Odtnhj

I'm currently using AutoMapper with explicitly mapped fields and also a possibility for paging combined with LINQ to Entities. My code-part of interest is the following:

 var result = page.ApplyPaging(query)
 .AsQueryable()
 .Project()
 .To<TDto>(null, membersToMap)
 .ToList();

And the paging is done via:

 public IEnumerable<T> ApplyPaging<T>(IEnumerable<T> source)
 
 if (!PagingEnabled)
 
 return source;
 

 var skippedEntries = (PageNumber.GetValueOrDefault(1) - 1) * PageSize;
 var result = source.Skip(skippedEntries).Take(PageSize);

 return result;
 

What's interesting now: With this implementation, the membersToMap Array is ignored and AutoMapper joins ALL navigation tables, busting a huge SQL query. What I don't understand: If I change the Paging to:

 public IQueryable<T> ApplyPaging2<T>(IQueryable<T> source)
 
 if (!PagingEnabled)
 
 return source;
 

 var skippedEntries = (PageNumber.GetValueOrDefault(1) - 1) * PageSize;
 var result = source.Skip(skippedEntries).Take(PageSize);

 return result;
 

And remove the .AsQueryable, AutoMapper does fetch just the Tables needed. Probably I'm missing a critical puzzlepiece, but as far as I know, changing the compile-time type via AsQueryable should not change any behavior, if the underlying list is already an IQueryable.
Is this therefore an AutoMapper problem or am I miss-using the possibility to convert from IQueryable to IEnumerable and back?