I'm looking for the most effective way to extract the following information from D2L.
For a given user find all Department in which he is not enrolled, but is enrolled in any Offerings belonging to this Department.
The only solution I see is:
Call GET .../enrollments/users/{id}/orgUnits with type = Offering into List1
For each entry in List1 call GET .../courses/{courseId} to get course department information and build on-the-fly List2 of unique departments.
Call GET .../enrollments/users/{id}/orgUnits with type = Department into List3
Compare List2 vs List3
It's obvious that if user is teaching many Courses then too many calls will be required in step2.
Any suggestions are greatly appreciated.
For your step 2 which starts with the set of the student's enrolled course offerings, you may find it easier to call GET /d2l/api/lp/(version)/orgstructure/(orgUnitId)/ancestors/ to find all the departments containing those course offerings, and produce your List 2.
Unfortunately, the Valence Learning Framework doesn't really give you any set-predicate API calls around the org structure (to determine if a given orgUnit Y is a descendant of another orgUnit X, and so forth).
Related
Use case:
I need to create a report on office groups without owner. This happens when people leave the company and their account is deleted. Their groups live further, but eventually group expiration kicks in and somebody need to take action.
Question: What is the easiest was to create query in graph to filter groups that do not have an owner?
What I currently do is:
List all groups
Enumerate this list and look for groups where the owner array is empty:
https://graph.microsoft.com/v1.0/groups/{id}/owners?$select=mail
This returns an empty array when there are no owners.
{
"#odata.context": "https://graph.microsoft.com/v1.0/$metadata#directoryObjects(mail)",
"value": []
}
This, in theory, works, but takes ages as we have many 10 thousands of groups, so I am looking for a solution that makes this possible with one query. I also tried to filter the exprationDatTime property to limit results but query this doesn't seem to be supported. I mainly need groups that are due to expire.
There is no way how to get groups without owners with one query.
What you can do is to query all groups, expand owners and select only id of the group and id of the owner. It will minimize the response size.
Then iterate through the all groups and check for empty owners collection.
GET https://graph.microsoft.com/v1.0/groups?$expand=owners($select=id)&$select=id
I am in the process of designing this E-R diagram for a shop of which I have shown part of below (the rest is not relevant). See the link please:
E-R diagram
The issue that I have is that the shop only sells two items, Socks and Shoes.
Have I correctly detailed this in my diagram? I'm not sure if my cardinalities and/or my design is correct. A customer has to buy at least one of these items for the order to exist (but has the liberty to buy any number).
The Shoe and Sock entities would have their respective ID attribute, and I am planning to translate to a relational schema like this:
(I forgot to add to my diagram the ORDER_CONTAINS relationship to have an attribute called "Quantity". )
Table: Order_Contains
ORDER_ID | SHOEID | SOCKID | QTY
primary key | FK, could be null |FK, could be null | INT
This clearly won't work since the Qty would be meaningless. Is there a way I can reduce the products to just two products and make all this work?
Having two one-to-many relationships combined into one with nullable fields is a poor design. How would you record an order containing both shoes and socks - a row per shoe with SOCKID set to NULL and vice-versa for socks, or would you combine rows? In the former case the meaning of QTY is clear though it depends on the contents of SHOEID/SOCKID fields, but what would the QTY mean in the latter case? How would you deal with rows where both SHOEID and SOCKID are NULL and the QTY is positive? Keep in mind Murphy's law of databases - if it can be recorded it will be. Worse, your primary key (ORDER_ID) will prevent you from recording more than one row, so a customer couldn't buy more than one (pair of) socks or shoes.
A better design would be to have two separate relations:
Order_Socks (ORDER_ID PK/FK, SOCKID PK/FK, QTY)
Order_Shoes (ORDER_ID PK/FK, SHOEID PK/FK, QTY)
With this, there's only one way to record the contents of an order and it's unambiguous.
You have not explained very well the context here. I'll try to explain from what I understand, and give you some hints.
Do your shop only and always (forever) sell 2 products? Do the details of these products (color, model, weight, width, etc...) need to be persisted in the database? If yes, then we have two entities in the model, SOCKS and SHOES. Each entity has its own properties. A purchase or a order is usually seen as an event on the ERD. If your customers always buys (or order) socks with shoes, then there will always be a link between three entities:
CLIENTS --- SHOES --- SOCKS
This connection / association / relationship is an event, and this would be the purchase (or order).
If a customer can buy separate shoes and socks, then socks and shoes are subtypes of a super entity, called PRODUCTS, and a purchase is an event between CUSTOMERS and PRODUCTS. Here in this case we have a partitioning relationship.
If however, your customers buy separate products, and your store will not sell forever only 2 products, and details of the products are not always the same and will not be saved as columns in a table, then the case is another.
Shoes and socks are considered products, as well as other items that can be considered in future. Thus, we have records/rows in a PRODUCTS table.
When a customer places an order (or a purchase), he (she) is acquiring products. There is a strong link between customers and products here, again usually an event, which would be the purchase (or a order).
I do not know if you do it, but before thinking of start a diagram, type the problem context in a paper or a document. Show all details present in the situation.
The entities are seen when they have properties. If you need to save the name of a customer, the customer's eye color, the customer's e-mail, and so on, then you will have certainly a CUSTOMER entity.
If you see entities relate in some way, then you have a relationship, and you should ask yourself what kind of relationship these entities form. In your case of products and customers, we have a purchasing relationship there between. The established relationship is a purchase (or an order, you call it). One customer can buy various products, and one product (not on the same shelf, is the type, model) can be purchased for several customers, thus, we have a Many-To-Many relationship.
The relationship created changes according to the context. Whatever, we'll invent something crazy here as examples. Say we have customers and products. Say you want to persist a situation where customers lick Products (something really crazy, just for you to see how the context says the relationship).
There would be an intimate connection between customers and products entities (really close... I think...). In this case, the relationship represents a history of customers licking products. This would generate an EVENT. In this event you could put properties such as the date, the amount of times a customer licked a proper product, the weather, the time, the traffic light color on the street, etc., only what you need to persist according to your context, your needs.
Remember that for N-N relationships created, we need to see if new entities (out of relationship) will emerge. This usually happens when you are decomposing the conceptual model to the logical model. Probably, product orders will generate not one but two entities: The ORDER and the products of orders. It is within the products of orders that you place the list of products ordered from each customer, and the quantity.
I would like to present various materials to study ERD, but unfortunately they are all in Portuguese. I hope I have helped you in some way. If you want to be more specific about your problem, I think I can really help you best. Anything, please ask.
I'm trying to model contractor relationships in Neo4J and I'm struggling with how to conceptualize subcontracts. I have nodes for Government Agencies (label: Agency) and Contractors (label:Company). Each of these have geospatial Office nodes with the HAS_OFFICE relationship. I'm thinking of creating a node that represents a Government Contract (label: Contract).
Here's what I'm struggling with: A Contract has a Government Agency (I'm thinking this is a "HAS CONTRACT" relationship) and one or more prime contractor(s) (I'm thinking this is a "PRIME" relationship). Here's where it gets complicated. Each of those primes contractors can have subcontractors under the prime contract only. Graphically, this is:
(Agency) -[HAS_CONTRACT]-> (Contract) -[PRIME]-> (Company 1) -[SUB]-> (Company 2)
The problem I'm struggling with is that the [SUB] relationship is only for certain contracts -- not all. For example:
Agency 1 -HAS-> Contract ABC -P-> Company 1 -S-> Company 2
Agency 1 -HAS-> Contract ABC -P-> Company 3 -S-> Company 4
Agency 2 -HAS-> Contract XYZ -P-> Company 1
Agency 2 -HAS-> Contract XYZ -P-> Company 4 -S-> Company 2
I want some way to search on that so I can ask cypher questions like "Find ways Agency 2 can put money on contract with Company 2." It should come back with the XYZ contract through Company 4, and NOT the XYZ contract through Company 1.
It seems like maybe storing and filtering on data within the relationship would work, but I'm struggling with how. Can I say Prima and Sub relationships have a property, "contract_id" that must match Contract['id']? If so, how?
Edit: I don't want to have to specify the contract name for the query. Based on #MarkM's reply, I'm thinking something like:
MATCH (a:Agency)-[:HAS]-(c:Contract)-[:PRIME {contract_id:c.id}]
-(p:Company)-[:SUB {contract_id:c.id}]-(s:Company)
RETURN s
I'd also like to be able to use things like shortestPath to find the shortest path between an agency and a contractor that follows a single contract ID.
I'd create the subcontractor by having two relationships, one to the contractor and one to the contract.
(:Agency)-[:ISSUES]->(con:Contract)-[:PRIMARY]->(contractor:Company)
(con:Contract)-[:SECONDARY]->(subContractor:Company)<-[:SUBCONTRACTS]-(contractor:Company)
Perhaps you can mode your use-case as a graph-gist, which is a good way of documenting and discussing modeling issues.
This seems pretty simple; I apologize if I've misunderstood the question.
If you want subcontractors you can simply query:
MATCH (a:Agency)-[:HAS]-(:Contract)-[:PRIME]-(p:Company)-[:SUB]-(s:Company) RETURN s
This will return all companies that are subcontractors. The query matches the whole pattern. So if you want XYZ contract subcontractors you simply give it the parameter:
MATCH (a:Agency)-[:HAS]-(:Contract {contractID: XYZ})-[:PRIME]-(p:Company)-[:SUB]-(s:Company) RETURN s
You'll only get company 2.
EDIT: based on your edit:
"Find ways Agency 2 can put money on contract with Company 2"
This seems to require some domain-specific knowledge which I don't have. I assume Agency 2 can only put money on subcontractors but not primes?? I might help if you reword so we know exactly what your trying to get from the graph. From my reading it looks like you want all companies that are subcontractors under Company 2's contracts. Is that right?
If that's what you want, again you just give Neo the path:
MATCH (a:Agency: {AgencyID: 2)-[:HAS]
-(c:Contract)-[:PRIME]-(:Company)-[:SUB]-(s:Company: {companyID: 2)
RETURN c, s
This will give you a list of all contracts under XYZ for which Company 2 is a subcontractor. With the current example, it will one row: [c:Contract XYZ, s:Company 2]. If Agency 2 had more contracts under which Company 2 subcontracted, you would get more rows.
You can't do this: [:PRIME {contract_id:c.id}] [:SUB {contract_id:c.id}] because Prime and Sub relationships shouldn't have contract_id properties. They don't need them — the very fact that they are connected to a contract is enough.
One thing that might make this a little more complicated is if the subcontractors also have subcontractors, but that's not evident.
Okay take 2:
So the problem isn't captured well in the original example data — sorry for missing it. A better example is:
Agency 1 -HAS-> Contract ABC -P-> Company 1 -S-> Company 2
Agency 1 -HAS-> Contract XYZ -P-> Company 1 -S-> Company 3
Now if I ask
MATCH (a:Agency)-[:HAS_CONTRACT]-(ABC:Contract {id:ABC})-[:PRIME]
-(c:Company)-[:SUBS]-(c2) RETURN c2
I'll get both Company 2 and 3 even though only 2 is on ABC, Right?
The problem here is the data model not the query. There's no way to distinguish a company's subs because they are all connected directly to the company node. You could put a property on the sub relationship with the prime ID, but a better way that really captures the information is to add another contract node under company. Whether you label this as a different type depends on your situation.
Company1 then [:HAS] a contract which the subs are connected to. The contract can then point back to the prime contract with a relationship of something like [:PARENT] or [:PRIME] or maybe from the prime to the sub with a [:SUBCONTRACT] relationship
Now everything becomes much easier. You can find all subcontracts under a particular contract, all subcontracts a particular company [:HAS], etc. To find all subcontractors under a particular contract you could query something like this:
MATCH (contract:Contract { id:"ContractABC" })-[:PRIME]-(c:Company)
-[:HAS]->(subcontract:Contract)-[:PARENT]-(contract)
WITH c, subcontract
MATCH (subcontract)-[:SUBS]-(subcontractor:Company)
RETURN c, subcontractor
This should give you a list of all companies and their subcontractors under contract ABC. In this case Company 1, Company 2 (but not company 3).
Here's a console example: http://console.neo4j.org/?id=flhv8e
I've left the original [:SUB] relationships but you might not need them.
I am building an inventory tracking tool to help people track either unique items (one-offs - say a vintage T-Shirt) or groups of items (a T-shirt design where I have a quantity). The data structures will be very similar, so that:
**Item**
Title
Status (sold, for sale) <- right now this is a simple array
Location <- this is a relationship to a diff model
etc...
**Item Group**
Title
Quantity
Status ([quantity] sold, [quantity] for sale) <- this should be an hstore??
Locations ([quantity] location1, [quantity] location2) <- not sure about this yet!
etc...
I'm expecting to use different forms to gather this information, as too much complexity on the form to accommodate these differences will add difficulty for my user group.
So my questions are as follows:
What is the best data solution for this? Do I want to have two models/controllers or try to extend the Item model? How do people usually handle this sort of issue?
I do have the requirement that I need to show the user all of their inventory (items and groups) at once, but this seems the smaller task to me.
Reduce your headaches and don't differentiate between unique items and non-unique ( ie, all items have a quantity ).
Then you want a "purchace" model, and then a "item_purchace" model to act as a join table.
Following the layout here: guides.rubyonrails.org...
I'm trying out recommendation system(academic exercise) for a specific use case where users and items are one to many associated. Say at a given time a particular item can be owned by only one user. User can own multiple items at a time. Any particular item has many similar items which might interest the owning user. I want to find an item and recommend it to user. Usually in user based recommendation, entities will be of many to many association. If user U1 owns items I1,I2,I3 and user U2 owns items I1,I2,I3,I4 we would recommend I4 to U1. In my case one item can be owned by only one user at a given time. How to perform recommendation in this case. Is it possible to perform user based recommendation?
One possible option is always to conert one problem to another. Given one-to-many information, you can for each item X (knowing some kind of similarity measure, which is required here, without it you cannot do any recomendation) you create an object "items similar to X to some extent" call it C[X], and once you go through all items -- you get new kind of data. You have users, and "items clusters" C. Now you can assume that user A "likes" cluster C[X] iff user A likes any item from C[X]. This way you have many-to-many relation on the same data, with a bit of "smoothing". Now you can use any kind of existing system, and once you get the recommendation C[Y] you "recommend" any free (avaliable) item from C[Y].