I have an issue regarding duplicate parameter in WebApi.
http://localhost:xxxxx/api/getbook?UserId=7 in this API Controller I have one parameter string UserId and works fine but if i do something like that
http://localhost:xxxxx/api/getbook?UserId=7?UserId=7 gets the result
So how to prevent duplicate parameter in API ?
A couple of things to note:
There would be an & character between the parameters i.e. http://localhost:xxxxx/api/getbook?UserId=7&UserId=7
The first parameter of the same name will be used by default if you are taking a model in to a controller method
If you are keen to throw some error when you discover duplicate parameter names then you could do the following:
var queryParameters = Request.GetQueryNameValuePairs()
.GroupBy(k => k.Key)
.Where(g => g.Count() > 1)
.Select(q => q.Key)
.ToList();
This will give you a List<string> of parameter names that appear more than once.
If you are interested in whether the parameter name and value combination is repeated (as in your example), then just GroupBy(k => k) instead and you will get a list of KeyValuePair to work with.
Related
LINQ newbie here.
I have a long LINQ query, called it MYLONGQUERY, that returns a collection of certain class instances. If the list is not empty, I want to return a property (MYPROPERTY) of the first instance; otherwise it returns some default value (DEFAULTPROPERTY). So the query looks like this
(0 != MYLONGQUERY.count()) ? MYLONGQUERY.FirstOrDefault().MYPROPERTY: DEFAULTPROPERTY
This works fine. However, I don't like the fact that I have to repeat MYLONGQUERY before and after "?". I have been trying Let and Into, but have not been able to get those to work. And it has to be Method Syntax, not Query Syntax. Suggestions? Appreciate it.
You have to select the property first, then you can specify the default-value with DefaultIfEmpty:
var prop = MYLONGQUERY
.Select(x => x.MYPROPERTY)
.DefaultIfEmpty(DEFAULTPROPERTY) // new default-value
.First(); // never exception
I am looking at routing to a Controller for GET URL whose parameters can vary in number or the order in which they appear in the URL. There could be many such combinations and I want to invoke the same controller action for all of these URLs
Examples of how my URLs could look like:
Route::get('route1/id/{id}',
'Controller1#controllerAction1');
Route::get('route1/id/{id}/name/{name}',
'Controller1#controllerAction1');
Route::get('route1/name/{name}',
'Controller1#controllerAction1');
Route::get('route1/id/{id}/name/{name}/orderby/{orderby}',
'Controller1#controllerAction1');
Route::get('route1/id/{id}/orderby/{orderby}',
'Controller1#controllerAction1');
Also in the Controller action, I ultimately want to break this query string into an array. For the second example mentioned above, I want the query string id/{id}/name/{name} to be converted to array ('id' => {id}, 'name' => {name})
To invoke the same controller action for all different variations of the URLs, I have the following code in my routes.php:
Route::get('route1{all}', 'Controller1#controllerAction1')->where('all', '.*')
which seems to invoke the "controllerAction1" of Controller1 for the different types of URLs mentioned above.
And in the function controllerAction1, I am doing
$route_input = Route::input('all');
var_dump($route_input);
which prints "/id/1/name/xyz" when I hit http://example.com/laravel/public/route1/id/1/name/xyz
I would like to know if:
Doing Route::get('route1{all}',
'Controller1#controllerAction1')->where('all', '.*') is the right
method to invoke same action for variable combination of get
parameters? Does Laravel offer any function to convert
"/id/1/name/xyz" to array('id' => 1, 'name' => 'xyz') or I need to
write custom function? Is there a better way to achieve my
requirements?
I believe not. Plus, in this way you won't be able to understand which values are being passed.
Even if there is one, I think you don't actually need to pass the array. IMHO, I prefer to keep the items separate, then manipulate them from the controller. This is just my personal suggestion, but if you need an array of data, why don't you use a POST method? (the only right answer, is that you want the users to be able to save the link :P )
The complicated part about your request, is that you want to keep everything under the same controller action, which messes the routes. I would try this (in your routes.php):
Route::pattern('id', '[0-9]+');
Route::pattern('name', '[a-Z]+');
Route::get('route1/{id}/{name?}/{orderby?}', 'Controller1#controllerAction1');
Route::get('route1/{name}/{orderby?}', 'Controller1#controllerAction1');
In this way:
you can have a route with just the ID, where NAME and ORDERBY are optional
if no ID is passed, you can have a route with only NAME, where ORDERBY is optional
Note how this is different from your URLs: it's much more complicated to put the routes as you wrote them id/{id}/name/{name}, than in the way I proposed {id}/{name}. If you need them exactly your way, why don't you call the links passing the variables from the GET function as follows? http://www.yoursite.com/route1?id=xxxx&name=yyyy&orderBy=zzzz
To have the route parameters convert from a set of individual parameters to an array that contains all the parameters in Laravel 5, you can call this from the Controller:
$routeParameters = $this->getRouter()->getCurrentRoute()->parameters()
For the route definition
Route::get('route1/id/{id}/name/{name}', 'Controller1#controllerAction1');
if a user hits the route with the following: /route1/id/2/name/john
$routeParameters would equal
array(id => 2, name => 'john')
Being new to attribute routing, I'd like to ask for help getting this to work.
This test is a simple dynamic DB table viewer: Given a table name (or stored query name or whatever) and optionally some WHERE parameters, return query results.
Table COMPANIES (one of any number of tables which has an associated SELECT query stored somewhere, keyed by table name):
ID NAME HQ INDUSTRY
1 Apple USA Consumer electronics
2 Bose USA Low-quality, expensive audio equipment
3 Nokia FIN Mobile Phones
Controller:
[Route("view/{table}/{parameters}")]
public object Get(string table, Dictionary<string, string> parameters) {
var sql = GetSql(table);
var dbArgs = new DynamicParameters(parameters);
return Database.Query(sql, dbArgs); // Return stuff/unrelated to problem
}
SQL stored in some resource or table. Obviously the parameters must match exactly:
SELECT * FROM companies
WHERE name = :name
-- OR hq = :hq
-- OR ...etc. Doesn't matter since it never gets this far.
Request (Should look clean, but the exact URL format isn't important):
www.website.com/view/companies?hq=fin --> 404: No matching controller
www.website.com/view/companies/hq=fin --> parameters is null
www.website.com/view/companies/hq=fin&name=nokia --> Exception: A potentially dangerous Request.Path value was detected from the client (&).
When I use: [Route("view/{table}{parameters}")] I get:
A path segment cannot contain two consecutive parameters. They must be separated by a '/' or by a literal string. Parameter name: routeTemplate. Makes sense.
My question is: How do I accept a table name and any number of unknown parameters in the usual key1=val1&key2=val2 form (not some awkward indexed format like the one mentioned here) which will be later bound to SQL parameters, preferably using a vanilla data structure rather than something like FormCollection.
I don't think that binding URL parameters to a Dictionary is built-in to the framework. I'm sure there's a way to extend it if you wanted to.
I think quickest (but still acceptable) option is to get the query string parameters using Request.GetQueryNameValuePairs() like this:
[Route("view/{table}")]
public object Get(string table) {
Dictionary<string, string> parameters = Request.GetQueryNameValuePairs()
.ToDictionary(x => x.Key, x => x.Value);
var sql = GetSql(table);
var dbArgs = new DynamicParameters(parameters);
return Database.Query(sql, dbArgs); // Return stuff/unrelated to problem
}
I want to do something like
from table1
where col5="abcd"
select col1
I did like
query_ = From g In DomainService.GetGEsQuery Select New GE With {.Desc = g.codDesc}
"This cause a runtime error, i tried various combinations but failed"
please help.
I'm assuming your trying to do this on the client side. If so you could do something like this
DomainService.Load(DomainService.GetGEsQuery().Where(g => g.codDesc == "something"), lo =>
{
if (lo.HasError == false)
{
List<string> temp = lo.Entities.Select(a => a.Name).ToList();
}
}, null);
you could also do this in the server side (which i would personally prefer) like this
public IQueryable<string> GetGEStringList(string something)
{
return this.ObjectContext.GE.Where(g => g.codDesc == something).Select(a => a.Name);
}
Hope this helps
DomainService.GetGEsQuery() returns an IQueryable, that is only useful in a subsequent asynchronous load. Your are missing the () on the method call, but that is only the first problem.
You can apply filter operations to the query returned using Where etc, but it still needs to be passed to the Load method of your domain context (called DomainService in your example).
The example Jack7 has posted shows an anonymous callback from the load method which then accesses the results inside the load object lo and extracts just the required field with another query. Note that you can filter the query in RIA services, but not change the basic return type (i.e. you cannot filter out unwanted columns on the client-side).
Jack7's second suggestion to implement a specific method server-side, returning just the data you want, is your best option.
when using a MVC 3 collection that uses IEnumerable, is there a way to make small queries work to find single values? I've been experimenting with little success.
I have a collection of settings that have descriptions and settings. The problem is exposing one of them, as each is unique. I've tried something like this:
var appl = _service.GetSettings(id, app); //Call to service layer & repository
appl.Select(a => a.setting_value.Where(a.setting_name.StartsWith("Login")));
With little success (unless I'm missing something). Is it possible to select one item from an enumerable collection and either pass it to a ViewBag or ViewData object? What I would like to do is something like the following:
var appl = _service.GetSettings(id, app); //Call to service layer & repository
ViewBag.Login = appl.Select(a => a.setting_value.Where(a.setting_name.StartsWith("Login")));
And pass this to the view, since I have a view that now combines a collection with single values.
The following seems to work within the view:
Application Name #Html.TextBox("application_name", #Model.FirstOrDefault().app_name)
But I'm not sure if this violates separation of concerns. Am I on the wrong path here? Thank you!
EDIT: Here is what I needed. The answers below got me very very close +1 +1
ViewBag.Login = appl.Where(a => a.setting_name.StartsWith("Login")).FirstOrDefault().setting_value
ViewBag.Login = appl.Select(a => a.setting_value.Where(a.setting_name.StartsWith("Login"))).FirstOrDefault();
This will select the first object that matches your criteria and return a single result or null
var appl = _service.GetSettings(id, app);
ViewBag.Login = appl
.Where(a => a.setting_name.StartsWith("Login"))
.FirstOrDefault();