I want groupBy of famousAs of this data.
I got my data from api something like this
Personality:[
0: {
"FullName":"Harry Potter",
"DateOfBirth": "2020/02/16",
"Department":"Branch Operation",
"BirthDay":"Friday"
"famousAs":"Actor"
},
1: {
"FullName":"John Wick",
"DateOfBirth": "2020/02/16",
"Department":"Finance",
"BirthDay":"Friday"
"famousAs":"Actor"
},
2: {
"FullName":"Priyanka Chopara",
"DateOfBirth":2020/02/19,
"Department":"Loan",
"BirthDay":"Monday"
"famousAs":"Actress"
}
]
when i check ,type of this data then it is showing List of dynamic
If your want to group list of data according to their property value.
You can use .where() method to filter out the list.
List filter(List items, String value) =>
items.where((element) => element['famousAs'] == value).toList();
First the api response data from your question is invalid.
If your List is same as following above filter function will work fine.
or if your api response is HashMap change to Map first
[
{
"FullName": "Harry Potter",
"DateOfBirth": "2020/02/16",
"Department": "Branch Operation",
"BirthDay": "Friday",
"famousAs": "Actor"
},
{
"FullName": "John Wick",
"DateOfBirth": "2020/02/16",
"Department": "Finance",
"BirthDay": "Friday",
"famousAs": "Actor"
},
{
"FullName": "Priyanka Chopara",
"DateOfBirth": 2020 / 02 / 19,
"Department": "Loan",
"BirthDay": "Monday",
"famousAs": "Actress"
}
]
Usage..
final actors = filter(items, 'Actor');
final actresses = filter(items, 'Actress');
Related
I have this payload that I need to send to a server
"members": [
{
"names": "ben",
"date-of-birth": "1978-01-01",
"gender": "Male",
"surname": "surname",
"role": "Partner",
"total-cut": "100.00"
}
],
Only thing is at times there are no members, and following this am not supposed to send the array at all, it should just be nothing at all, no members.
For clarification, this is an example only, think there is a members object, like the above, schools object, courses object, only at times some of this come up empty and consequently I should omit the empty object entirely.
For example, in the below, if there are no members,,
{
"members": [
{
"names": "ben",
"date-of-birth": "1978-01-01",
"gender": "Male",
"surname": "surname",
"role": "Partner",
"total-cut": "100.00"
}
],
"courses": [
{
"name": "ben",
"number": "32",
"teacher": "Russ",
"cut": "10.00"
}
],
}
how can i create a conditional that omits the members and leaves courses only
{
"courses": [
{
"name": "ben",
"number": "32",
"teacher": "Russ",
"cut": "10.00"
}
],
}
For context this is a post request
I don't know if this has been solved or not yet (I hope yes :P). But this is a practical approach for reference in case others do run into a similar issue.
Problem
Before, here is a problem rephrasing just to make sure we are on the same line. If you have members, add them to the map otherwise no. In both these conditions the map should look like this:
// With members
{
"members": [
{
"names": "member_name",
//...
}
],
"courses": [
{
"name": "course_name",
//...
}
],
}
// Without members
{
"courses": [
{
"name": "course_name",
//...
}
],
}
Solution
In my opinion, the best way to handle this is to declare an empty Map() and conditionally add entries to it as fellows:
Map<String, dynamic> buildMyMap(){
final buffer = <String, dynamic>{};
if(members.isNotEmpty){
// Option 1
buffer.addEntries(MapEntry("members", members));
// Option 2
buffer["members"] = members;
}else{
// (Optional) In case you want to delete pre-existing members
buffer.remove("members");
}
if(courses.isNotEmpty){
// Option 1
buffer.addEntries(MapEntry("courses", courses));
// Option 2
buffer["courses"] = courses;
}else{
// (Optional) in case you want to remove pre-existing courses!
buffer.remove('courses');
}
return buffer;
}
You should declare the parameter members to be optional in your API, then you have no need to send this parameter.
you can do the following
final List members = [];
final List courses = [];
final map = {
if (members.isNotEmpty)
'members': [
for (final member in members)
{
"names": "ben",
"date-of-birth": "1978-01-01",
"gender": "Male",
"surname": "surname",
"role": "Partner",
"total-cut": "100.00"
}
],
if (courses.isNotEmpty)
'courses': [
for (final course in courses)
{
"name": "ben",
"number": "32",
"teacher": "Russ",
"cut": "10.00"
}
]
};
you can use if statement inside a map or a list in flutter,
also, if you want to multiple fields if a condition is met
final map2 = {
if(true)...{
'name': 'name',
'age': '12'
} else ...{
'name': 'NO NAME',
'age': 'NO AGE'
}
};
I have the JSON below in mongodb and would like write a bson.M filter to get a specific JSON in collection.
JSONs in collection:
{
"Id": "3fa85f64",
"Type": "DDD",
"Status": "PRESENT",
"List": [{
"dd": "55",
"cc": "33"
}],
"SeList": {
"comm_1": {
"seId": "comm_1",
"serName": "nmf-comm"
},
"comm_2": {
"seId": "comm_2",
"serName": "aut-comm"
}
}
}
{
"Id": "3fa8556",
"Type": "CCC",
"Status": "PRESENT",
"List": [{
"dd": "22",
"cc": "34"
}],
"SeList": {
"dnn_1": {
"seId": "dnn_1",
"serName": "dnf-comm"
},
"dnn_2": {
"seId": "dnn_2",
"serName": "dn2-comm"
}
}
}
I have written below the bson.M filter to select the first JSON but did not work because I do not know how to handle the map keys in the "SeList.serName". The keys comm_1, comm_2, dnn_1, etc could be any string.
filter := bson.M{"Type": DDD, "Status": "PRESENT", "SeList.serName": nmf-comm} // does not work because the "SeList.serName" is not correct.
I need help about how to select any JSON based on the example filter above.
I had to change one of the fields of my collection in mongoDB from an object to array of objects containing a lot of data. New documents get inserted without any problem, but when attempted to get old data, it never maps to the original DTO correctly and runs into errors.
subject is the field that was changed in Students collection.
I was wondering is there any way to update all the records so they all have the same data type, without losing any data.
The old version of Student:
{
"_id": "5fb2ae251373a76ae58945df",
"isActive": true,
"details": {
"picture": "http://placehold.it/32x32",
"age": 17,
"eyeColor": "green",
"name": "Vasquez Sparks",
"gender": "male",
"email": "vasquezsparks#orbalix.com",
"phone": "+1 (962) 512-3196",
"address": "619 Emerald Street, Nutrioso, Georgia, 6576"
},
"subject":
{
"id": 0,
"name": "math",
"module": {
"name": "Advanced",
"semester": "second"
}
}
}
This needs to be updated to the new version like this:
{
"_id": "5fb2ae251373a76ae58945df",
"isActive": true,
"details": {
"picture": "http://placehold.it/32x32",
"age": 17,
"eyeColor": "green",
"name": "Vasquez Sparks",
"gender": "male",
"email": "vasquezsparks#orbalix.com",
"phone": "+1 (962) 512-3196",
"address": "619 Emerald Street, Nutrioso, Georgia, 6576"
},
"subject": [
{
"id": 0,
"name": "math",
"module": {
"name": "Advanced",
"semester": "second"
}
},
{
"id": 1,
"name": "history",
"module": {
"name": "Basic",
"semester": "first"
}
},
{
"id": 2,
"name": "English",
"module": {
"name": "Basic",
"semester": "second"
}
}
]
}
I understand there might be a way to rename old collection, create new and insert data based on old one in to new one. I was wondering for some direct way.
The goal is to turn subject into an array of 1 if it is not already an array, otherwise leave it alone. This will do the trick:
update args are (predicate, actions, options).
db.foo.update(
// Match only those docs where subject is an object (i.e. not turned into array):
{$expr: {$eq:[{$type:"$subject"},"object"]}},
// Actions: set subject to be an array containing $subject. You MUST use the pipeline version
// of the update actions to correctly substitute $subject in the expression!
[ {$set: {subject: ["$subject"] }} ],
// Do this for ALL matches, not just first:
{multi:true});
You can run this converter over and over because it will ignore converted docs.
If the goal is to convert and add some new subjects, preserving the first one, then we can set up the additional subjects and concatenate them into one array as follows:
var mmm = [ {id:8, name:"CORN"}, {id:9, name:"DOG"} ];
rc = db.foo.update({$expr: {$eq:[{$type:"$subject"},"object"]}},
[ {$set: {subject: {$concatArrays: [["$subject"], mmm]} }} ],
{multi:true});
How to get the sum of purchased deal's price (current year data) group by week, day, year using purchased_at field
My collection data:
{
"_id": ObjectId("5a66d619042e9f3a070d6864"),
"name": "Deal1",
"price": "2000",
"status": true,
"purchased_at": ISODate("2018-01-23T06:28:41.0Z")
}
{
"_id": ObjectId("5a66d619042e9f3a070d6872"),
"name": "Deal2",
"price": "500",
"status": true,
"purchased_at": ISODate("2018-01-13T06:28:41.0Z")
}
{
"_id": ObjectId("5a66d619042e9f3a070d6880"),
"name": "Deal3",
"price": "1000",
"status": true,
"purchased_at": ISODate("2018-02-13T06:28:41.0Z")
}
{
"_id": ObjectId("5a66d619042e9f3a070d6880"),
"name": "Deal4",
"price": "1000",
"status": false,
"purchased_at": ISODate("2018-01-11T06:28:41.0Z")
}
Can someone please help?
Since you're using non standard date format, you need to use filter():
$lastWeekSum = $collection->filter(function($i) {
Carbon::parse($i['purchased_at'])->gt(now()->subWeek());
})->sum('price');
If $i['purchased_at'] returns an object, you should convert it to a string like 2018-01-11T06:28:41.0Z before parsing it.
I'm in the process of developing Route Tracking/Optimization software for my refuse collection company and would like some feedback on my current data structure/situation.
Here is a simplified version of my MongoDB structure:
Database: data
Collections:
“customers” - data collection containing all customer data.
[
{
"cust_id": "1001",
"name": "Customer 1",
"address": "123 Fake St",
"city": "Boston"
},
{
"cust_id": "1002",
"name": "Customer 2",
"address": "123 Real St",
"city": "Boston"
},
{
"cust_id": "1003",
"name": "Customer 3",
"address": "12 Elm St",
"city": "Boston"
},
{
"cust_id": "1004",
"name": "Customer 4",
"address": "16 Union St",
"city": "Boston"
},
{
"cust_id": "1005",
"name": "Customer 5",
"address": "13 Massachusetts Ave",
"city": "Boston"
}, { ... }, { ... }, ...
]
“trucks” - data collection containing all truck data.
[
{
"truckid": "21",
"type": "Refuse",
"year": "2011",
"make": "Mack",
"model": "TerraPro Cabover",
"body": "Mcneilus Rear Loader XC",
"capacity": "25 cubic yards"
},
{
"truckid": "22",
"type": "Refuse",
"year": "2009",
"make": "Mack",
"model": "TerraPro Cabover",
"body": "Mcneilus Rear Loader XC",
"capacity": "25 cubic yards"
},
{
"truckid": "12",
"type": "Dump",
"year": "2006",
"make": "Chevrolet",
"model": "C3500 HD",
"body": "Rugby Hydraulic Dump",
"capacity": "15 cubic yards"
}
]
“drivers” - data collection containing all driver data.
[
{
"driverid": "1234",
"name": "John Doe"
},
{
"driverid": "4321",
"name": "Jack Smith"
},
{
"driverid": "3421",
"name": "Don Johnson"
}
]
“route-lists” - data collection containing all predetermined route lists.
[
{
"route_name": "monday_1",
"day": "monday",
"truck": "21",
"stops": [
{
"cust_id": "1001"
},
{
"cust_id": "1010"
},
{
"cust_id": "1002"
}
]
},
{
"route_name": "friday_1",
"day": "friday",
"truck": "12",
"stops": [
{
"cust_id": "1003"
},
{
"cust_id": "1004"
},
{
"cust_id": "1012"
}
]
}
]
"routes" - data collections containing data for all active and completed routes.
[
{
"routeid": "1",
"route_name": "monday1",
"start_time": "04:31 AM",
"status": "active",
"stops": [
{
"customerid": "1001",
"status": "complete",
"start_time": "04:45 AM",
"finish_time": "04:48 AM",
"elapsed_time": "3"
},
{
"customerid": "1010",
"status": "complete",
"start_time": "04:50 AM",
"finish_time": "04:52 AM",
"elapsed_time": "2"
},
{
"customerid": "1002",
"status": "incomplete",
"start_time": "",
"finish_time": "",
"elapsed_time": ""
},
{
"customerid": "1005",
"status": "incomplete",
"start_time": "",
"finish_time": "",
"elapsed_time": ""
}
]
}
]
Here is the process thus far:
Each day drivers begin by Starting a New Route. Before starting a new route drivers must first input data:
driverid
date
truck
Once all data is entered correctly the Start a New Route will begin:
Create new object in collection “routes”
Query collection “route-lists” for “day” + “truck” match and return "stops"
Insert “route-lists” data into “routes” collection
As driver proceeds with his daily stops/tasks the “routes” collection will update accordingly.
On completion of all tasks the driver will then have the ability to Complete the Route Process by simply changing “status” field to “active” from “complete” in the "routes" collection.
That about sums it up. Any feedback, opinions, comments, links, optimization tactics are greatly appreciated.
Thanks in advance for your time.
You database schema looks like for me as 'classic' relational database schema. Mongodb good fit for data denormaliztion. I guess when you display routes you loading all related customers, driver, truck.
If you want make your system really fast you may embedd everything in route collection.
So i suggest following modifications of your schema:
customers - as-is
trucks - as-is
drivers - as-is
route-list:
Embedd data about customers inside stops instead of reference. Also embedd truck. In this case schema will be:
{
"route_name": "monday_1",
"day": "monday",
"truck": {
_id = 1,
// here will be all truck data
},
"stops": [{
"customer": {
_id = 1,
//here will be all customer data
}
}, {
"customer": {
_id = 2,
//here will be all customer data
}
}]
}
routes:
When driver starting new route copy route from route-list and in addition embedd driver information:
{
//copy all route-list data (just make new id for the current route and leave reference to routes-list. In this case you will able to sync route with route-list.)
"_id": "1",
route_list_id: 1,
"start_time": "04:31 AM",
"status": "active",
driver: {
//embedd all driver data here
},
"stops": [{
"customer": {
//all customer data
},
"status": "complete",
"start_time": "04:45 AM",
"finish_time": "04:48 AM",
"elapsed_time": "3"
}]
}
I guess you asking yourself what do if driver, customer or other denormalized data changed in main collection. Yeah, you need update all denormalized data within other collections. You will probably need update billions of documents (depends on your system size) and it's okay. You can do it async if it will take much time.
What benfits in above data structure?
Each document contains all data that you may need to display in your application. So, for instance, you no need load related customers, driver, truck when you need display routes.
You can make any difficult queries to your database. For example in your schema you can build query that will return all routes thats contains stops in stop of customer with name = "Bill" (you need load customer by name first, get id, and look by customer id in your current schema).
Probably you asking yourself that your data can be unsynchronized in some cases, but to solve this you just need build a few unit test to ensure that you update your denormolized data correctly.
Hope above will help you to see the world from not relational side, from document database point of view.