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Linq to sql join with multiple "OR" filters

I need to implement this in Linq-to-sql
SELECT DISTINCT c.*
FROM dbo.Collector_Capital_Equipment c
LEFT OUTER JOIN dbo.Lab_Space s ON c.Room = s.Entry_Bar_Code
OR c.HomeRoom = s.Entry_Bar_Code
WHERE s.id = 1021645
All the research I've done on this says that linq-to-sql can't support an "OR" multiple join, and the suggestions are to instead do two joins like this:
SELECT DISTINCT c.*
FROM dbo.Collector_Capital_Equipment c
LEFT OUTER JOIN dbo.Lab_Space s ON c.Room = s.Entry_Bar_Code
LEFT OUTER JOIN dbo.Lab_Space s2 ON c.HomeRoom = s2.Entry_Bar_Code
WHERE s.id = 1021645
Those aren't actually the same query though as they'll return different results. Short of just putting the raw SQL into my C# program at this point, is there any way to accomplish the above?

Let's start from beginning. If you use WHERE with column from OUTER JOIN table it means that your query:
SELECT DISTINCT c.*
FROM dbo.Collector_Capital_Equipment c
LEFT OUTER JOIN dbo.Lab_Space s ON c.Room = s.Entry_Bar_Code
OR c.HomeRoom = s.Entry_Bar_Code
WHERE s.id = 1021645
is logically equivalent to:
SELECT DISTINCT c.*
FROM dbo.Collector_Capital_Equipment c
JOIN dbo.Lab_Space s
ON c.Room = s.Entry_Bar_Code
OR c.HomeRoom = s.Entry_Bar_Code
WHERE s.id = 1021645;
And this could be achieved with CROSS JOIN(pseudocode):
var q = from c in Collector_Capital_Equipment
from s in Lab_Space
where s.id == 1021645
&& (s.Entry_Bar_Code == c.Room || c.HomeRoom == s.Entry_Bar_Code)
select ...
I assume that you really want to generate query:
SELECT DISTINCT c.*
FROM dbo.Collector_Capital_Equipment c
LEFT OUTER JOIN dbo.Lab_Space s
ON (c.Room = s.Entry_Bar_Code OR c.HomeRoom = s.Entry_Bar_Code)
AND s.id = 1021645
which could be represented as:
SELECT c.*
FROM dbo.Collector_Capital_Equipment c
LEFT OUTER JOIN dbo.Lab_Space s
ON c.Room = s.Entry_Bar_Code AND s.id = 1021645
INTERSECT
SELECT c.*
FROM dbo.Collector_Capital_Equipment c
LEFT OUTER JOIN dbo.Lab_Space s
ON c.HomeRoom = s.Entry_Bar_Code AND s.id = 1021645
And above query could be achieved with LINQ using set operators.
db<>fiddle demo

I don't think I've ever seen someone use an OR clause on a join before. Does MS SQL Server even support that in SQL?
I'd probably just split this off into two queries, to be honest.
SELECT entry_bar_code
FROM dbo.Lab_Space WHERE id = 1021645;
With the result from that being fed into
SELECT DISTINCT *
FROM dbo.Collector_Capital_Equipment
WHERE c.room == <barcode> OR c.homeRoom == <barcode>

Select IN LINQ to entities with inner joins

I have the follow SQL query
SELECT ob.PK_OBJETIVO,
ev.NM_EVENTO,
ifi.QT_NOTA_IMPACTO,
imi.QT_NOTA_IMPACTO,
ire.QT_NOTA_IMPACTO,
(ifi.QT_NOTA_IMPACTO + imi.QT_NOTA_IMPACTO + ire.QT_NOTA_IMPACTO)/3 AS
Media
FROM AVALIACAO_IMPACTO AS ai
INNER JOIN EVENTO AS EV ON ev.PK_EVENTO = ai.FK_AVALIACAO_IMPACTO_EVENTO
INNER JOIN OBJETIVO AS ob ON ob.PK_OBJETIVO =
ai.FK_AVALIACAO_IMPACTO_OBJETIVO
INNER JOIN IMPACTO_FINANCEIRO AS ifi ON ifi.PK_IMPACTO_FINANCEIRO =
ai.FK_AVALIACAO_IMPACTO_IMPACTO1
INNER JOIN IMPACTO_MISSAO AS imi ON IMI.PK_IMPACTO_MISSAO =
AI.FK_AVALIACAO_IMPACTO_IMPACTO2
INNER JOIN IMPACTO_REPUTACAO AS IRE ON IRE.PK_IMPACTO_REPUTACAO =
AI.FK_AVALIACAO_IMPACTO_IMPACTO3
WHERE ai.FK_AVALIACAO_IMPACTO_OBJETIVO IN
(SELECT OBJ.PK_OBJETIVO
FROM OBJETIVO AS OBJ
WHERE OBJ.FK_OBJETIVO_PROCESSO = 3)
I need to transform that query in a LINQ query, I tried that:
var queryImpactos = await _context.AvaliacaoImpacto
.Where(e => _context.Objetivo.Select(o =>
o.ProcessoID).Contains(planoRiscos.Auditoria.ProcessoID))
.Include(e => e.Evento).Include(e => e.Objetivo)
.Include(e => e.ImpactoFinanceiro).Include(e =>
e.ImpactoMissao).Include(e => e.ImpactoReputacao).ToListAsync();
"planoRiscos.Auditoria.ProcessoID" returns what it takes, the number 3 of the pure SQL query, but the query result is returning all the records in the AVALIACAO_IMPACTO table, however I only need the records where a FK_OBJETIVO in AVALIACAO_IMPACTO exists within the OBJETIVO table, where the FK_PROCESSO in OBJETIVO is equal to the passed parameter (planoRiscos.Auditoria.ProcessoID).

Tip: whenever you need to convert SQL query to a LINQ query, make the query syntax your first choice.
Try this:
var queryImpactos = from ai in AVALIACAO_IMPACTO
join
ev in EVENTO on ai.FK_AVALIACAO_IMPACTO_EVENTO equals ev.PK_EVENTO
join ob in OBJETIVO on ai.FK_AVALIACAO_IMPACTO_OBJETIVO equals ob.PK_OBJETIVO
join ifi in IMPACTO_FINANCEIRO on ai.FK_AVALIACAO_IMPACTO_IMPACTO1 equals ifi.PK_IMPACTO_FINANCEIRO
join imi in IMPACTO_MISSAO on ai.FK_AVALIACAO_IMPACTO_IMPACTO2 equals imi.PK_IMPACTO_MISSAO
join IRE in IMPACTO_REPUTACAO on ai.FK_AVALIACAO_IMPACTO_IMPACTO3 equals IRE.PK_IMPACTO_REPUTACAO
where (from obj in OBJETIVO where obj.FK_OBJETIVO_PROCESSO == 3 select obj.PK_OBJETIVO).Contains(ai.FK_AVALIACAO_IMPACTO_OBJETIVO)
select new
{
ob.PK_OBJETIVO,
ev.NM_EVENTO,
QT_NOTA_IMPACTO1 = ifi.QT_NOTA_IMPACTO,
QT_NOTA_IMPACTO2 = imi.QT_NOTA_IMPACTO,
QT_NOTA_IMPACTO3 = IRE.QT_NOTA_IMPACTO,
Media = (ifi.QT_NOTA_IMPACTO + imi.QT_NOTA_IMPACTO + IRE.QT_NOTA_IMPACTO) / 3
};
Hope it's what you're looking for!

convert SQL to LINQ not working

I want to convert this SQL code to LINQ. Here is my SQL code:
SELECT Rooms.RoomName AS RoomNo, Beds.BedName AS Beds, Rooms.RoomType, ISNULL(CheckIn.CheckIntatus,'') AS Status
FROM CheckIn
INNER JOIN GuestBeds ON CheckIn.GuestBedId = GuestBeds.Id
AND (CheckIn.CheckInStatus = 1 OR CheckIn.CheckIntatus = 2 OR CheckIn.CheckSIntatus = 3)
RIGHT JOIN Beds ON GuestBeds.BedId = Beds.Id
INNER JOIN Rooms ON Beds.RoomId = Rooms.Id
LEFT JOIN Guests ON CheckIn.GuestId = Guests.Id
WHERE Beds.Active = 1 AND Rooms.Active = 1
ORDER BY RoomName, Beds
It works well which means it shows all the RoomName with CheckInStatus. If the Room is not presence in CheckIn table, ot will return the status as Null.
So I want to convert the code to LINQ. SO here is my LINQ code:
from b in Beds
join w in Rooms on b.RoomsId equals w.Id
where (a.CheckInStatus == 3 || a.CheckInStatus == 1 || a.CheckInStatus == 2)
join p in GuestBeds on b.Id equals p.BedId
join a in CheckIn on p.Id equals a.GuestBedId
join t in Guests on a.GuestId equals t.Id
where b.Active == true && w.Active == true
orderby w.RoomName
select new
{
RoomName = w.RoomName,
BedName = b.BedName,
Status = a.CheckInStatus
}
It didnt worked like the first code. It only show the data which contain CheckInStatus. I want it to show all the RoomName inside Room database

Normally I would post some rules for converting SQL to LINQ but this is complicated enough I think I'd need to make new rules. I commented out the references to Guests because as a LEFT JOIN it has no bearing on the answer.
Pull out the WHERE on individual tables and make them sub-queries:
var ActiveBeds = Beds.Where(b => b.Active == 1);
var ActiveRooms = Rooms.Where(r => r.Active == 1);
In LINQ, a RIGHT JOIN must be done by flipping the join to be a left join, so we will create the two sides as sub-queries.
Left side of RIGHT JOIN:
Translate the JOIN conditions that aren't part of an equi-join into a LINQ where clause on the appropriate tables (alternately this could be a subquery as above). The LEFT JOIN becomes a LINQ join/from ... DefaultIfEmpty() phrase, but as noted above isn't needed.
var CheckInsGuestBedsGuests = from c in CheckIn
where (c.CheckInStatus == 1 || c.CheckInStatus == 2 || c.CheckInStatus == 3)
join gb in GuestBeds on c.GuestBedId equals gb.Id
//join g in Guests on c.GuestId equals g.Id into gj
//from g in gj.DefaultIfEmpty()
select new { c, gb /*, g */ };
Right side of RIGHT JOIN:
The other side of the RIGHT JOIN includes an INNER JOIN so put them together in a sub-query:
var ActiveBedsRooms = from b in ActiveBeds
join r in ActiveRooms on b.RoomId equals r.Id
select new { b, r };
Finally, flip the sub-queries to create a left join using the same idiom as above:
var ans = from br in ActiveBedsRooms
join cgbg in CheckInsGuestBedsGuests on br.b.Id equals cgbg.gb.BedId into cgbgj
from cgbg in cgbgj.DefaultIfEmpty()
select new {
RoomNo = br.r.RoomName,
Beds = br.b.BedName,
br.r.RoomType,
Status = cgbg.c.CheckInStatus
};
NOTE: If you were not using LINQ to SQL, the Status expression would fail when cgbg is null and you would need
Status = cgbg?.c.CheckInStatus
but unfortunately LINQ to SQL/EF doesn't handle the null conditional operators yet.
BTW, nice query - brings back memories of when I used to write hotel front desk software :)

LINQ Left Join with multiple ON OR conditions

I'm sorry for telling that I've a little bit weak on LINQ, I always do write SQL query before I start working on the complicated LINQ.
I want to ask that how to convert this SQL Query into LINQ with LEFT JOIN with multiple ON conditons with the OR operator.,
m.MerchandiseId will be use for twice in ON condition
SELECT
*
FROM
Inbox AS i
INNER JOIN [User] AS u ON i.FromUserId = u.UserId
LEFT OUTER JOIN Merchandise AS m ON
u.MerchandiseId = m.MerchandiseId
OR
i.ToMerchantId = m.MerchandiseId
WHERE
i.ToCompanyId = 10
OR
i.FromCompanyId = 10
var message = (from i in db.Inbox
join u in db.User on i.FromUserId equals u.UserId
join m in db.Merchandise on u.MerchandiseId equals m.MerchandiseId //here I want to ON i.MerchantId = m.MerchandiseId, but it doesn't allow
where i.ToCompanyId == user.CompanyId || i.FromCompanyId == user.CompanyId
orderby i.CreatedAt descending
group m.MerchandiseId by new { m.MerchandiseId, m.MerchandiseName } into grp
select new
{
MerchandiseId = grp.Key.MerchandiseId,
MerchandiseName = grp.Key.MerchandiseName,
InboxMessage = (from e in db.Inbox
join us in db.User on e.FromUserId equals us.UserId
join mer in db.Merchandise on us.MerchandiseId equals mer.MerchandiseId
where mer.MerchandiseId == grp.Key.MerchandiseId
orderby e.CreatedAt descending
select e.InboxMessage).FirstOrDefault(),
CreatedAt = (from e in db.Inbox
join us in db.User on e.FromUserId equals us.UserId
join mer in db.Merchandise on us.MerchandiseId equals mer.MerchandiseId
where mer.MerchandiseId == grp.Key.MerchandiseId
orderby e.CreatedAt descending
select e.CreatedAt).FirstOrDefault(),
}).ToList();
The bottom LINQ Query I've write for it. However, I just can work on the left join with multiple ON clause in LINQ. Appreciate if someone would help me on this. Thanks!

I don't believe Linq supports the use of the OR operator with multiple columns, but that said, I wouldn't use OR even in SQL as it makes the join's intention unclear and it also obscures where the data originated from - it also isn't immediately clear what happens if there are multiple matches for each column. Instead I would JOIN twice on the different columns and let the projection-clause handle it:
SELECT
*
FROM
Inbox
INNER JOIN [User] AS u ON i.FromUserId = u.UserId
LEFT OUTER JOIN Merchandise AS userMerchant ON u.MerchandiseId = userMerchant.MerchandiseId
LEFT OUTER JOIN Merchandise AS inboxMerchant ON Inbox.ToMerchantId = inboxMerchant .MerchandizeId
WHERE
Inbox.ToCompanyId = 10
OR
Inbox.FromCompanyId = 10
This can then be translated into Linq using the LEFT OUTER JOIN approach ( How to implement left join in JOIN Extension method )
Note that if you're using Entity Framework then you don't need to worry about doing any of this at all! Just use Include:
var query = db.Inbox
.Include( i => i.User )
.Include( i => i.User.Merchandise )
.Include i => i.Merchandise )
.Where( i => i.ToCompanyId = 10 || i.FromCompanyId == 10 );

Convert SQL Left Join to Linq Expression Left Join

I have a query from SQL and I'm doing a left join. It's working ok.
SELECT Table1.Id, Table1.Comments, Table1.IdListDef
FROM Table2 INNER JOIN Table1 ON Table2.Id = Table1.IdListDef
LEFT JOIN Table3
ON Table1.Id = Table3.IdComments
WHERE Table1.IdListDef = 36 and Table2.IdRev = 1075 and Table3.IdAutor IS NULL
I need to transfrom this query to Linq Expression from C#. How can I do it? I don't know how to transform this query that contains left join.

It should look something like this:
var result = (
from item1 in table1
join item2 in table2 on item1.IdListDef equals item2.Id
join item3 in table3 on item1.Id equals item3.IdComments into finalGroup
from finalItem in finalGroup.DefaultIfEmpty()
where item1.IdListDef == 36 && item2.IdRev == 1075 && finalItem.IdAutor == null
select new
{
item1.Id, item1.Comments, item1.IdListDef
}).ToList();
Addition to your comment, if you're willing to see if any item has id of your outer parameter you could use linq Any extension method:
bool idExists = result.Any(item => item.id == idAutor);

TRY THIS QUERY
VAR OBJLIST=(FROM A IN CONTEX.TABLE2
FROM B IN CONTEX.TABLE1.WHERE(X=>X.IdListDef==a.Id && B.IdListDef==36 && B.IdRev==1075 )
FROM C IN CONTEX.TABLE3.WHRE(X=>X.IdComments==a.Id).DefaultEmpty()
where C.IdAutor==NULL
select new{a.Id, a.Comments, a.IdListDef }).ToList()