How to create this JSON response? - arrays

I'm trying to Create a specific Syntax for POST Request.
That is, using Javascript to Create the specified Array Structure based on certain data.
Data : Array of Objects. Each Object represents a row in a Table.
Those rows, have an ID Key, that can be found on More that one Row.
POST Request : Create the Below POST Request Syntax:
For Each Unique Row ID, create the P1 Section. (This Object Represents each Unique ID )
If ID is entered more that once, do not create more P1 Sections with same ID. P1 is already created for this ID.
For each of these unique IDs, get its Row Details and place them in Section P2.
If Unique IDs rows are more that one, create multiple P2 Sections for the Specific ID.
[
[
P1 - {
"Swee": "Cont",
"Time": 33,
"ID": 10,
"Configs": [
P2 - {
"VAL": "VALUE"
P2 - }
]
P1 - }
]
]
Please, anyone can help please do.

I would recommend the following:
1. Iterate over your data and filter what you need, simplest is to use lodash try this method for your needs: https://lodash.com/docs/4.17.11#uniqBy
2. You can deconstruct properties and elements from an object or array like this this:
const { property1, property2, property3 } = this.myData this exposes these properties from your data (stored in myData in this example), now you can restructure them as you wish for example:
paylod : { property1: { property2 }, property3 } here my payload object now has a new nested structure. In your question you do not provide enough info for me to do this but this would be a direction to take. Hope this helps

Related

HTTP Request logic app - parse values from array name, value pair

I am POSTing valid JSON to a logic app and the request body is a simple set of name/value pairs in JSON format. I use parse JSON action to turn the JSON into a variable. (I am not sure if this is absolutely required, or if I can reference the http body directly without a JSON object).
[
{
"name": "fullname",
"value": "joe schmoe"
},
{
"name": "email",
"value": "joeschmoe#acme.com"
}
]
All I need to do (and this is driving me nuts) is create two variables, one containing the value of the email field and one containing the value of the fullname field.
As soon as I try to use the output value value, the logic app replaces my action with a For Each action, and then I try to to assign item().value[0] or item().value[1] to a variable without luck.
I have read dozens of examples online, but of course they all seem to be parsing JSON where there is largely unique elements in the name:value pairs.
While this is a bit of a newb question, I'm confused and need advice.
Thank you.
I used a parseJSON action to ensure I have a varaible containing the JSON array.
I then referenced the array value with (explained):
"from the body of the output from the Parse JSON action, refernce the first record in the set (fullname) and then the value of that record, the value 'joe schmoe'"
#{body('Parse_JSON')[0]['value']} (returns fullname)
Email is similar, just 2nd record in the collection:
#{body('Parse_JSON')[1]['value']} (returns email address)

How do I import my JSON array into Firebase as a FirebaseArray?

I have a large JSON file which contains an array. I am using Firebase for my app's backend and I want to use FirebaseArray to store the data.
It is simple to create a FirebaseArray from my Angular app and add data to it, but the nature of my app is that I have fetched data which I need to first import into Firebase somehow.
On the Firebase website the only option for importing is from a JSON. When I import my JSON file, the result is an object with numerical keys, which I realize is like an array, but has a major issue.
{
"posts": {
"0": {
"id": "iyo0iw",
"title": "pro patria mori"
},
"1": {
"id": "k120iw",
"title": "an english title"
},
"2": {
"id": "p6124w",
"title": "enim pablo espa"
}
}
}
Users are able to change the position of items, and the position of an item is also how items are uniquely identified. With multiple users this means the following problem can occur.
Sarah: Change post[0] title to "Hello everyone"
Trevor: Swap post[1] position with post[2]
Sarah: Change post[1] title to "This is post at index 1 right?"
If the following actions happen in a short space of time, Firebase doesn't know for sure what Sarah saw as post[1] when they changed the title, and can't know for sure which post object to update.
What I want is a way to import my JSON file and have the arrays become FirebaseArrays, not objects with numerical keys, which are like arrays and share the issue described above.
What you imported into your database is, in fact, an array. Firebase Realtime Database only really represents data as a nested hierarchy of key/value pairs. An array is just a set of key/value pairs where the the keys are all numbers, typically starting at 0. That's exactly the structure you're showing in your question.
To generate the sort of data that would be created by writing to the database using an AngularFire FirebaseArray, you would need to pre-process your JSON.
Firebase push IDs are generated on the client and you can generate one by calling push without arguments.
You could convert an array to an object with Firebase push ID keys like this:
let arr = ["alice", "bob", "mallory"];
let obj = arr.reduce((acc, val) => {
let key = firebase.database().ref().push().key;
acc[key] = val;
return acc;
}, {});

Angular alphabetizes GET response

I am currently trying to make an interactive table in Angular that reflects table information from a SQL database.
The stack I am using is MSSQL, Express.js, and AngularJS. When I log the response in Node, the data is in the desired order. However, when I log the data from .success(function(data)), the fields are alphabetized and the rows are put in random order).
I am sending a JSON object (an array of rows EX. {"b":"blah","a":"aye"}). However the row is received in Angular as {"a":"aye","b":"blah"}.
Desired affect -> Use column and row ordering from SQL query in client view. Remove "magic" angular is using to order information.
In Javascript, the properties of an object do not have guaranteed order. You need to send a JSON array instead:
["blah", "aye"]
If you need the column names as well you can send down an array of objects:
[{ "col":"b", "value":"blah" }, { "col":"a", "value":"aye" }]
Or alternatively, an object of arrays:
{ "col": ["b", "a"], "value": ["blah", "aye"] }
Edit: After some more thought, you're ideal JSON structure would probably look like this:
{
"col": ["b","a"],
"row": [
["blah","aye"],
["second","row"],
["and","so on"]
]
}
Now instead of getting "blah" from accessing table[0]['b'] like you would've before, you'll need to do something like table.row[0][table.col.indexOf('b')]

MongoDB: Query and retrieve objects inside embedded array?

Let's say I have the following document schema in a collection called 'users':
{
name: 'John',
items: [ {}, {}, {}, ... ]
}
The 'items' array contains objects in the following format:
{
item_id: "1234",
name: "some item"
}
Each user can have multiple items embedded in the 'items' array.
Now, I want to be able to fetch an item by an item_id for a given user.
For example, I want to get the item with id "1234" that belong to the user with name "John".
Can I do this with mongoDB? I'd like to utilize its powerful array indexing, but I'm not sure if you can run queries on embedded arrays and return objects from the array instead of the document that contains it.
I know I can fetch users that have a certain item using {users.items.item_id: "1234"}. But I want to fetch the actual item from the array, not the user.
Alternatively, is there maybe a better way to organize this data so that I can easily get what I want? I'm still fairly new to mongodb.
Thanks for any help or advice you can provide.
The question is old, but the response has changed since the time. With MongoDB >= 2.2, you can do :
db.users.find( { name: "John"}, { items: { $elemMatch: { item_id: "1234" } } })
You will have :
{
name: "John",
items:
[
{
item_id: "1234",
name: "some item"
}
]
}
See Documentation of $elemMatch
There are a couple of things to note about this:
1) I find that the hardest thing for folks learning MongoDB is UN-learning the relational thinking that they're used to. Your data model looks to be the right one.
2) Normally, what you do with MongoDB is return the entire document into the client program, and then search for the portion of the document that you want on the client side using your client programming language.
In your example, you'd fetch the entire 'user' document and then iterate through the 'items[]' array on the client side.
3) If you want to return just the 'items[]' array, you can do so by using the 'Field Selection' syntax. See http://www.mongodb.org/display/DOCS/Querying#Querying-FieldSelection for details. Unfortunately, it will return the entire 'items[]' array, and not just one element of the array.
4) There is an existing Jira ticket to add this functionality: it is https://jira.mongodb.org/browse/SERVER-828 SERVER-828. It looks like it's been added to the latest 2.1 (development) branch: that means it will be available for production use when release 2.2 ships.
If this is an embedded array, then you can't retrieve its elements directly. The retrieved document will have form of a user (root document), although not all fields may be filled (depending on your query).
If you want to retrieve just that element, then you have to store it as a separate document in a separate collection. It will have one additional field, user_id (can be part of _id). Then it's trivial to do what you want.
A sample document might look like this:
{
_id: {user_id: ObjectId, item_id: "1234"},
name: "some item"
}
Note that this structure ensures uniqueness of item_id per user (I'm not sure you want this or not).

mongodb - retrieve array subset

what seemed a simple task, came to be a challenge for me.
I have the following mongodb structure:
{
(...)
"services": {
"TCP80": {
"data": [{
"status": 1,
"delay": 3.87,
"ts": 1308056460
},{
"status": 1,
"delay": 2.83,
"ts": 1308058080
},{
"status": 1,
"delay": 5.77,
"ts": 1308060720
}]
}
}}
Now, the following query returns whole document:
{ 'services.TCP80.data.ts':{$gt:1308067020} }
I wonder - is it possible for me to receive only those "data" array entries matching $gt criteria (kind of shrinked doc)?
I was considering MapReduce, but could not locate even a single example on how to pass external arguments (timestamp) to Map() function. (This feature was added in 1.1.4 https://jira.mongodb.org/browse/SERVER-401)
Also, there's always an alternative to write storedJs function, but since we speak of large quantities of data, db-locks can't be tolerated here.
Most likely I'll have to redesign the structure to something 1-level deep, like:
{
status:1,delay:3.87,ts:138056460,service:TCP80
},{
status:1,delay:2.83,ts:1308058080,service:TCP80
},{
status:1,delay:5.77,ts:1308060720,service:TCP80
}
but DB will grow dramatically, since "service" is only one of many options which will append each document.
please advice!
thanks in advance
In version 2.1 with the aggregation framework you are now able to do this:
1: db.test.aggregate(
2: {$match : {}},
3: {$unwind: "$services.TCP80.data"},
4: {$match: {"services.TCP80.data.ts": {$gte: 1308060720}}}
5: );
You can use a custom criteria in line 2 to filter the parent documents. If you don't want to filter them, just leave line 2 out.
This is not currently supported. By default you will always receive the whole document/array unless you use field restrictions or the $slice operator. Currently these tools do not allow filtering the array elements based on the search criteria.
You should watch this request for a way to do this: https://jira.mongodb.org/browse/SERVER-828
I'm attempting to do something similar. I tried your suggestion of using the GROUP function, but I couldn't keep the embedded documents separate or was doing something incorrectly.
I needed to pull/get a subset of embedded documents by ID. Here's how I did it using Map/Reduce:
db.parent.mapReduce(
function(parent_id, child_ids){
if(this._id == parent_id)
emit(this._id, {children: this.children, ids: child_ids})
},
function(key, values){
var toReturn = [];
values[0].children.forEach(function(child){
if(values[0].ids.indexOf(product._id.toString()) != -1)
toReturn.push(child);
});
return {children: toReturn};
},
{
mapparams: [
"4d93b112c68c993eae000001", //example parent id
["4d97963ec68c99528d000007", "4debbfd5c68c991bba000014"] //example embedded children ids
]
}
).find()
I've abstracted my collection name to 'parent' and it's embedded documents to 'children'. I pass in two parameters: The parent document ID and an array of the embedded document IDs that I want to retrieve from the parent. Those parameters are passed in as the third parameter to the mapReduce function.
In the map function I find the parent document in the collection (which I'm pretty sure uses the _id index) and emit its id and children to the reduce function.
In the reduce function, I take the passed in document and loop through each of the children, collecting the ones with the desired ID. Looping through all the children is not ideal, but I don't know of another way to find by ID on an embedded document.
I also assume in the reduce function that there is only one document emitted since I'm searching by ID. If you expect more than one parent_id to match, than you will have to loop through the values array in the reduce function.
I hope this helps someone out there, as I googled everywhere with no results. Hopefully we'll see a built in feature soon from MongoDB, but until then I have to use this.
Fadi, as for "keeping embedded documents separate" - group should handle this with no issues
function getServiceData(collection, criteria) {
var res=db[collection].group({
cond: criteria,
initial: {vals:[],globalVar:0},
reduce: function(doc, out) {
if (out.globalVar%2==0)
out.vals.push({doc.whatever.kind.and.depth);
out.globalVar++;
},
finalize: function(out) {
if (vals.length==0)
out.vals='sorry, no data';
return out.vals;
}
});
return res[0];
};

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