Given a JSON document on couchbase, for example, a milestone collections, which is similar to this:
{
"milestoneDate" : /Date(1335191824495+0100)/,
"companyId" : 43,
"ownerUserId": 475,
"participants" : [
{
"userId": 2,
"docId" : "132546"
},
{
"userId": 67,
"docId" : "153"
}
]
}
If I were to select all the milestones of the company 43 and want to order them by latest first.. my view on couchbase would be something similar to this:
function (doc, meta) {
if(doc.companyId && doc.milestoneDate)
{
//key made up of date particles + company id
var eventKey = dateToArray(new Date(parseInt(doc.milestoneDate.substr(6))));
eventKey.push(doc.companyId);
emit(eventKey, null);
}
}
I do get both dates and the company Id on rest urls.. however, being quite new to couchbase, I am unable to work out how to restrict the view to return only milestones of company 43
The return key is similar to this:
"key":[2013,6,19,16,11,25,14]
where the last element (14) is the company id.. which is quite obviously wrong.
The query parameters that I have tried are:
&descending=true&startkey=[{},43]
&descending=true&startkey=[{},43]&endKey=[{},43]
tried adding companyId to value but couldn't restrict return results by value.
And according to couchbase documentation I need the date parts in the beginning to sort them. How do I restrict them by company id now, please?
thanks.
Put the company id at the start of the array, and because you'll be limiting by company id, couchbase sorts by company id and then by date array so you will be only ever getting the one company's milestone documents
I'd modify the view to emit
emit([doc.copmanyId, eventKey], null);
and then you can query the view with
&descending=true&startkey=[43,{}]
This was what worked for me previously..
I went back and tried it with end key and this seems to work - restricts and orders as required:
&descending=true&startkey=[43,{}]&endkey=[42,{}]
or
&descending=true&startkey=[43,{}]&endkey=[43,{}]&inclusive_end=true
either specify the next incremented/decremented value (based on descending flag) with end key, or use the same endkey as startkey and set inclusiveEnd to true
Both of these options should work fine. (I only tested the one with endkey=42 but they should both work)
Related
I have a situation : Category - Master data with different types.
Order - Has a reference to Category.
It is a one-to-one mapping from Order to Category. Order table has a foreign key column to Category.
Now api to get Orders
/users/orders
Will the return type as
{ "name: "abc", "categoryId" : 23 }
will be fine or should we return the json as
{ "name: "abc", "category" : "CAT-A" }
We also have a create/update Order use case with client knowing the category.
We need a api to post new Order with a Category.
Should it be something like this?
1. post /api/orders { "categoryId" : 23, ....}
Or something like this?
2. post /api/orders/category/23/order
first, use identifiers (or links!):
{ "name: "abc", "categoryId" : 23 }
or
{ "name: "abc", "category" : "/api/categories/23" }
not names (because those could change from time to time)
{ "name: "abc", "category" : "CAT-A" }
For the posting of orders I would suggest to use
post /api/orders { "categoryId" : 23, ....}
just because you are adding an order on the order resource. The order should already have a category referenced (or linked!).
This approach
post /api/orders/category/23/order
would also be okay. But the client would need to build an url with information that is already contained in the request body, so things only got a little more complicated (what if the categories in url and request body are not the same? What if the category in the request body is missing? Is the request still valid in this case?)
I am new to couchbase and I have been going through couchbase documents and other online resources for a while but I could't get my query working. Below is the data structure and my query:
Table1:
{
"jobId" : "101",
"jobName" : "abcd",
"jobGroup" : "groupa",
"created" : " "2018-05-06T19:13:43.318Z",
"region" : "dev"
},
{
"jobId" : "102",
"jobName" : "abcd2",
"jobGroup" : "groupa",
"created" : " "2018-05-06T22:13:43.318Z",
"region" : "dev"
},
{
"jobId" : "103",
"jobName" : "abcd3",
"jobGroup" : "groupb",
"created" : " "2018-05-05T19:11:43.318Z",
"region" : "test"
}
I need to get the jobId which has the latest job information (max on created timestamp) for a given jobGroup and region (group by jobGroup and region).
My sql query doesn't help me using self-join on jobId.
Query:
/*
Idea is to pull out the job which was executed latest for all possible groups and region and print the details of that particular job
select * from (select max(DATE_FORMAT_STR(j.created,'1111-11-11T00:00:00+00:00')) as latest, j.jobGroup, j.region from table1 j
group by jobGroup, region) as viewtable
join table t
on keys meta(t).id
where viewtable.latest in t.created and t.jobGroup = viewtable.jobGroup and
viewtable.region = t.region
Error Result: No result displayed
Desired result :
{
"jobId" : "102",
"jobName":"abcd2",
"jobGroup":"groupa",
"latest" :"2018-05-06T22:13:43.318Z",
"region":"dev"
},
{
"jobId" : "103",
"jobName" : "abcd3",
"jobGroup" : "groupb",
"created" : " "2018-05-05T19:11:43.318Z",
"region" : "test"
}
If I understand your query correctly, this can be answered using 'group by' and no join. I tried entering your sample data and the following query gives the correct result:
select max([created,d])[1] max_for_group_region
from default d
group by jobGroup, region;
How does it work? It uses 'group by' to group documents by jobGroup and region, then creates a two-element array holding, for every document in the group:
the 'created' timestamp field
the document where the timestamp came from
It then applies the max function on the set of 2-element arrays. The max of a set of arrays looks for the maximum value in the first array position, and if there's a tie look at the second position, and so on. In this case we are getting the two-element array with the max timestamp.
Now we have an array [ timestamp, document ], so we apply [1] to extract just the document.
I'm seeing some inconsistencies and invalid JSON in your examples, so I'm going to do the best I can. First off, I'm using Couchbase Server 5.5 which provides the new ANSI JOIN syntax. There might be a way to do this in an earlier version of Couchbase Server.
Next, I created an index on the created field: CREATE INDEX ix_created ON bucketname(created).
Then, I use a subquery to get the latest date, aggregated by jobGroup and region. I then join the latest date from this query to the entire bucket and select the fields that (I think) you want in your desired result:
SELECT k.jobId, k.jobName, k.jobGroup, k.created AS latest, k.region
FROM (
SELECT j.jobGroup, j.region, MAX(j.created) as latestDate
FROM so j
GROUP BY j.jobGroup, j.region
) dt
LEFT JOIN so k ON k.created = dt.latestDate;
Problems with this approach:
If two documents have the exact same date, this isn't a reliable way to determine the latest. You can add a LIMIT 1 to the subquery, which would just pick one arbitrarily, or you could ORDER BY whatever your preference is.
Subquery performance: I don't know how large your data set is, but this could be pretty slow.
Requires Couchbase Server 5.5, which is currently in beta.
If you are using a different version of Couchbase Server, you may want to consider asking in the Couchbase N1QL Forums for a more expert answer.
Assuming I have the following MySQL tables to represent pricebooks, items and the relationship between them:
item - item_id|name|...etc
pricebook - pricebook_id|name|...etc
and the following pivot table
pricebook_item - pricebook_id|item_id|price|...etc
I have the correlating Eloquent models: Pricebook, Item and a repository named PricebookData to retrieve the necessary information.
Within the PricebookData repository, I need to get the pricebook data grouped by pricebook id and then keyed by item_id for easy access on client side.
If I do:
Pricebook::all()->groupBy('pricebook_id');
I get the information grouped by the pricebook_id but inside each pricebook the keys are simple numeric index (it arrives as js array) and not the actual product_id. So when returning to client side Javascript, the result arrives as the following:
pricebookData: {1: [{}, {}, {}...], 2: [{}, {}, {}...]}
The problem with the prices arriving as array, is that I can not access it easily without iterating the array. Ideally I would be able to receive it as:
pricebookData: {1: {1001:{}, 1002: {}, 1003: {}}, 2: {1001:{}, 1002: {}, 1003: {}}}
//where 1001, 1002, 1003 are actual item ids
//with this result format, I could simply do var price = pricebookData[1][1001]
I've also tried the following but without success:
Pricebook::all()->keyBy('item_id')->groupBy('pricebook_id');
The equivalent of what I am trying to avoid is:
$prices = Pricebook::all();
$priceData = [];
foreach ($prices as $price)
{
if (!isset($priceData[$price->pricebook_id]))
{
$priceData[$price->pricebook_id] = [];
}
$priceData[$price->pricebook_id][$price->item_id] = $price;
}
return $priceData;
I am trying to find a pure elegant Eloquent/Query Builder solution.
I think what you want is
Pricebook::all()
->groupBy('pricebook_id')
->map(function ($pb) { return $pb->keyBy('item_id'); });
You first group by Pricebook, then each Pricebook subset is keyed by item_id. You were on the right track with
Pricebook::all()->keyBy('item_id')->groupBy('pricebook_id');
unfortunately, as it is implemented, the groupBy resets previous keys.
Update:
Pricebook::all()->keyBy('item_id')->groupBy('pricebook_id', true);
(groupBy second parameter $preserveKeys)
I'm fairly new to couchbase and have tried to find the answer to a particular query I'm trying to create with not much success so far.
I've debated between using a view or N1QL for this particular case and settled with N1QL but haven't managed to get it to work so maybe a view is better after all.
Basically I have the document key (Group_1) for the following document:
Group_1
{
"cbType": "group",
"ID": 1,
"Name": "Group Atlas 3",
"StoreList": [
2,
4,
6
]
}
I also have 'store' documents, their keys are listed in this document's storelist. (Store_2, Store_4, Store_6 and they have a storeID value that is 2, 4 and 6) I basically want to obtain all 3 documents listed.
What I do have that works is I obtain this document with its id by doing:
var result = CouchbaseManager.Bucket.Get<dynamic>(couchbaseKey);
mygroup = JsonConvert.DeserializeObject<Group> (result.ToString());
I can then loop through it's storelist and obtain all it's stores in the same manner, but i don't need anything else from the group, all i want are the stores and would have prefered to do this in a single operation.
Does anyone know how to do a N1QL directly unto a specified document value?
Something like (and this is total imaginary non working code I'm just trying to clearly illustrate what I'm trying to get at):
SELECT * FROM mycouchbase WHERE documentkey IN
Group_1.StoreList
Thanks
UPDATE:
So Nic's solution does not work;
This is the closest I get to what I need atm:
SELECT b from DataBoard c USE KEYS ["Group_X"] UNNEST c.StoreList b;
"results":[{"b":2},{"b":4},{"b":6}]
Which returns the list of IDs of the Stores I want for any given group (Group_X) - I haven't found a way to get the full Stores instead of just the ID in the same statement yet.
Once I have, I'll post the full solution as well as all the speed bumps I've encountered in the process.
I apologize if I have a misunderstanding of your question, but I'm going to give it my best shot. If I misunderstood, please let me know and we'll work from there.
Let's use the following scenario:
group_1
{
"cbType": "group",
"ID": 1,
"Name": "Group Atlas 3",
"StoreList": [
2,
4,
6
]
}
store_2
{
"cbType": "store",
"ID": 2,
"name": "some store name"
}
store_4
{
"cbType": "store",
"ID": 4,
"name": "another store name"
}
store_6
{
"cbType": "store",
"ID": 6,
"name": "last store name"
}
Now lets say you wan't to query the stores from a particular group (group_1), but include no other information about the group. You essentially want to use N1QL's UNNEST and JOIN operators.
This might leave you with a query like so:
SELECT
stores.name
FROM `bucket-name-here` AS groups
UNNEST groups.StoreList AS groupstore
JOIN `bucket-name-here` AS stores ON KEYS ("store_" || groupstore.ID)
WHERE
META(groups).id = 'group_1';
A few assumptions are made in this. Both your documents exist in the same bucket and you only want to select from group_1. Of course you could use a LIKE and switch the group id to a percent wildcard.
Let me know if something doesn't make sense.
Best,
Try this query:
select Name
from buketname a join bucketname b ON KEYS a.StoreList
where Name="Group Atlas 3"
Based on your update, you can do the following:
SELECT b, s
FROM DataBoard c USE KEYS ["Group_X"]
UNNEST c.StoreList b
JOIN store_bucket s ON KEYS "Store_" || TO_STRING(b);
I have a similar requirement and I got what I needed with a query like this:
SELECT store
FROM `bucket-name-here` group
JOIN `bucket-name-here` store ON KEYS group.StoreList
WHERE group.cbType = 'group'
AND group.ID = 1
I am trying to learn mongodb. Suppose there are two tables and they are related. For example like this -
1st table has
First name- Fred, last name- Zhang, age- 20, id- s1234
2nd table has
id- s1234, course- COSC2406, semester- 1
id- s1234, course- COSC1127, semester- 1
id- s1234, course- COSC2110, semester- 1
how to insert data in the mongo db? I wrote it like this, not sure is it correct or not -
db.users.insert({
given_name: 'Fred',
family_name: 'Zhang',
Age: 20,
student_number: 's1234',
Course: ['COSC2406', 'COSC1127', 'COSC2110'],
Semester: 1
});
Thank you in advance
This would be a assuming that what you want to model has the "student_number" and the "Semester" as what is basically a unique identifier for the entries. But there would be a way to do this without accumulating the array contents in code.
You can make use of the upsert functionality in the .update() method, with the help of of few other operators in the statement.
I am going to assume you are going this inside a loop of sorts, so everything on the right side values is actually a variable:
db.users.update(
{
"student_number": student_number,
"Semester": semester
},
{
"$setOnInsert": {
"given_name": given_name,
"family_name": family_name,
"Age": age
},
"$addToSet": { "courses": course }
},
{ "upsert": true }
)
What this does in an "upsert" operation is first looks for a document that may exist in your collection that matches the query criteria given. In this case a "student_number" with the current "Semester" value.
When that match is found, the document is merely "updated". So what is being done here is using the $addToSet operator in order to "update" only unique values into the "courses" array element. This would seem to make sense to have unique courses but if that is not your case then of course you can simply use the $push operator instead. So that is the operation you want to happen every time, whether the document was "matched" or not.
In the case where no "matching" document is found, a new document will then be inserted into the collection. This is where the $setOnInsert operator comes in.
So the point of that section is that it will only be called when a new document is created as there is no need to update those fields with the same information every time. In addition to this, the fields you specified in the query criteria have explicit values, so the behavior of the "upsert" is to automatically create those fields with those values in the newly created document.
After a new document is created, then the next "upsert" statement that uses the same criteria will of course only "update" the now existing document, and as such only your new course information would be added.
Overall working like this allows you to "pre-join" the two tables from your source with an appropriate query. Then you are just looping the results without needing to write code for trying to group the correct entries together and simply letting MongoDB do the accumulation work for you.
Of course you can always just write the code to do this yourself and it would result in fewer "trips" to the database in order to insert your already accumulated records if that would suit your needs.
As a final note, though it does require some additional complexity, you can get better performance out of the operation as shown by using the newly introduced "batch updates" functionality.For this your MongoDB server version will need to be 2.6 or higher. But that is one way of still reducing the logic while maintaining fewer actual "over the wire" writes to the database.
You can either have two separate collections - one with student details and other with courses and link them with "id".
Else you can have a single document with courses as inner document in form of array as below:
{
"FirstName": "Fred",
"LastName": "Zhang",
"age": 20,
"id": "s1234",
"Courses": [
{
"courseId": "COSC2406",
"semester": 1
},
{
"courseId": "COSC1127",
"semester": 1
},
{
"courseId": "COSC2110",
"semester": 1
},
{
"courseId": "COSC2110",
"semester": 2
}
]
}