Question

我目前有两个查询，它们共享相同的复杂查询，我只想执行一次：

//Query 1
from together in (...) // ... = Complex query with multiple joins
where together.property == 0
select new { ... }

//Query 2
from together in (...) // ... = Complex query with multiple joins
where together.property > 0
select new { ... }

问题是，他们有一个不同的where子句。我试图在select语句中设置where子句，但这似乎是可能的，如果我使用groupby这里我不需要：

//Don't work
from together in (...) // ... = Complex query with multiple joins
select new {
    //if together would be grouped, this would work. However I need all data without grouping
    //            . Together is not IQueryable so this does not work
    Foo = together.Where(e => e.property == 0).Select(...),
    Bar = together.Where(e => e.property > 0).Select(...)
}

是否可以使用LINQ在一个查询中根据不同的where子句获取2个对象？

Answer 1

您可以查询所有内容，然后将其拆分，就像这样

var qry= (
    from together in (...) // ... = Complex query with multiple joins
    where together.property => 0
    select together)
    .ToList();

var result = new {
    Foo = qry.Where(e => e.property == 0).Select(...),
    Bar = qry.Where(e => e.property > 0).Select(...)
};

在每个对象的不同where子句的一个查询中选择多个对象

1 个答案: