How do I return a table in LINQ that relies on a join/subquery?

I need the fields in 1 table contingent on 1 pro开发者_C百科perty matching rows in another table. I can write this query in SQL with a subquery as such:

SELECT *
FROM Table1
WHERE Property1 IN
(
    SELECT Property1
    FROM Table2
    WHERE Property0 = 1
)

But I read here that it's less complicated and just as easy to write with a join, which I did. However, so far I'm unable to return just Table1 as I'd like since I'm using a join, which if I'm not mistaken, requires me to create this anonymous type, as below. What I did here works (I created another object with the same properties of Table1 I need), but I can't help thinking there's a better way to do this.

Table1.Join(Table2, t1 => t1.Property1, t2 => t2.Property1, (t1, t2) => new
{
    t1.Property1,
    t1.Property2,
    t1.Property3
})
.Select(ob => new UnnecessaryObject
{
    Property1 = ob.Property1,
    Property2 = ob.Property2,
    Property3 = ob.Property3
}

I also tried just creating a Table1 in the .Select part, but I got an error about explicit construction not being allowed.

Just to clarify, I'd like to be able to return the IQueryable of type Table1, which it seems like I ought to be able to do without having to create UnnecessaryObject...but I'm still pretty new to LINQ, so I'd appreciate any help you can offer. Thanks in advance.

You could just do:

from t1 in table1
join t2 in table2 on t1.property1 equals t2.property1
select t1;

That would return a collection of table1 objects. This assumes from your example table1 is a collection of table1 objects and table2 is a collection of table2 objects.

The best translation of your original query I can come up with is:

from item in context.Table1
where context.Table2
    .Where(x => x.Property0 == 0)
    .Any(x => x.Property1 == item.Property1)
select item

This selects all items from Table1, where there's an item with matching Property1 and Property0 == 0 from Table2

It can also be solved with a join indeed. To get an efficient join, you need to have a relation between the two tables. Then you can do something like assuming the relation is called RelatedItems:

from item in context.Table1
join relatedItem in item.RelatedItems
    on item.Property1 equals relatedItem.Property
where relatedItem.Property0 == 0

select item

This is equivalent to the SQL:

SELECT * 
FROM Table1
JOIN Table2 ON Table1.Property1 = Table2.Property1
WHERE Table2.Property0 = 0