I'm having a problem when use AutoMapper
my code:
public static IQueryable<IGrouping<Int64, GroupTimeSheetViewModel>> ToListGroupViewModel(this IQueryable<IGrouping<Int64, GroupTimeSheet>> entity)
{
return Mapper.Map<IQueryable<IGrouping<Int64, GroupTimeSheet>>, IQueryable<IGrouping<Int64, GroupTimeSheetViewModel>>>(entity);
}
when I run my code, I get error:
The value "System.Collections.Generic.List1[PG.Admin.Models.TimeSheetHeaders.GroupTimeSheetViewModel]" is not of type "System.Linq.IGrouping2[System.Int64,PG.Admin.Models.TimeSheetHeaders.GroupTimeSheetViewModel]" and cannot be used in this generic collection.
Parameter name: value
AutoMapper can't map queryables directly. If I were you, I'd use AutoMapper's LINQ projection capabilities. It uses LINQ to build out the Select projection. That way, your resultant LINQ would be something like:
dbContext.GroupTimeSheets
.GroupBy(ts => ts.Something)
.Project().To<GroupTimeSheetViewModel>()
.ToListAsync();
Related
I have the following (simplified) Entity SQL query:
SELECT VALUE a
FROM Customers AS a
WHERE a.Status NOT IN { 2, 3 }
The Status property is an enumeration type, call it CustomerStatus. The enumeration is defined in the EDMX file.
As it is, this query doesn't work, throwing an exception to the effect that CustomerStatus is incompatible with Int32 (its underlying type is int). However, I couldn't find a way to define a list of CustomerStatus values for the IN {} clause, no matter what namespace I prefixed to the enumeration name. For example,
SELECT VALUE a
FROM Customers AS a
WHERE a.Status NOT IN { MyModelEntities.CustomerStatus.Reject, MyModelEntities.CustomerStatus.Accept }
did not work, throwing an exception saying it could not find MyModelEntities.CustomerStatus in the container, or some such.
Eventually I resorted to casting the Status to int, such as
SELECT VALUE a
FROM Customers AS a
WHERE CAST(a.Status AS System.Int32) NOT IN { 2, 3 }
but I was hoping for a more elegant solution.
Oooh, you are writing Entity SQL directly. I see... Any reason you aren't using DbSet instead of writing Entity SQL by hand? Could always do
var statuses = new [] { Status.A, Status.B };
var query = context.SomeTable.Where(a => !statuses.Contains(a.Status)).ToList();
I am building an ASP.NET MVC application using the Repository pattern. A typical method in my Repository is as follows
public IList<T> Select<T>(string cacheKey, string Sql, object filter) where T: new()
{
IList<T> items = MemoryCache.Default.Get(cacheKey) as IList<T>;
if (items == null || !items.Any())
{
items = Connection.Select<T>(Sql, filter);
MemoryCache.Default.Add(cacheKey, items, DateTime.Now.AddMinutes(120));
}
return items;
}
and it is being used as follows
IEnumerable<OSADCOL> osadcols = Repository.Select<OSADCOL>("OSADCOLS__TblId=" + Id, "TBLid = #id", new { id = Id });
In the above mentioned example OSADCOL is a model in my app and represents a Table with the same name in my Database. The Connection.Select function is ORMlite function. I don't use Entity Framework for performance issues. My problem is the following. I am currently cashing the result set for future relevance but I am doing it in a hard coded way. I am caching the result set for 2 hours. It is obvious that a proper implementation would be to discard my cashed data when the OSADCOL's table data changes. It seems that I have to use SQLDependency or SQLCacheDependency. The questions are the following:
How am I going to use SQLDependency or SQLCacheDependency with this Repository?
What is the actual difference between these 2?
It is mentioned in some forums that SQLDependency creates memory leaks? Is that true? And If yes is there an alternative approach?
Any Ideas?
With the code below I am having an issue where not all the columns are return data in the data.results array. For example if col4 is null in the database for row 1 then data.results[0] does not contain an element for col4, but row 2 has a value then data.results[1] will contain the value for col4. I would like each return item in the array to contain all items with the database value or null. If null can't be returned then an empty string would do.
var query = new breeze.EntityQuery()
.from('mytable')
.where('col1', 'substringof', '2')
.select('col1,col2,col3,col4')
.orderBy('col1')
.take(200);
return _manager
.executeQuery(query)
.then(function (data) {
return data.results;
})
.fail(queryFailed);
}
By default breeze does not serialize null values in its JSON results. This was a deliberate choice to reduce the breeze payload over the wire. And.. this is not typically an issue with queries that return "entities". i.e. data for which breeze metadata exists. Because the properties are already defined on such entities.
But if you are returning an anonymous result as you are, then this can be a problem. You can obviously work around it because you know the properties that you are requesting and can update them after the query if they are not in the result.
But you can also change breeze's default configuration to accommodate this via the "BreezeConfig" class.
BreezeConfig enables customization of components supporting Breeze-related operations in the Web API. BreezeConfig defines default behaviors; you can substitute your own behaviors by deriving from it and overriding its virtual methods. Breeze.NET will discover your subclass among the assemblies referenced by your project and use it instead of BreezeConfig.
To use BreezeConfig to configure the Json.Net serializer with specific settings. You can replace those settings by writing a subclass of BreezeConfig that overrides the 'CreateJsonSerializerSettings' method as shown in this example:
public class CustomBreezeConfig : Breeze.WebApi.BreezeConfig {
protected override JsonSerializerSettings CreateJsonSerializerSettings() {
var baseSettings = base.CreateJsonSerializerSettings();
baseSettings.NullValueHandling = NullValueHandling.Include;
return baseSettings;
}
Hope this helps.
My problem is hydrating a Viewmodel from a Linq2Sql object that has been returned from the database. We have done this in a few areas and have a nice layered pattern worked up for it but the latest item calls for some enums to be used and this has caused headaches all round. Currently we pull back from the database then use Automapper to hydrate (or flatten) into our Viewmodels but having the enums in the model seems to be causing issues with Automapper. I've tried to create custom resovlers which have sufficed for all my other mapping requirements but it doesn't work in this instance.
A sample of the code looks like:
public class CustomerBillingTabView{
public string PaymentMethod {get; set;}
...other details
}
public class BillingViewModel{
public PaymentMethodType PaymentMethod {get; set;}
...other details
}
public enum PaymentMethodType {
Invoice, DirectDebit, CreditCard, Other
}
public class PaymentMethodTypeResolver : ValueResolver<CustomerBillingTabView, PaymentMethodType>
{
protected override PaymentMethodType ResolveCore(CustomerBillingTabView source)
{
if (string.IsNullOrWhiteSpace(source.PaymentMethod))
{
source.PaymentMethod = source.PaymentMethod.Replace(" ", "");
return (PaymentMethodType)Enum.Parse(typeof(PaymentMethodType), source.PaymentMethod, true);
}
return PaymentMethodType.Other;
}
}
CreateMap<CustomerBillingTabView, CustomerBillingViewModel>()
.ForMember(c => c.CollectionMethod, opt => opt.ResolveUsing<PaymentMethodTypeResolver>())
I get the following error
[ArgumentException: Type provided must be an Enum.
Parameter name: enumType]
System.Enum.TryParseEnum(Type enumType, String value, Boolean ignoreCase, EnumResult& parseResult) +9626766
System.Enum.Parse(Type enumType, String value, Boolean ignoreCase) +80
AutoMapper.Mappers.EnumMapper.Map(ResolutionContext context, IMappingEngineRunner mapper) +231
AutoMapper.MappingEngine.AutoMapper.IMappingEngineRunner.Map(ResolutionContext context) +720
I'd like to stick with Automapper for all of our mapping actions but I've seen a lot of people say that it doesn't do this type of mappings so I'm starting to wonder if I'm using it in the wrong way? Also, I've seen a few mentions of ValueInjecter - is this an alternative to Automapper, or will it be useful to just plug the holes in Automapper for the hydration of models and use Automapper for flattening?
Yes I could just use a string in my ViewModel, but I'm not a fan of magic strings, and this particular item is used by helpers to perform some logic in a number of places.
This is an issue with the AutoMapper documentation. If you download the AutoMapper source there are examples in there. The code you want will look like this:
public class PaymentMethodTypeResolver : ValueResolver<CustomerBillingTabView, PaymentMethodType>
{
protected override PaymentMethodType ResolveCore(CustomerBillingTabView source)
{
string paymentMethod = source.Context.SourceValue as string;
if (string.IsNullOrWhiteSpace(paymentMethod))
{
paymentMethod = paymentMethod.Replace(" ", "");
return source.New((PaymentMethodType)Enum.Parse(typeof(PaymentMethodType), paymentMethod, true));
}
return source.New(PaymentMethodType.Other);
}
}
here's a solution with the ValueInjecter:
since you already solved the problem I'm just going to point you to something similar:
AutoMapper strings to enum descriptions
in this question the requirements were a bit more than just doing from string to enum, but it includes this conversion also
about the ValueInjecter being an alternative: yes, it does stuff more generic no configuration for every little thing required, and build whatever convention you can imagine
In my Custom ObjectContext class I have my entity collections exposed as IObjectSet so they can be unit-tested. I have run into a problem when I use this ObjectContext in a compiled query and call the "Include" extension method (From Julie Lerman's blog http://thedatafarm.com/blog/data-access/agile-entity-framework-4-repository-part-5-iobjectset/):
public IQueryable<MyPocoObject> RunQuery(MyCustomContext context, int theId)
{
var query = CompiledQuery.Compile<MyCustomContext, int, IQueryable<MyPocoObject>>(
(ctx, id) => ctx.MyPocoObjects.Include("IncludedPocoObject").Where(n => n.IncludedPocoObject.id == id));
return query(context, theId);
}
LINQ to Entities does not recognize the method 'System.Linq.IQueryable1[MyPocoObject] Include[MyIncludedPocoObject](System.Linq.IQueryable1[MyPocoObject], System.String)' method, and this method cannot be translated into a store expression.
If I use this same query on ObjectSet collections rather than IObjectSet it works fine. If I simply run this query without precompiling it works fine. What am I missing here?
I'm sure I've just misunderstood as you seem to have been looking at this for a while - But shouldn't you be including the ObjectSet not the object that is queried BY that object set.
eg:
var query = CompiledQuery.Compile<MyCustomContext, int, IQueryable<MyPocoObject>>(
(ctx, id) => ctx.MyPocoObjects
.Include("IncludedPocoObjectSET")
.Where(n => n.IncludedPocoObject.id == id));
Can you also confirm that running the same query without compiling doesn't throw the "can't translate" exception?