Including values from external table in a LINQ statement

Question

I want to write LINQ query for following SQL query:

    SELECT A.ID
    FROM TABLE_1 A, TABLE_2 B
    WHERE A.ID = B.ID
    AND B.STATEID IN (SELECT C.STATEID FROM STATE C WHERE C.REGIONID = 1)

For this I've managed to make following query:

    var var1 = (from a in db.table_1
                join b in db.table_2
                on a.Id equals b.Id
                where b.stateid = 
                select new
                {
                   a.Id
                }).ToList();)

Here how can I include all the StateIDs where RegionId is 1 to get the necessary output.

Answer 1

Your equivalent Linq query would be something:

var result = (from a in db.table_1
              from b in db.table_2 
               where a.Id == b.Id
               && db.State.Any(c=>c.REGIONID  == 1 && b.StateId == c.StateId) 
                select new
                {
                   a.Id
                }).ToList();

Answer 2

You can use Any :-

where db.States.Any(x => x.RegionId == 1 &&  x.StateId == b.StateId)
select...

Answer 3

You can try this..

var var1 = (from a in db.table_1
            join b in db.table_2
            on a.Id equals b.Id
            where db.State.Any(c=> c.RegionId == 1 && c.StateId == b.StateId)
            select new
            {
               a.Id
            }).ToList();)

Answer 4

Try this,

var var1 = (from a in db.table_1
                join b in db.table_2
                on a.Id equals b.Id
                where (db.State.Where(x => x.RegionId == 1).Select(x => 
                       x.StateId)).Contains(b.Id)
                select new
                {
                   a.Id
                }).ToList();)