Hey guys i have the following array:
Array [
Object {
"data": "Cat Man",
"id": "1",
},
Object {
"data": "Bat Girl",
"id": "2",
},
Object {
"data": "Mr Penguin",
"id": "3",
},
Object {
"data": "Cheeky Cheetah",
"id": "4",
},
]
I am going to take the users input in the form of a search bar, how can i sort the array based off the users input.
So lets say the user inputs
Bat g
the array would be sorted to:
Array [
Object {
"data": "Bat Girl",
"id": "2",
},
Object {
"data": "Cat Man",
"id": "1",
},
Object {
"data": "Mr Penguin",
"id": "3",
},
Object {
"data": "Cheeky Cheetah",
"id": "4",
},
]
How can I achieve this?
I have been searching around the array sort function:
Array.prototype.sort()
However I have only seen how to sort based off number comparisons I have never seen an array sorted based off string values like a search. Please could someone help me with this!
Here is function to search data using string text.
const searchItem = txt => {
let text = txt.toLowerCase();
let tracks = dataArray;
let filterTracks = tracks.filter(item => {
if (item.data.toLowerCase().match(text)) {
return item;
}
});
console.log('filterTracks', filterTracks);
};
Array Should be like this
var dataArray = [
{
data: 'Cat Man',
id: '1',
},
{
data: 'Bat Girl',
id: '2',
},
{
data: 'Mr Penguin',
id: '3',
},
{
data: 'Cheeky Cheetah',
id: '4',
},
];
my data :
const DATA = [
{
id: "1",
from: "Canada",
name: "person1",
},
{
id: "2",
from: "Canada",
name: "person2",
},
{
id: "3",
from: "France",
name: "person3",
}];
i need to filter this flatList and only display people from Canada
I think you are looking for something like:
const result = DATA.filter(element=> element.from === "Canada")
Then you can use your result to display it in the format that you want.
I have the following structure:
{
id: "1",
invoices: [{ id: "1", balance: 1},{ id: "2", balance: 1}]
},
{
id: "2",
invoices: [{ id: "3", balance: 1},{ id: "4", balance: 1}]
}
I'm getting a list of invoices IDs that i shouldn't update, the rest i need to update the balance to 0.
I'm pretty new to MongoDB and managing to find a way to do it.
Let say you want to update all invoices of id 1 except invoice.id 2 try this one:
db.collection.update(
{ id: "1", "invoices.id": {$ne: 2} },
{
$set: {
"invoices.$[]": { balance: 0 }
}
}
)
First of all, you forgot the quotes around the field names. Your documents should be like this:
{
"id": "1",
"invoices": [{
"id": "1",
"balance": 1
}, {
"id": "2",
"balance": 1
}]
}
I have limited experience with MongoDB, as I learnt it this semester at University. However, here is my solution:
db.collection.update(
{ id: "1" },
{
$set: {
"invoices.0": { id: "1", balance: 0 }
}
}
)
What does this solution do?
It takes the document with id 1. That is your first document.
The $set operator replaces the value of a field with the specified value. (straight out from the MongoDB manual - MongoDB Manual - $set operator).
"invoices.0" takes the first invoice from the invoices array and then it updates the balance to 100.
Replace the word collection from db.collection with your collection name.
Try and see if it works. If not, I'd like someone with more experience to correct me.
LE: Now it works, try and see.
In my sample document, I have a campaign document that contains the _id of the document and an importData array. importData is an array of objects containing a unique date and source value.
My goal is to have an object updated with a unique date/source pair. I would like to have the new object replace any matching object. In the example below, Fred may have originally donated a TV, but I want my application to update the object to reflect he donated both a TV and a radio.
// Events (sample document)
{
"_id" : "Junky Joe's Jubilee",
"importData" : [
{
"date": "2015-05-31",
"source": "Fred",
"items": [
{item: "TV", value: 20.00},
{item: "radio", value: 5.34}
]
},
{
"date": "2015-05-31",
"source": "Mary",
"items": [
{item: "Dresser", value: 225.00}
]
}
]
}
My original thought was to do something like the code below, but not only am I updating importData with Fred's donations, I'm also blowing away anything else in the importData array:
var collection = db.collection("events");
collection.update(
{_id: "Junky Joe's Jubilee",
importData: {
date: "2015-05-31",
source: 'Fred'
},
}, // See if we can find a campaign object with this name
{
$set:
{"importData":
{
date: "2015-05-31",
source: 'Fred',
items: [
{item: "TV", value: 20.00},
{item: "radio", value: 5.34}
]
}
}
},
{upsert: true}); // Create a document if one does not exist for this campaign
When I tried pushing (instead of $set), I was getting multiple entries for the date/source combos (e.g. Fred would appear to have donated two items multiple times on "2015-05-31").
How would I go about doing that with the MongoDB native driver and NodeJS?
Try this
var collection = db.collection("events");
collection.update(
{_id: "Junky Joe's Jubilee",
importData: {
date: "2015-05-31",
source: 'Fred'
},
}, // See if we can find a campaign object with this name
{
$set:
{"importData.$":
{
date: "2015-05-31",
source: 'Fred',
items: [
{item: "TV", value: 20.00},
{item: "radio", value: 5.34}
]
}
}
},
{upsert: true}); // Create a document if one does not exist for this campaign
According to the documentation under Array update operators this should only modify the first element in the array, which matches the query.
I am querying for finding exact array match and retrieved it successfully but when I try to find out the exact array with values in different order then it get fails.
Example
db.coll.insert({"user":"harsh","hobbies":["1","2","3"]})
db.coll.insert({"user":"kaushik","hobbies":["1","2"]})
db.coll.find({"hobbies":["1","2"]})
2nd Document Retrieved Successfully
db.coll.find({"hobbies":["2","1"]})
Showing Nothing
Please help
The currently accepted answer does NOT ensure an exact match on your array, just that the size is identical and that the array shares at least one item with the query array.
For example, the query
db.coll.find({ "hobbies": { "$size" : 2, "$in": [ "2", "1", "5", "hamburger" ] } });
would still return the user kaushik in that case.
What you need to do for an exact match is to combine $size with $all, like so:
db.coll.find({ "hobbies": { "$size" : 2, "$all": [ "2", "1" ] } });
But be aware that this can be a very expensive operation, depending on your amount and structure of data.
Since MongoDB keeps the order of inserted arrays stable, you might fare better with ensuring arrays to be in a sorted order when inserting to the DB, so that you may rely on a static order when querying.
To match the array field exactly Mongo provides $eq operator which can be operated over an array also like a value.
db.collection.find({ "hobbies": {$eq: [ "singing", "Music" ] }});
Also $eq checks the order in which you specify the elements.
If you use below query:
db.coll.find({ "hobbies": { "$size" : 2, "$all": [ "2", "1" ] } });
Then the exact match will not be returned. Suppose you query:
db.coll.find({ "hobbies": { "$size" : 2, "$all": [ "2", "2" ] } });
This query will return all documents having an element 2 and has size 2 (e.g. it will also return the document having hobies :[2,1]).
Mongodb filter by exactly array elements without regard to order or specified order.
Source: https://savecode.net/code/javascript/mongodb+filter+by+exactly+array+elements+without+regard+to+order+or+specified+order
// Insert data
db.inventory.insertMany([
{ item: "journal", qty: 25, tags: ["blank", "red"], dim_cm: [ 14, 21 ] },
{ item: "notebook", qty: 50, tags: ["red", "blank"], dim_cm: [ 14, 21 ] },
{ item: "paper", qty: 100, tags: ["red", "blank", "plain"], dim_cm: [ 14, 21 ] },
{ item: "planner", qty: 75, tags: ["blank", "red"], dim_cm: [ 22.85, 30 ] },
{ item: "postcard", qty: 45, tags: ["blue"], dim_cm: [ 10, 15.25 ] }
]);
// Query 1: filter by exactly array elements without regard to order
db.inventory.find({ "tags": { "$size" : 2, "$all": [ "red", "blank" ] } });
// result:
[
{
_id: ObjectId("6179333c97a0f2eeb98a6e02"),
item: 'journal',
qty: 25,
tags: [ 'blank', 'red' ],
dim_cm: [ 14, 21 ]
},
{
_id: ObjectId("6179333c97a0f2eeb98a6e03"),
item: 'notebook',
qty: 50,
tags: [ 'red', 'blank' ],
dim_cm: [ 14, 21 ]
},
{
_id: ObjectId("6179333c97a0f2eeb98a6e05"),
item: 'planner',
qty: 75,
tags: [ 'blank', 'red' ],
dim_cm: [ 22.85, 30 ]
}
]
// Query 2: filter by exactly array elements in the specified order
db.inventory.find( { tags: ["blank", "red"] } )
// result:
[
{
_id: ObjectId("6179333c97a0f2eeb98a6e02"),
item: 'journal',
qty: 25,
tags: [ 'blank', 'red' ],
dim_cm: [ 14, 21 ]
},
{
_id: ObjectId("6179333c97a0f2eeb98a6e05"),
item: 'planner',
qty: 75,
tags: [ 'blank', 'red' ],
dim_cm: [ 22.85, 30 ]
}
]
// Query 3: filter by an array that contains both the elements without regard to order or other elements in the array
db.inventory.find( { tags: { $all: ["red", "blank"] } } )
// result:
[
{
_id: ObjectId("6179333c97a0f2eeb98a6e02"),
item: 'journal',
qty: 25,
tags: [ 'blank', 'red' ],
dim_cm: [ 14, 21 ]
},
{
_id: ObjectId("6179333c97a0f2eeb98a6e03"),
item: 'notebook',
qty: 50,
tags: [ 'red', 'blank' ],
dim_cm: [ 14, 21 ]
},
{
_id: ObjectId("6179333c97a0f2eeb98a6e05"),
item: 'planner',
qty: 75,
tags: [ 'blank', 'red' ],
dim_cm: [ 22.85, 30 ]
}
]
This query will find exact array with any order.
let query = {$or: [
{hobbies:{$eq:["1","2"]}},
{hobbies:{$eq:["2","1"]}}
]};
db.coll.find(query)
with $all we can achieve this.
Query : {cast:{$all:["James J. Corbett","George Bickel"]}}
Output : cast : ["George Bickel","Emma Carus","George M. Cohan","James J. Corbett"]
Using aggregate this is how I got mine proficient and faster:
db.collection.aggregate([
{$unwind: "$array"},
{
$match: {
"array.field" : "value"
}
},
You can then unwind it again for making it flat array and then do grouping on it.
This question is rather old, but I was pinged because another answer shows that the accepted answer isn't sufficient for arrays containing duplicate values, so let's fix that.
Since we have a fundamental underlying limitation with what queries are capable of doing, we need to avoid these hacky, error-prone array intersections. The best way to check if two arrays contain an identical set of values without performing an explicit count of each value is to sort both of the arrays we want to compare and then compare the sorted versions of those arrays. Since MongoDB does not support an array sort to the best of my knowledge, we will need to rely on aggregation to emulate the behavior we want:
// Note: make sure the target_hobbies array is sorted!
var target_hobbies = [1, 2];
db.coll.aggregate([
{ // Limits the initial pipeline size to only possible candidates.
$match: {
hobbies: {
$size: target_hobbies.length,
$all: target_hobbies
}
}
},
{ // Split the hobbies array into individual array elements.
$unwind: "$hobbies"
},
{ // Sort the elements into ascending order (do 'hobbies: -1' for descending).
$sort: {
_id: 1,
hobbies: 1
}
},
{ // Insert all of the elements back into their respective arrays.
$group: {
_id: "$_id",
__MY_ROOT: { $first: "$$ROOT" }, // Aids in preserving the other fields.
hobbies: {
$push: "$hobbies"
}
}
},
{ // Replaces the root document in the pipeline with the original stored in __MY_ROOT, with the sorted hobbies array applied on top of it.
// Not strictly necessary, but helpful to have available if desired and much easier than a bunch of 'fieldName: {$first: "$fieldName"}' entries in our $group operation.
$replaceRoot: {
newRoot: {
$mergeObjects: [
"$__MY_ROOT",
{
hobbies: "$hobbies"
}
]
}
}
}
{ // Now that the pipeline contains documents with hobbies arrays in ascending sort order, we can simply perform an exact match using the sorted target_hobbies.
$match: {
hobbies: target_hobbies
}
}
]);
I cannot speak for the performance of this query, and it may very well cause the pipeline to become too large if there are too many initial candidate documents. If you're working with large data sets, then once again, do as the currently accepted answer states and insert array elements in sorted order. By doing so you can perform static array matches, which will be far more efficient since they can be properly indexed and will not be limited by the pipeline size limitation of the aggregation framework. But for a stopgap, this should ensure a greater level of accuracy.