I am trying to run this code:
ItemTaxonomy iTaxonomy = from itemTaxonomy in connection.ItemTaxonomy
where itemTaxonomy.Item.ID == itemView.ID
orderby itemTaxonomy.Taxonomy.Name
select itemTaxonomy;
When I compiled it I get the error:
Cannot implicitly convert type
'System.Linq.开发者_JS百科IOrderedQueryable<Website.Models.ItemTaxonomy>'
to'Website.Models.ItemTaxonomy'
. An explicit conversion exists (are you missing a cast?)
I believe the issue is with orderby itemTaxonomy.Taxonomy.Name
but I am just trying to order by the name of Taxonomy items instead of their IDs. Is there a way to do that?
No, the problem is that the result is a sequence whereas your variable is a single item.
Given that you're expressing ordering, you must be expecting multiple values - so what do you want to do with them? Options:
Use
First()
:ItemTaxonomy iTaxonomy = (from itemTaxonomy in connection.ItemTaxonomy where itemTaxonomy.Item.ID == itemView.ID orderby itemTaxonomy.Taxonomy.Name select itemTaxonomy).First();
This will return the
ItemTaxonomy
with the earliest name out of all the ones with the appropriate item ID.Change your variable type:
IEnumerable<ItemTaxonomy> taxonomies = from itemTaxonomy in connection.ItemTaxonomy where itemTaxonomy.Item.ID == itemView.ID orderby itemTaxonomy.Taxonomy.Name select itemTaxonomy;
Now you've got a sequence of taxonomies to deal with, instead of a single item.
You seem to be capturing a single value from a query. Try:
var iTaxonomy = from itemTaxonomy in connection.ItemTaxonomy
where itemTaxonomy.Item.ID == itemView.ID
orderby itemTaxonomy.Taxonomy.Name
select itemTaxonomy;
or to be more explicit:
IQueryable<ItemTaxonomy> iTaxonomy = ...
If you do want a single item, use ,First()
or .Single()
.
The LINQ query returns a set (IEnumerable<T>
) of ItemTaxonomy
objects, which you are trying to assign to a variable of type ItemTaxonomy
.
You need to change the type of the variable to IEnumerable<ItemTaxonomy>
. (Or call First()
)
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