flag to show the "load more" button.
}
I'm using ReactFire for easy Firebase integration.
Basically, it helps me storing the datas into the component state, as an array. Then, all I have to use is the reverse() function (read more)
Here is how I achieve this :
import React, { Component, PropTypes } from 'react';
import ReactMixin from 'react-mixin';
import ReactFireMixin from 'reactfire';
import Firebase from '../../../utils/firebaseUtils'; // Firebase.initializeApp(config);
#ReactMixin.decorate(ReactFireMixin)
export default class Add extends Component {
constructor(args) {
super(args);
this.state = {
articles: []
};
}
componentWillMount() {
let ref = Firebase.database().ref('articles').orderByChild('insertDate').limitToLast(10);
this.bindAsArray(ref, 'articles'); // bind retrieved data to this.state.articles
}
render() {
return (
<div>
{
this.state.articles.reverse().map(function(article) {
return <div>{article.title}</div>
})
}
</div>
);
}
}
There is a better way. You should order by negative server timestamp. How to get negative server timestamp even offline? There is an hidden field which helps. Related snippet from documentation:
var offsetRef = new Firebase("https://<YOUR-FIREBASE-APP>.firebaseio.com/.info/serverTimeOffset");
offsetRef.on("value", function(snap) {
var offset = snap.val();
var estimatedServerTimeMs = new Date().getTime() + offset;
});
To add to Dave Vávra's answer, I use a negative timestamp as my sort_key like so
Setting
const timestamp = new Date().getTime();
const data = {
name: 'John Doe',
city: 'New York',
sort_key: timestamp * -1 // Gets the negative value of the timestamp
}
Getting
const ref = firebase.database().ref('business-images').child(id);
const query = ref.orderByChild('sort_key');
return $firebaseArray(query); // AngularFire function
This fetches all objects from newest to oldest. You can also $indexOn the sortKey to make it run even faster
I had this problem too, I found a very simple solution to this that doesn't involved manipulating the data in anyway. If you are rending the result to the DOM, in a list of some sort. You can use flexbox and setup a class to reverse the elements in their container.
.reverse {
display: flex;
flex-direction: column-reverse;
}
myarray.reverse(); or this.myitems = items.map(item => item).reverse();
I did this by prepend.
query.orderByChild('sell').limitToLast(4).on("value", function(snapshot){
snapshot.forEach(function (childSnapshot) {
// PREPEND
});
});
Someone has pointed out that there are 2 ways to do this:
Manipulate the data client-side
Make a query that will order the data
The easiest way that I have found to do this is to use option 1, but through a LinkedList. I just append each of the objects to the front of the stack. It is flexible enough to still allow the list to be used in a ListView or RecyclerView. This way even though they come in order oldest to newest, you can still view, or retrieve, newest to oldest.
You can add a column named orderColumn where you save time as
Long refrenceTime = "large future time";
Long currentTime = "currentTime";
Long order = refrenceTime - currentTime;
now save Long order in column named orderColumn and when you retrieve data
as orderBy(orderColumn) you will get what you need.
just use reverse() on the array , suppose if you are storing the values to an array items[] then do a this.items.reverse()
ref.subscribe(snapshots => {
this.loading.dismiss();
this.items = [];
snapshots.forEach(snapshot => {
this.items.push(snapshot);
});
**this.items.reverse();**
},
For me it was limitToLast that worked. I also found out that limitLast is NOT a function:)
const query = messagesRef.orderBy('createdAt', 'asc').limitToLast(25);
The above is what worked for me.
PRINT in reverse order
Let's think outside the box... If your information will be printed directly into user's screen (without any content that needs to be modified in a consecutive order, like a sum or something), simply print from bottom to top.
So, instead of inserting each new block of content to the end of the print space (A += B), add that block to the beginning (A = B+A).
If you'll include the elements as a consecutive ordered list, the DOM can put the numbers for you if you insert each element as a List Item (<li>) inside an Ordered Lists (<ol>).
This way you save space from your database, avoiding unnecesary reversed data.