Scenario 1
In my web application say for there is a screen for adding an employee to system. As soon as user tabs after entering name of the employee, it generates the employee code automatically (which is the next field) based on some logic and already present records in the database.
Now I want to expose rest API for this application so that third party devs can build on top of it. So, I will have a resource called as /Employee which will respond for GET, PUT and DELETE verbs. But when a client needs to autofill the code, which is a GET operation, it will be on what resource? Should I make a new resource /EmployeeCodeFor/{Name} or I should get it on /Employee/{Name}/GenerateCode? If I go with /Employee/{Name}/GenerateCode then what about my resource to GET, PUT and DELETE for Employee i.e. actually /Employee/{Id}?
Scenario 2
Here lets take the case of a stackoverflow post. So lets say the resource would be /Post/{Id}. In the same way as in the previous example it lists me possible duplicate question as soon as I tab out of the Title field.
Again on what URL I should get those possible duplicates?
I can't think of more scenarios just now. But many such kind of scenarios may come up in real life application development. How to implement them in RESTful way?
Update on scenario 1
Code and Id are two different fields. Id is primary key, code can be duplicate across departments just to illustrate. Also to generate a code, name should be provided first. So, if user types a name "FirstName LastName" then server might generate FL003 as code assuming that there are already two more employees with firstname starting from F and lastname starting from L in the said department. Department can be identified based on the logged in user.
One way to allow the server an opportunity to pre-fill a bunch of elements in a new resource is to do
POST /Employees
{with empty body}
=>
201 Created
Location: http://example.org/employee/3443
<Employee Id="3443">
<Code>E1001</Code>
<FirstName></FirstName>
<LastName></LastName>
</Employee>
This gives the server one chance to provide default values. If you are looking for a more interactive way for the server to provide feedback during the input, I have another approach but it will take quite a bit more explaining.
Scenario 1
Let say your employee code is a unique identifier. In this case, to get it, you would allow the user to complete any field for the new employee and then make a POST. The server would generate the code and respond to the POST with a link to /Employee/{generated_code} which is the record for your newly created employee.
A GET on /Employee would return a list of all employees. A GET on /Employee/{a_code} will give you the employee detail.
Scenario 2
You could have some kind of query on the /Post collection like /Post?title_like={question_title}. A GET /Post?title_like=REST How to would return you a list of all questions containing "REST How to".
Related
I am trying to write a query that 1) works and 2) shows meaningful information.
However, I can't seem to complete both scenarios. Both bits of code do work to a degree. My SQL query does work by showing all the useful information a user wants but when you click the edit button it doesn't link properly so it won't allow the user to update that row. The other shows only keys and rowid but when you click edit does show the information and allows it to be updated.
So as not to get another down-voted question, I have taken pictures of each scenario to show the problem, but, ultimately, I need to show meaningful information: an id or key isn't meaningful to the vast majority of users.
Here is my code
SELECT APPLICATIONS.APP_ID, APPLICATIONS.SRN, STUDENTS.SURNAME, STUDENTS.FORENAME, APP_STATUS.STATUS, METHODS.METHOD, JOBS.JOB_TITLE, APPLICATIONS.APP_DATE
FROM APPLICATIONS
JOIN STUDENTS
ON APPLICATIONS.SRN = STUDENTS.SRN
JOIN APP_STATUS
ON APPLICATIONS.STATUS_ID = APP_STATUS.STATUS_ID
JOIN METHODS
ON APPLICATIONS.METHOD_ID = METHODS.METHOD_ID
JOIN JOBS
ON APPLICATIONS.JOB_ID = JOBS.JOB_ID;
and here are the pictures of it in action
below is the code that does not show meaningful information but does work.
select "ROWID",
"APP_ID",
"SRN",
"STATUS_ID",
"METHOD_ID",
"JOB_ID",
"APP_DATE"
from "#OWNER#"."APPLICATIONS"
If i knew how to properly use rowid i am sure this is a simple feat but i dont so if i could get any help it would be useful
//edit
who ever renamed this to Application Expression why? what i am using is Apex Application Express it was relevant information that got changed to something wrong which might make it hard for someone with a similar problem to find later.
In the second, simple query, apex can determine which table (and record) you are trying to edit.
In the first query, with the joins, it can't tell which of the five tables in query you want to edit. You probably want to have the edit link pass the primary key of the row from APPLICATIONS to the child page. You would need to build into that page any logic (lists of values etc) that map lookup tables (such as status) to the values needed in the APPLICATIONS table.
I have 2 tables, User table and User_token table, they are one to one/none relatonship, not sure how to create this RESTful API.
i prefer to setup
# to get user attributes
GET /users/123
# to get user's token
GET /users/123/token
or should i create
# to get user attributes and token by JOIN the table
GET /users/123
the argument we have here, if we are doing the first setup, which i like it, it takes thousands of API requests compare to second one
that is depend you requirement.
for example if you need User Attributes and Token every time than
# to get user attributes and token by JOIN the table
GET /users/123
is better.
other wise another approach is good to get required data when needed.
REST has nothing to do with your database structure.
Your resources can contain properties or sub-resources. Every resource has at least one resource identifier (URL).
So in your case the GET /users/123 is a valid solution.
I'm new to server side web development and recently I've been reading a lot about implementing RESTful API's. One aspect of REST API's that I'm still stuck on is how to go about structuring the URI hierarchy that identifies resources that the client can interact with. Specifically I'm stuck on deciding how detailed to make the hierarchy and what to do in the case of resources being composed of other resource types.
Here's an example that hopefully will show what I mean. Imagine we have a web service that lets users buy products from other users. So in this simple case, there are two top level resources users and products. Here's how I began to structure the URI hierarchy,
For users:
/users
/{id}
/location
/about
/name
/seller_rating
/bought
/sold
For products:
/products
/{id}
/name
/category
/description
/keywords
/buyer
/seller
In both of these cases objects in each hierarchy reference a subset of the objects in the other hierarchy. For example /users/{id}/bought is a list of the products that some user has bought, which is a subset of /products. Also, /products/{id}/seller references the user that sold a specific product.
Since these URI's reference other objects, or subsets of other objects, should the API support things like this: /users/{id}/bought/id/description and /products/{id}/buyer/location? Because if those types of URI's are supported, what's to stop something like this /users/{id}/bought/{id}/buyer/bought/{id}/seller/name, or something equally convoluted? Also, in this case, how would you handle routing since the router in the server would have to interpret URI's of arbitrary length?
The goal is to build convenient resource identifiers, don't try to cross-reference everything. You don't have to repeat your database relations in URL representation :)
Links like /product/{id}/buyer should never exist, because there already is identifier for that resource: /user/{id}
Although it's ok to have /product/{id}/buyers-list because list of buyers is a property of product that does not exist in other contexts.
You should think of it in a CRUD fashion, where each entity supports Create, Read, Update, and Delete (typically using GET, POST, PUT, and DELETE HTTP verbs respectively).
This means that your endpoints will typically only go one level deep. For instance
Users
GET /users - Return a list of all users (you may not want to make this publically available)
GET /users/:id - Return the user with that id
POST /users - Create a new user. Return a 201 Status Code and the newly created id (if you want)
PUT /users/:id - Update the user with that id
DELETE /users/:id - Delete the user with that id
Going into more detail, such as /users/:id/about is likely not necessary. While it may work, it may be getting slightly overspecific.
Perhaps in your case you could add in:
GET /users/:id/bought - Array of products that the user bought
GET /users/:id/sold - Array of products that the user sold
where you could return a list of id's (which can be fetched through the products API), or you could populate the Products before sending them back if you wish. If you do choose to populate them, you probably should not then populate users referenced by each product. This will lead to circular includes and is wrong.
And for Products, in your sitation I would use:
GET /products- Return a list of all products
GET /products/:id - Return the products with that id
POST /products- Create a new product. Return a 201 Status Code and the newly created id (if you want)
PUT /products/:id - Update the product with that id
DELETE /products/:id - Delete the product with that id
GET /products/:id/buyers - Array of who bought the product
GET /products/:id/sellers - Array of everyone selling the product
I am fairly new to Silverlight and RIA services, and I am trying to build a small project to understand it. So basically I created a Business Application, and I have the normal Login screen where I can add a user. That is fine and I can add a user and get him into the aspnet_Users table. Now I have created some extra fields, like Mob No, Tel No, DOB, Locality etc, which I have put in a table I have created called the UserProfile, and my idea is to get the username that was registered, and insert it into my UserProfile table with the other relevant data.
So I created a page called Profile.xaml, I created a UserProfileDomainService.cs where I have just one query, to get the user profile data from the table, and then created a Details DataGrid on my page, and the QueryName in my case is GetUserProfilesQuery(). Now what i wish to do is, get the user logged in, get his username, and check in my table to see if there is already data in the table. If there is populate the fields on the DataGrid with data, so that the user can modify this data, and if not, allow the user to insert data into the table.
So I have created a UserProfileViewModel class, and I want to create the query to get the data relevant to this user. However I got stuck on how to do all this, and how to get the user logged in.
Can anybody give me some advice or point me to some tutorials on how I can achieve this?
Thanks a lot and your help is very much appreciated.
In your domain service query you can use ServiceContext.User.Identity.Name to get the information specific to that user to include in your db query. I do something similar in our project.
We use entity framework so the LINQ to Entities query looks like:
return this.ObjectContext.UserSnapins
.Include("Snapin.EvolutionModule")
.Where(si => si.User.UserName == ServiceContext.User.Identity.Name)
.OrderBy(si => si.PageOrder);
I'm currently logging all actions of users and want to display their actions for the people following them to see - kind of like Facebook does it for friends.
I'm logging all these actions in a table with the following structure:
id - PK
userid - id of the user whose action gets logged
actiondate - when the action happened
actiontypeid - id of the type of action (actiontypes stored in a different table - i.e. following other users, writing on people's profiles, creating new content, commenting on existing content, etc.)
objectid - id of the object they just created (i.e. comment id)
onobjectid - id of the object they did the action to (i.e. id of the content that they commented on)
Now the problem is there are several types of actions that get logged (actiontypeid).
What would be the best way of retrieving the data to display to the user?
The easiest way out would be gabbing the people the user follows dataset and then just go from there and grab all other info from the other tables (i.e. the names of the users the people you're following just started following, names of the user profiles they wrote on, etc.). This however would create a a huge amount of small queries and trips to the database in a while loop. Not a good idea.
I could use joins to retrieve everything in one massive data set, but how would I know where to grab the data from in just one query? - there's different types of actions that require me to look into several different tables to retrieve data, based on the actiontypeid...
i.e. To get User X is now following User Y I'd have to get my data (User Y's username) from the followers table, whereas User X commented on content Y would need me to look in the content table to get the content's title and URL.
Any tips are welcome, thanks!
Consider creating several views for different actiontypeids. Union them to have one full history.