這可能看起來很複雜,但我實際上只是試圖從A中選擇所有記錄及其子項,其中子項中存在特定條件。尋找語法,我可以添加到一個變量,讓我來過濾一堆條件Linq:在嵌套模型上執行Where()子句
如果你有這樣一個嵌套的視圖(如規範模式):
var a = from Arow in Atable
where ???
select new AViewModel { // (image Products)
id = Arow.id,
name = Arow.Name,
Brows = (from Brow in Arow.Brows
select new BViewModel { // (sold in different regions)
id = Brow.id,
name = Brow.Name,
Crows = (from Crow in Brow.Crows
select new CViewModel { // (and in many stores)
id = Crow.id,
name = Crow.Name
}
}
};
和文字較從網頁上查詢,像這樣的(規範模式?) 我們使用jQuery選擇的運營商
filter[] = { "Brow.Name = Joe", "Crow.Name = Kim" }
你怎麼能過濾用這些標準的表達A(像^ =表示「開頭」)?換句話說,你可以有一個where表達式,像a.Where()可以過濾嵌套屬性?
我可憐的嘗試:
var b = from row in a
where a.Brow.Where(b => b.name == "Joe") &&
a.Brow.Crow.Where(c => c.name == "Kim")
select row;
我真正需要的是這樣的:
Select *
from A join B on A.key = B.key join C on B.key = C.key -- propagated keys
where exists (select null from B where A.key = B.key and B.Name = "Joe") and
exists (select null from C where A.key = C.key and C.Name = "Kim")
特別是,如果我能做到這一點:
var result = a.Where(first).Where(second);
這幾乎是正確的,還是我做錯了什麼。 a.Brow.Any()可以工作,但使用a.Brow.Crow到達Crow會失敗。然而,a.Brow.Any(p => p.Crow.Any(c => c.name ==「Kim」))看起來很有希望。 – 2010-11-04 21:25:07