如何解决如何编写带有计数和左联接的LINQ查询?
我有此代码:
// For typings
import Quill from "react-quill";
import QuillEditor from "quill"
export const MultiLangQuill = ({ content,onChange,lang }) => {
const ref = React.useRef<Quill & { editor: QuillEditor }>(null);
React.useEffect(() => {
ref.current?.editor.root.setAttribute("lang",lang);
},[lang]);
return (
<Quill
// set the ref to access to quill editor
ref={ref}
theme="snow"
value={content}
onChange={onChange}
modules={modules}
formats={formats}
/>
);
};
以前我有这个查询,但是现在我想使用LINQ:
public class DeckOccurrences
{
public string DeckGuid { get; set; }
public int Count { get; set; }
}
public class Deck
{
public string DeckGuid { get; set; }
public string Name { get; set; }
}
public class DeckSource
{
public string DeckGuid { get; set; }
public string Name { get; set; }
}
var decks = App.EF.Db2.Deck.ToList();
var decksources = App.EF.Db2.DeckSource.ToList();
有人可以通过给我一些建议来帮助我吗?
更新显示使用的代码:
select d.deckguid,count(de.deckguid) as Count
from decksource d
left join deck de on d.deckguid = de.deckguid group by d.deckguid
解决方法
就像在Google上首次实现SO搜索
from p in context.ParentTable
join c in context.ChildTable on p.ParentId equals c.ChildParentId into j1
from j2 in j1.DefaultIfEmpty()
group j2 by p.ParentId into grouped
select new { ParentId = grouped.Key,Count = grouped.Count(t=>t.ChildId != null) }
像这样
from d in decksource
join de in deck on d.deckguid equals de.ChildParentId into j1
from j2 in j1.DefaultIfEmpty()
group j2 by d.deckguid into grouped
select new {
deckguid = grouped.Key,Count = grouped.Count(t=>t.deckguid != null)
}
soo
var res = (from d in App.EF.Db2.Decksource
join de in App.EF.Db2.Deck on d.deckguid equals de.ChildParentId into j1
from j2 in j1.DefaultIfEmpty()
group j2 by d.deckguid into grouped
select new {
deckguid = grouped.Key,Count = grouped.Count(t=>t.deckguid != null)
}).ToList()
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