My code is like below:
server.get('/currency/:code', currency.find);
server.get('/currency/rates', currency.rate_getall);
Whenever I try to reach [/rates] endpoint, the server will assume I am passing parameter to '/currency/:code' route. How can I fix this? Thank you.
Ryan
If you can I would consider changing up your rest interface just a little.
server.get('/currency/:code', currency.find);
server.get('/currency/rates/:type', currency.rate);
That way it solves your initial problem and allows for flexibility in the future if you just want to return a rate for a particular currency.
Inside your currency.rate function you could check for either an id or the literal 'all' and return what is appropriate.
Related
I'm trying to connect my NestJs Project with a Oracle db and I'm using TypeORM and the status of connection is ok but I don't know how I can connect with a function. This function is into of a package and at the same time this package is into of a schema. The structure is like:
mySchema:
--------->myPackage:
-------------------->myFunction(id)
In the NestJS code I'm define this import in the AppModule file:
When I try to use the entity I don't know what method can I use to connect with my function. With the ESLint I get the next methods:
I hope to be clear and thanks for all!
In you last picture you’re trying to make a request to the database and as you can see, when you mentioned the testRepository and dots(.) now you have to tell him what you want to do in your database and in the suggested list you have all the possible possibilities.
So if you want to get or fetch data from you database, you will use testRepository.find() this will give you everything in that particular entity. To do that, you have to do something like below, before that you code has something that I have never seen in Nest, (public); if it does exist but I won’t use that in my Example since I don’t know it in Nest and also; you have started writing without (return) I don’t know how you’re expecting to return what you will get from your database.
Here is my example:
in your controller:
#Get() AnyThing(): Promise<TestEntity[]> {return this.DaobscsService.whatEver(); }
And in your service:
#InjectRepository(TestEntity) private readonlytestRepository: Repository<TestEntity>, ) {}
async whatEver(): Promise<TestEntity[]> {return await this.testRepository.find();}
What ever name you gonna use instead (whatEver()) in the service that have used, remember to use the same name in your controller pointing to service (this.Boa...Service.(The name here) OOP system’s you know it I hope
This example is to get or fetch so if you don’t have any thing in your database then you will get nothing! if that’s not what u want then command with a full version of what exactly is your issue, what u expected and code from controller, service, and module.
I have a route definition in function.json: entity/{paramName}
When I make a GET request: http://localhost:7071/api/entity/50043e-315
In context.bindingData.paramName I get surprising 5.0043e-311, while context.req.params.paramName contains 50043e-315.
I noticed that here both ways of reading can be used; and here the same is meant, though the links are dead by now, while the example here mentions only context.bindingData.
Question: What is more preferable? And what is the difference?
I believe the problem here is that the somewhere (if I were to make a guess, here) the param is being parsed as a double before being stored as binding data. But when fetching it from the request object, it is fetched as a string from the URL directly. Hence the difference.
I believe there are only a few cases where this might happen and this is one of them.
Here is below my code of route:-
app.get('/server/lead/get/:id?', leadCtrl.get);
app.get('/server/lead/filter/:filterQuery', leadCtrl.get);
As you see above i am using different route to access same controller method leadCtrl.get.
Now, i want something like route app.get('/server/lead/get/:id?:filter?', leadCtrl.get);. So, i can get params either req.params.id or req.params.filter but only one at a time.
What you asked in the question is not possible in the form that you describe it.
Now, i want something like route
app.get('/server/lead/get/:id?:filter?', leadCtrl.get);. So, i can get
params either req.params.id or req.params.filter but only one at a
time.
Your router would have no way to differentiate those two parameters. If it got a request to /server/lead/get/X then what is X? A filter or an ID?
Your options
You have few solutions here:
You can either keep using two routes like you did before.
You can use a common parameter for both cases as Robert explained in the comments.
Or you can use what seems to me the perfect solution for your use case - named query parameters - just use a route /server/lead/get and use query parameters to pass id and the filter.
Example URLs:
/server/lead/get?id=xxx
/server/lead/get?filterQuery=xxx
You will only have to make sure in your handler that only one of those two are set at a time with something like:
if (req.query.id && req.query.filterQuery) {
// respond with error
}
You can even mix the two if you have app.get('/server/lead/get/:id?') route you can have the id in the route and filterQuery as a query parameter. Now the URLs would be:
/server/lead/get/xxx (for id)
/server/lead/get?filterQuery=xxx (for filter)
For more info see: http://expressjs.com/en/api.html#req.query
Better way
If you follow some REST conventions then you can use:
app.get('/server/lead/:id') for one object with id (not optional)
app.get('/server/lead') for a list of objects (with optional filterQuery passed as a query parameter)
That way you would always know that when you access:
/server/lead/xxx - then it's one object with ID = xxx
/server/lead - then it's a list of any objects
/server/lead?filterQuery=xxx - then it's a list of objects that match the query
If you follow the REST conventions for things like this instead of inventing your own, it would be much easier for you to design the routes and handlers, and it would be much easier for other people to use your system.
You may also want to use plural /server/leads instead of /server/lead which is common with REST. That way it will be more obvious that leads is a list and leads/id is one of its elements.
For more info see:
https://en.wikipedia.org/wiki/Representational_state_transfer
http://www.restapitutorial.com/lessons/whatisrest.html
https://spring.io/understanding/REST
You have to realize that the following two routes match exactly the same:
app.get('/server/lead/get/:id?', leadCtrl.get);
app.get('/server/lead/get/:filter?', leadCtrl.get);
Express doesn't care about how you name the placeholders, so any requests for /server/lead/get/SOMEVALUE will always match the first (the one with :id).
You can add a distinction yourself, by only allowing a parameter to match a particular regular expression. From your code, it looks like :id should match MongoDB ObjectId's, so you can create a specific match for those:
app.get('/server/lead/get/:id([a-fA-F0-9]{24})?', leadCtrl.get);
If SOMEVALUE matches an ObjectId, it will call leadCtrl.get and populate req.params.id. If you also add another router for "the rest", you can also cover the req.params.filter case:
app.get('/server/lead/get/:filter?', leadCtrl.get);
As an aside: you're saying that you're passing JSON to the "filter" routes, in the URL. I would strongly suggest using a POST route for that, and post the JSON as request body content.
Since, I can get parameters from both the methods using a code similar to the one below:
req.params.<PARAM NAME> in single/many separate app.METHOD function(s)
(think this may result in code repetition)
&
app.params(<ARRAY>,<CALLBACK>) function, independent of the app.METHOD functions, and called if the URL contains any parameter (:id, :name .etc)
What are the use-cases to apply one over the other?
My best guess would be is using app.params for parameter validation or some sort of preprocessing. For example the express docs provide and example where you attach req.user information to the request using app.params and after that you can work directly with the user information instead of processing the parameter again. Using req.params would be more specific in terms of processing the specific query. For example I'd use req.params for a REST endpoint which should perform an operation by id (update/delete) as in general there shouldn't be any additional preprocessing involder.
I'm writing a REST api in node js that will execute a sql query and send the results;
in the request I need to send the WHERE conditions; ex:
GET 127.0.0.1:5007/users //gets the list of users
GET 127.0.0.1:5007/users
id = 1 //gets the user with id 1
Right now the conditions are passed from the client to the rest api in the request's headers.
In the API I'm using sequelize, an ORM that needs to receive WHERE conditions in a particular form (an object); ex: having the condition:
(x=1 AND (y=2 OR z=3)) OR (x=3 AND y=1)
this needs to be formatted as a nested object:
-- x=1
-- AND -| -- y=2
| -- OR ----|
| -- z=3
-- OR -|
|
| -- x=3
-- AND -|
-- y=1
so the object would be:
Sequelize.or (
Sequelize.and (
{x=1},
Sequelize.or(
{y=2},
{z=3}
)
),
Sequelize.and (
{x=3},
{y=1}
)
)
Now I'm trying to pass a simple string (like "(x=1 AND (y=2 OR z=3)) OR (x=3 AND y=1)"), but then I will need a function on the server that can convert the string in the needed object (this method in my opinion has the advantage that the developer writing the client, can pass the where conditions in a simple way, like using sql, and this method is also indipendent from the used ORM, with no need to change the client if we need to change the server or use a different ORM);
The function to read and convert the conditions' string into an object is giving me headache (I'm trying to write one without success, so if you have some examples about how to do something like this...)
What I would like to get is a route capable of executing almost any kind of sql query and give the results:
now I have a different route for everything:
127.0.0.1:5007/users //to get all users
127.0.0.1:5007/users/1 //to get a single user
127.0.0.1:5007/lastusers //to get user registered in the last month
and so on for the other tables i need to query (one route for every kind of request I need in the client);
instead I would like to have only one route, something like:
127.0.0.1:5007/request
(when calling this route I will pass the table name and the conditions' string)
Do you think this solution would be a good solution or you generally use other ways to handle this kind of things?
Do you have any idea on how to write a function to convert the conditions' string into the desired object?
Any suggestion would be appreciated ;)
I would strongly advise you not to expose any part of your database model to your clients. Doing so means you can't change anything you expose without the risk of breaking the clients. One suggestion as far as what you've supplied is that you can and should use query parameters to cut down on the number of endpoints you've got.
GET /users //to get all users
GET /users?registeredInPastDays=30 //to get user registered in the last month
GET /users/1 //to get a single user
Obviously "registeredInPastDays" should be renamed to something less clumsy .. it's just an example.
As far as the conditions string, there ought to be plenty of parsers available online. The grammar looks very straightforward.
IMHO the main disadvantage of your solution is that you are creating just another API for quering data. Why create sthm from scratch if it is already created? You should use existing mature query API and focus on your business logic rather then inventing sthm new.
For example, you can take query syntax from Odata. Many people have been developing that standard for a long time. They have already considered different use cases and obstacles for query API.
Resources are located with a URI. You can use or mix three ways to address them:
Hierarchically with a sequence of path segments:
/users/john/posts/4711
Non hierarchically with query parameters:
/users/john/posts?minVotes=10&minViews=1000&tags=java
With matrix parameters which affect only one path segment:
/users;country=ukraine/posts
This is normally sufficient enough but it has limitations like the maximum length. In your case a problem is that you can't easily describe and and or conjunctions with query parameters. But you can use a custom or standard query syntax. For instance if you want to find all cars or vehicles from Ford except the Capri with a price between $10000 and $20000 Google uses the search parameter
q=cars+OR+vehicles+%22ford%22+-capri+%2410000..%2420000
(the %22 is a escaped ", the %24 a escaped $).
If this does not work for your case and you want to pass data outside of the URI the format is just a matter of your taste. Adding a custom header like X-Filter may be a valid approach. I would tend to use a POST. Although you just want to query data this is still RESTful if you treat your request as the creation of a search result resource:
POST /search HTTP/1.1
your query-data
Your server should return the newly created resource in the Location header:
HTTP/1.1 201 Created
Location: /search/3
The result can still be cached and you can bookmark it or send the link. The downside is that you need an additional POST.