asp.net web api - How to transform OData filter to a LINQ expression? -

-

i'm trying extract filter expression odataqueryoptions can use in business logic class.

public pageresult<poco> get(odataqueryoptions odataqueryoptions) {     expression<func<poco, bool>> myexpression = ... // do here?      var result = _mybusinesslogic.search(myexpression);     return new pageresult<poco>(result, null, null); }

i took @ blog describing translating query hql here , think (at least hope) that's overkill i'm trying do.

i need filter expression in expression<func<poco, bool>> form. tried playing applyto() can't quite it. appreciated.

we have filterbinder class suits needs internal unfortunately. nevertheless simple trick hold of $filter expression,

public static class odataqueryoptionsextensions {     public static expression toexpression<telement>(this filterqueryoption filter)     {         iqueryable queryable = enumerable.empty<telement>().asqueryable();         queryable = filter.applyto(queryable, new odataquerysettings());         return queryable.expression;     } }

in case, can do,

public pageresult<poco> get(odataqueryoptions odataqueryoptions) {     expression<func<poco, bool>> myexpression = odataqueryoptions.filter.toexpression<poco>();      var result = _mybusinesslogic.search(myexpression);     return new pageresult<poco>(result, null, null); }

notice expression contains looks more this, sotests.customer[].where($it => conditional-expression). so, might have extract conditional expression lambda.


Comments

Post a Comment

Popular posts from this blog

java - Jmockit String final length method mocking Issue -

-
using jmockit 1.2 jar, trying mock string's length method getting unexpected invocation exception: failed: test java.lang.illegalstateexception: missing invocation mocked type @ point; please make sure such invocations appear after declaration of suitable mock field or parameter @ stringdemo.testa$1.<init>(testa.java:17) @ stringdemo.testa.test(testa.java:13) i using testng: @test public void test() throws exception { new expectations() { @mocked("length") string astring; { astring.length(); result = 2; } }; system.out.println(a.showa("test")); } } actual class a: public class { public static int showa(string str){ int a= str.length(); return a; } } this wrong way of recording expected results. shouldn't mock , record string's length() method, record showa() instead. here solution @suppresswarnings("unused...
Read more

What is the difference between data design and data model(ERD) -

-
i have google question , find answer in day. know, data design many many table have list column,and mark pk , fk. why er-diagram have find this? data design process of designing database. main output of data design detailed logical data model of database. some people data design includes of needed logical , physical design choices , physical storage parameters needed generate design in data definition language. technically, database analysis, database analysts (dbas) trained do. while person can both data design , database analysis, these 2 different tasks. data design models data. database analysis takes model , applies 1 or more database engines (relational, hierarchical, nosql). a logical data model 1 of main outputs of data design. data model represented entity relationship diagram, or er diagram.
Read more

ios - Can NSManagedObject conform to NSCoding -

-
i need transfer single object across device. right converting nsmanagedobject dictionary , archiving , sending nsdata. upon receiving unarchiving it. transfer nsmanagedobject archiving , unarchiving instead of creating intermediate data object. @interface test : nsmanagedobject<nscoding> @property (nonatomic, retain) nsstring * title; @end @implementation test @dynamic title; - (id)initwithcoder:(nscoder *)coder { self = [super init]; if (self) { self.title = [coder decodeobjectforkey:@"title"]; //<crash } return self; } - (void)encodewithcoder:(nscoder *)coder { [coder encodeobject:self.title forkey:@"title"]; } @end nsdata *archivedobjects = [nskeyedarchiver archiveddatawithrootobject:testobj]; nsdata *objectsdata = archivedobjects; if ([objectsdata length] > 0) { nsarray *objects = [nskeyedunarchiver unarchiveobjectwithdata:objectsdata]; } the problem above code is. crashes @ self.title in initwithcoder sa...
Read more