If I have two entities in my model, "People" and "Addresses", and a particular Person has zero or more addresses, accessed via an AddressList navigation property, can I write an OData query that answers the following question:
"Which people have a last name ending in Smith and at least one address?"
It seems to me I can only do one predicate here, e.g.
http://localhost:55100/DemographicsDataService.svc/People?$filter=endswith(LastName,'Smith')
(I'm not yet convinced I can even write a $filter to handle the second predicate.. in which case, assume I'm trying to answer the question, "Last name ending in smith and first name starting with Mary")
You can definitely combine predicates in the $filter. For example:
/People?$filter=endswith(LastName,'Smith') and startswith(FirstName,'Mary')
For details around supported operators and such please see this page: http://www.odata.org/documentation/odata-version-2-0/uri-conventions#FilterSystemQueryOption
Currently OData doesn't have a way to express the question "People which have at least one address".
Depending on your data it might be feasible to download all People fulfilling the first criteria and determine those with address on the client instead.
Related
On this REST tutorial site,
When, if ever, is it appropriate to put something like
http://dev.m.gatech.edu/developer/USER_NAME/api/WIDGET_NAME/test?query=someparam
instead of
http://dev.m.gatech.edu/developer/USER_NAME/api/WIDGET_NAME/test/someparam
or
http://dev.m.gatech.edu/developer/USER_NAME/api/WIDGET_NAME/test/someparam/var1/param/var2/param
?
I've seen various things on SO.
All cases where you are performing a GET request and need to pass some parameters should be in the form of ?param=value.
So is that first link up top, they are just wrong? Man, who can you trust these days :).
No, they are not wrong. Take this example from that site
GET http://www.example.com/customers/33245/orders
Here, customers, 33245 and orders are not query parameters, they are resource endpoints, or uri nodes as they call them on your restapitutorial.com
If you do
GET http://www.example.com/customers you get all customers
GET http://www.example.com/customers/33245 you get customer 33245
GET http://www.example.com/customers/33245/orders you get customer 33245's orders
They all return 0 or more resources. If you were to apply a query to for example the first one and you wanted to GET all customers with John as first name, you would do this
GET http://www.example.com/customers?firstname=John
In the last example in your question, it would be written as GET http://www.example.com/customers/firstname/john instead, which is wrong in terms of restfulness. There is no customer resource 'firstname', and there is no firstname resource 'john'.
There are customers whose firstname is 'john' and you would GET them with
GET http://www.example.com/customers?firstname=John
I have REST API URL structure similar to:
/api/contacts GET Returns an array of contacts
/api/contacts/:id GET Returns the contact with id of :id
/api/contacts POST Adds a new contact and return it with an id added
/api/contacts/:id PUT Updates the contact with id of :id
/api/contacts/:id PATCH Partially updates the contact with id of :id
/api/contacts/:id DELETE Deletes the contact with id of :id
My question is about:
/api/contacts/:id GET
Suppose that in addition to fetching the contact by ID, I also want to fetch it by an unique alias.
What should be URI structure be if I want to be able to fetch contact by either ID or Alias?
If you're alias's are not numeric i would suggest using the same URI structure and figuring out if it's an ID or an alias on your end. Just like Facebook does with username and user_id. facebook.com/user_id or facebook.com/username.
Another approach would be to have the client use GET /contacts with some extra GET parameters as filters to first search for a contact and then looking up the ID from that response.
Last option i think would be to use a structure like GET /contacts/alias/:alias. But this would kinda imply that alias is a subresource of contacts.
The path and query part of IRIs are up to you. The path is for hierarchical data, like api/version/module/collection/item/property, the query is for non-hierarchical data, like ?display-fields="id,name,etc..." or ?search="brown teddy bear"&offset=125&count=25, etc...
What you have to keep in mind, that you are working with resources and not operations. So the IRIs are resource identifiers, like DELETE /something, and not operation identifiers, like POST /something/delete. You don't have to follow any structure by IRIs, so for example you could use simply POST /dashuif328rgfiwa. The server would understand, but it would be much harder to write a router for this kind of IRIs, that's why we use nice IRIs.
What is important that a single IRI always belongs only to a single resource. So you cannot read cat properties with GET /cats/123 and write dog properties with PUT /cats/123. What ppl usually don't understand, that a single resource can have multiple IRIs, so for example /cats/123, /cats/name:kitty, /users/123/cats/kitty, cats/123?fields="id,name", etc... can belong to the same resource. Or if you want to give an IRI to a thing (the living cat, not the document which describes it), then you can use /cats/123#thing or /users/123#kitty, etc... You usually do that in RDF documents.
What should be URI structure be if I want to be able to fetch contact
by either ID or Alias?
It can be /api/contacts/name:{name} for example /api/contacts/name:John, since it is clearly hierarchical. Or you can check if the param contains numeric or string in the /api/contacts/{param}.
You can use the query too, but I don't recommend that. For example the following IRI can have 2 separate meanings: /api/contacts?name="John". You want to list every contact with name John, or you want one exact contact. So you have to make some conventions about this kind of requests in the router of your server side application.
I would consider adding a "search" resource when you are trying to resolve a resource with the alias:
GET /api/contacts/:id
and
GET /api/contacts?alias=:alias
or
GET /api/contacts/search?q=:alias
First of all, the 'ID' in the URL doesn't have to be a numerical ID generated by your database. You could use any piece of data (including the alias) in the URL, as long as its unique. Of course, if you are using numerical ID's everywhere, it is more consistent to do the same in your contacts API. But you could choose to use the aliases instead of numeric IDs (as long as they are always unique).
Another approach would be, as Stromgren suggested, to allow both numeric IDs and aliases in the URL:
/api/contacts/123
/api/contacts/foobar
But this can obviously cause problems if aliases can be numeric, because then you wouldn't have any way to differentiate between an ID and a (numeric) alias.
Last but not least, you can implement a way of filtering the complete collection, as shlomi33 already suggested. I wouldn't introduce a search resource, as that isn't really RESTful, so I'd go for the other solution instead:
/api/contacts?alias=foobar
Which should return all contacts with foobar as alias. Since the alias should be unique, this will return 1 or 0 results.
I'm running a query vs the Google Places RadarSearch API and don't entirely understand the results. I'm trying to find nearby Tesco Supermarkets. My query is structured like this:
https://maps.googleapis.com/maps/api/place/radarsearch/xml?location=51.503186,-0.126446&types=store&keyword=tesco&name=tesco&radius=5000&key=XXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXX
I've tried a bunch of variations of the fields types, keyword and name. None of the results are Tesco stores. Am i missing something?
The Google docs show the fields as:
keyword — A term to be matched against all content that Google has indexed for this place, including but not limited to name, type, and address, as well as customer reviews and other third-party content.
name — One or more terms to be matched against the names of places, separated by a space character. Results will be restricted to those containing the passed name values. Note that a place may have additional names associated with it, beyond its listed name. The API will try to match the passed name value against all of these names. As a result, places may be returned in the results whose listed names do not match the search term, but whose associated names do.
I always get the maximum of 200 results which maybe includes 1 or 2 Tescos. When I check on Google maps there are 10 Tescos in the radius I am searching. It's as if the api is ignoring the name field. It doesn't matter what I populate in the name field, I still get the same results
UPDATE: Seems this is a known bug https://code.google.com/p/gmaps-api-issues/issues/detail?id=7082
maybe I am wrong, but I believe it is a commercial issue, google will show all business filtering them with a particular criteria they are no publishing the rules, for example in your search, the type you used was "store" , so they are returning to you all stores, and using the name or keyword in their own way who knows which criteria they are internally using, and there is something else, on the API description, the sample that they provide for radar search shows the name of the place in the result, but in the tests i am doing, they are not even sending the name, so you couldn't iterate those results, and filter by your own, for you to get the name, you have to do another call using:
https://maps.googleapis.com/maps/api/place/details/json?placeid=ChIJq4lX1doEdkgR5JXPstgQjc0&key=YOUR_KEY
Maybe there is another way but I don't see it.
I find the radar search is returning strange results today. It worked differently a couple of days ago.
The keyword-parameter has no effect at the moment and I have breaking integration-tests that were working before. I hope this is a temporary issue.
I filed a bug report for it: https://code.google.com/p/gmaps-api-issues/issues/detail?id=7086
I'm trying to use Freebase to list tourist attractions for cities by relevance.
Using the Topic API, it's simple to retrieve results for a certain city using its MID (e.g. "/m/04jpl" for London)
https:// www.googleapis.com/freebase/v1/topic/m/04jpl/?&filter=/travel/travel_destination/tourist_attractions
However, this gives a limited 10 results. The response ends with "count": 87.0". How do I get all 87? It's possible to click a "87 values total" link on London's Freebase page. Effectively, I want to do the same here.
I realise I could use MQL, but I want the results to be ranked by relevance, not by timestamp. Using the Search API, it's possible to rank by freebase, entity or schema, so I'd rather use that.
First, I looked at the Search Output schema for the Search API. However, even outputting "all" didn't produce Tourist Attraction results. Using metaschema with the Search API DID work. I used "part_of" to select London. However, it only works for some locations:
https:// www.googleapis.com/freebase/v1/search?limit=50&filter=(all%20type:/travel/tourist_attraction%20part_of:/m/04jpl)&indent=true
What I REALLY want to be able to do is make it work for a relatively unknown location like "Loughborough" (MID /m/01z21p). As you can see, substituting /m/04jpl for /m/01z21p produces no results:
https:// www.googleapis.com/freebase/v1/search?limit=50&filter=(all%20type:/travel/tourist_attraction%20part_of:/m/01z21p)&indent=true
Looking at "Loughborough", we see that its tourist attraction like "Loughborough Town Hall" has a "/travel/tourist_attraction/near_travel_destination" of "Loughborough". How would I compose this filter?
I want something like the following (that actually works):
https:// www.googleapis.com/freebase/v1/search?limit=50&filter=(all%20type:/travel/tourist_attraction)&filter=(/travel/tourist_attraction/near_travel_destination:/m/01z21p)&indent=true
Thanks!
NOTE: To enter the links into your browser you need to remove the space between the https:// and www. I would have done so, but I don't have the required permissions here yet to post more than 2 links.
I solved this problem using 2 Freebase API calls.
1) An MQL query that gets a list of all the tourist attractions for a particular MID. These results are not ranked in any useful way. I am also returning the result number to make processing a little easier later
https://www.googleapis.com/freebase/v1/mqlread?query={"mid":"/m/04jpl","/travel/travel_destination/tourist_attractions":[{"mid":null}],"resultnumber:/travel/travel_destination/tourist_attractions":[{"return":"count"}]}
The list of returned MIDs are then used to create a new query (using a for loop). You must enter all MIDs returned from the above query, so that they can all be ranked together.
2) https://www.googleapis.com/freebase/v1/search?limit=10&filter=(any%20mid:/m/0gsxw%20mid:/m/01d_0p%20mid:/m/07gyc)&scoring=entity
It's best to choose a return format that just returns MIDs, to ensure that loading times aren't extensive.
You then have a ranked list of MIDs! You'll need one final query to return whatever details you desire.
I hope this has proved helpful.
I have a business requirement where we need to do somce crazy name matching against records stored in the database and I was wondering if there is any easy way to do it using SQL Server.
Name Stored in the DB : Austin K
Name to be Matched from UI : Austin Kierland
That's just a sample. In reality, there could be whole lot of different permutations and combinations.
If it's other way round, I could've used wild character but in this case, the name in the database is smaller than the search criteria.
Any suggestions?
Realistically - no. Databases were meant for comparing absolute values, not for messy comparisons. The way they store their data internally just isn't fit for really messy matching. Actually even a superpowerful dedicated search engine like Google, that has a LOT of messy matching features, wouldn't be able to pull off your example without prior knowledge.
I don't know how the requirement is precisely worded, but I'd either shoot the feature request with "technically impossible", or implement a rule set for which messy matches are tried - for your example, you could easily 'hard code' that multiple searches are executed when capitalized words are entered, shortening them so a single letter. No idea if that's a solution to your problem though.
You can do a normal search using the LIKE operator which determines whether a specific character string matches a specified pattern. The problem you will run into is the probability of the returning of multiple records or incorrect people. I've had similar requirement myself for a business app and the best solution to the issue is to require other qualifying values rather then just name. If you do a partial name search without other qualifying data you are certainly going to come across the false positive matches and/or multiple records. In my case I built a web service that checks eligibility allowing text search for first & last name but also added date of birth, primary person SSN, and gender which ensured the matching person was in deed the person intended to search for. If my situation was like yours in which name was the only search criteria my recommendation to the business would be we cannot perform the search until qualifying data is entered into the database otherwise there is no accurate way to query the results they are looking for.