I have this rather complex query in SQL server 2008:
declare #LanguageID as int = 1
select k.datePublish, k.dateEditing, k.dateTables
from TableAreasLevel1 as areaL1
inner join TableAreasLevel2 as areaL2
on areaL1.LanguageID = areaL2.LanguageID and
areaL1.CodeAreaLevel1 = areaL2.CodeAreaLevel1
inner join TableAreasLink as link
on areaL2.CodeAreaLevel1 = link.CodeAreaLevel1 and
areaL2.CodeAreaLevel2 = link.CodeAreaLevel2 and
inner join TableProducts as tblProds
on tblProds.CodeAreaLevel1 = areaL1.CodeAreaLevel1 and
tblProds.CodeAreaLevel2 = areaL2.CodeAreaLevel2
inner join TableSI_Products as prod
on prod.SiAreaCode = link.SiAreaCode
inner join TableCalendar as k
on k.KodTableSI_Products = tblProds.KodTableSI_Products
where areaL1.LanguageID = #LanguageID and
prod.Code = 'some string' and
k.LanguageID = #LanguageID and
tblProds.LanguageID = #LanguageID;
I am trying to develop the same query in LINQ, but I get error when I try join the table TableProducts, i.e the third consecutive join.
Here is my LINQ query:
List<Tuple<DateTime, DateTime, DateTime>> dates = (from areaL1 in gpe.TableAreasLevel1
join areaL2 in gpe.TableAreasLevel2
on new { areaL1.CodeAreaLevel1, areaL1.LanguageID } equals
new { areaL2.CodeAreaLevel1, areaL2.LanguageID }
join link in gpe.TableAreasLink
on new { areaL2.CodeAreaLevel1, areaL2.CodeAreaLevel2, areaL2.RbrOblastNivo2} equals
new {link.CodeAreaLevel1, link.CodeAreaLevel2}
join tblProds in gpe.TableProducts
on tblProds. // The name tblProds is not in the scope of the left side of 'equals'
);
Is the problem connected with how the tables are designed or, something else I should check for?
Any ideas, why tblProds is not visible in the scope of the LINQ query?
You are using Query as your guide something like:
on k.KodTableSI_Products = tblProds.KodTableSI_Products
but take a look at your linq:
on new { areaL1.CodeAreaLevel1, areaL1.LanguageID } equals
it has two fields. I think its not a good idea.
linq join something like
var dates = (from areaL1 in gpe.TableAreasLevel1
join areaL2 in gpe.TableAreasLevel2
on areaL1.PKFields equals areaL2.PKFields
where areaL1.CodeAreaLevel1== areaL2.CodeAreaLevel1 && areaL1.LanguageID = areaL2.LanguageID
Select new YournewClass{YournewClass.Field1=areaL1.fields1, And so on}
)
You can do to join the other tables with aliases.
Sorry need to go for now.
I'm giving you an idea.
Hope it helps.
I have a problem. I get all data in var type variable and then want to apply a join with database table in code first approach. Facing problem, lot of search on internet and apply but failed.
var joinedData =
from menuGroup in _menuGroupMenusRepository.GetAll()
.Where(x => x.GroupId == input.GroupId)
join menus in _menuRepository.GetAll()
on menuGroup.MenuId equals menus.Id
join categSubcateg in _menuCategSubCategRepository.GetAll()
on menus.Id equals categSubcateg.MenuId
join categ in _menuCategoryRepository.GetAll()
on categSubcateg.CategoryId equals categ.Id
select new
{
CategoryId = categSubcateg.CategoryId,
CategoryName = categ.Category,
};
Now I want joinedData variable join with MainMenuSort table.
MainMenuSort table also have groupid and categoryid.
to perform join you just need to do as below
var q=(from jd in joinedData
join mms in dataContext.MainMenuSort
on jd.CategoryId equals mms.CategoryId
select jd).ToList();
if its datatable then
var q=(from jd in joinedData
join mms in dtMainMenuSort.AsEnumerable()
on jd.CategoryId equals mms.Field<int>("CategoryId")
select jd).ToList();
I'm writing a LINQ to SQL statement, and I'm after the standard syntax for a normal inner join with an ON clause in C#.
How do you represent the following in LINQ to SQL:
select DealerContact.*
from Dealer
inner join DealerContact on Dealer.DealerID = DealerContact.DealerID
It goes something like:
from t1 in db.Table1
join t2 in db.Table2 on t1.field equals t2.field
select new { t1.field2, t2.field3}
It would be nice to have sensible names and fields for your tables for a better example. :)
Update
I think for your query this might be more appropriate:
var dealercontacts = from contact in DealerContact
join dealer in Dealer on contact.DealerId equals dealer.ID
select contact;
Since you are looking for the contacts, not the dealers.
And because I prefer the expression chain syntax, here is how you do it with that:
var dealerContracts = DealerContact.Join(Dealer,
contact => contact.DealerId,
dealer => dealer.DealerId,
(contact, dealer) => contact);
To extend the expression chain syntax answer by Clever Human:
If you wanted to do things (like filter or select) on fields from both tables being joined together -- instead on just one of those two tables -- you could create a new object in the lambda expression of the final parameter to the Join method incorporating both of those tables, for example:
var dealerInfo = DealerContact.Join(Dealer,
dc => dc.DealerId,
d => d.DealerId,
(dc, d) => new { DealerContact = dc, Dealer = d })
.Where(dc_d => dc_d.Dealer.FirstName == "Glenn"
&& dc_d.DealerContact.City == "Chicago")
.Select(dc_d => new {
dc_d.Dealer.DealerID,
dc_d.Dealer.FirstName,
dc_d.Dealer.LastName,
dc_d.DealerContact.City,
dc_d.DealerContact.State });
The interesting part is the lambda expression in line 4 of that example:
(dc, d) => new { DealerContact = dc, Dealer = d }
...where we construct a new anonymous-type object which has as properties the DealerContact and Dealer records, along with all of their fields.
We can then use fields from those records as we filter and select the results, as demonstrated by the remainder of the example, which uses dc_d as a name for the anonymous object we built which has both the DealerContact and Dealer records as its properties.
var results = from c in db.Companies
join cn in db.Countries on c.CountryID equals cn.ID
join ct in db.Cities on c.CityID equals ct.ID
join sect in db.Sectors on c.SectorID equals sect.ID
where (c.CountryID == cn.ID) && (c.CityID == ct.ID) && (c.SectorID == company.SectorID) && (company.SectorID == sect.ID)
select new { country = cn.Name, city = ct.Name, c.ID, c.Name, c.Address1, c.Address2, c.Address3, c.CountryID, c.CityID, c.Region, c.PostCode, c.Telephone, c.Website, c.SectorID, Status = (ContactStatus)c.StatusID, sector = sect.Name };
return results.ToList();
You create a foreign key, and LINQ-to-SQL creates navigation properties for you. Each Dealer will then have a collection of DealerContacts which you can select, filter, and manipulate.
from contact in dealer.DealerContacts select contact
or
context.Dealers.Select(d => d.DealerContacts)
If you're not using navigation properties, you're missing out one of the main benefits on LINQ-to-SQL - the part that maps the object graph.
Use Linq Join operator:
var q = from d in Dealer
join dc in DealerConact on d.DealerID equals dc.DealerID
select dc;
basically LINQ join operator provides no benefit for SQL. I.e. the following query
var r = from dealer in db.Dealers
from contact in db.DealerContact
where dealer.DealerID == contact.DealerID
select dealerContact;
will result in INNER JOIN in SQL
join is useful for IEnumerable<> because it is more efficient:
from contact in db.DealerContact
clause would be re-executed for every dealer
But for IQueryable<> it is not the case. Also join is less flexible.
Actually, often it is better not to join, in linq that is. When there are navigation properties a very succinct way to write your linq statement is:
from dealer in db.Dealers
from contact in dealer.DealerContacts
select new { whatever you need from dealer or contact }
It translates to a where clause:
SELECT <columns>
FROM Dealer, DealerContact
WHERE Dealer.DealerID = DealerContact.DealerID
Inner join two tables in linq C#
var result = from q1 in table1
join q2 in table2
on q1.Customer_Id equals q2.Customer_Id
select new { q1.Name, q1.Mobile, q2.Purchase, q2.Dates }
Use LINQ joins to perform Inner Join.
var employeeInfo = from emp in db.Employees
join dept in db.Departments
on emp.Eid equals dept.Eid
select new
{
emp.Ename,
dept.Dname,
emp.Elocation
};
Try this :
var data =(from t1 in dataContext.Table1 join
t2 in dataContext.Table2 on
t1.field equals t2.field
orderby t1.Id select t1).ToList();
OperationDataContext odDataContext = new OperationDataContext();
var studentInfo = from student in odDataContext.STUDENTs
join course in odDataContext.COURSEs
on student.course_id equals course.course_id
select new { student.student_name, student.student_city, course.course_name, course.course_desc };
Where student and course tables have primary key and foreign key relationship
try instead this,
var dealer = from d in Dealer
join dc in DealerContact on d.DealerID equals dc.DealerID
select d;
var Data= (from dealer in Dealer join dealercontact in DealerContact on dealer.ID equals dealercontact.DealerID
select new{
dealer.Id,
dealercontact.ContactName
}).ToList();
var data=(from t in db.your tableName(t1)
join s in db.yourothertablename(t2) on t1.fieldname equals t2.feldname
(where condtion)).tolist();
var list = (from u in db.Users join c in db.Customers on u.CustomerId equals c.CustomerId where u.Username == username
select new {u.UserId, u.CustomerId, u.ClientId, u.RoleId, u.Username, u.Email, u.Password, u.Salt, u.Hint1, u.Hint2, u.Hint3, u.Locked, u.Active,c.ProfilePic}).First();
Write table names you want, and initialize the select to get the result of fields.
from d1 in DealerContrac join d2 in DealerContrac on d1.dealearid equals d2.dealerid select new {dealercontract.*}
One Best example
Table Names : TBL_Emp and TBL_Dep
var result = from emp in TBL_Emp join dep in TBL_Dep on emp.id=dep.id
select new
{
emp.Name;
emp.Address
dep.Department_Name
}
foreach(char item in result)
{ // to do}
Please anyone can help me to write this sql query into Linq. i have tried..
this is my sql query
select o.OrderID,o.Nature,o.Date,od.TotalPrice,os.OrderStatus,lo.FirstName,lo.EmailAddress,lo.PhoneNumber
from [dbo].[Order] o
inner join [dbo].[tbl_OrderDetails] od on od.OrderID = o.OrderID
inner join [dbo].[tbl_OrderHistory] oh on oh.OrderID = o.OrderID
inner join [dbo].[tbl_Login] lo on o.UserID = lo.UserID
inner join dbo.tbl_OrderStatus os on oh.OrderStatusID= os.OrderStatusID
group by o.OrderID,o.Nature,od.TotalPrice,o.Date,os.OrderStatus,lo.FirstName,lo.EmailAddress,lo.PhoneNumber
and this is my try
public override orderDetailModel orderDetails(int id)
{
var results = from o in obj.Orders
join od in obj.tbl_OrderDetails on o.OrderID equals od.OrderID
join oh in obj.tbl_OrderHistory on o.OrderID equals oh.OrderID
join l in obj.tbl_Login on o.UserID equals l.UserID
join os in obj.tbl_OrderStatus on oh.OrderStatusID equals os.OrderStatusID
where (od.OrderID == id)
group o by new { o.Nature, o.OrderID } into
select new orderDetailModel
{
OrderID = o.OrderID,
OrderStatus = os.OrderStatus,
Date = o.Date,
DeliveryNature = o.Nature,
EmailAddress = l.EmailAddress,
FirstName = l.FirstName,
PhoneNumber = l.PhoneNumber,
TotalPrice = od.TotalPrice
};
//group o by new {o.OrderID};
orderDetailModel data = (orderDetailModel)results.FirstOrDefault();
return data;
}
but this is wrong query its not working fine please help me
You need to correct the group by clause, like you have in the SQL query like this:-
group new { o, l } by new { o.OrderID,o.Nature,od.TotalPrice,o.Date,os.OrderStatus,
l.FirstName, l.EmailAddress,l.PhoneNumber } into g
select new orderDetailModel
{
OrderID = g.Key.OrderID,
OrderStatus = g.Key.OrderStatus,
Date = g.Key.Date,
..and so on
};
Since you need the grouping on two tables Order & tbl_Login you will have to first project them as anonymous type group new { o, l } then specify all the groupings and finally while projecting use Key to get the respective items.
I guess that actually, also the SQL query is not correct.
I would simply use a SELECT DISTINCT ... instead of Grouping all the columns.
Anyway, first thing to do:
Check if databases is designed correctly. As far as i can see, if you're joining the table with their Ids, i don't understand why you need to group all the data. If you have duplicates, maybe the error is in the Database design.
If you can't change your Database, or you are happy with it, then use the following LINQ approach:
var distinctKeys = allOrderDetails.Select(o => new { o.OrderID, o.Nature, o.TotalPrice, o.Date,o.OrderStatus,o.FirstName, o.EmailAddress,o.PhoneNumber }).Distinct();
var joined = from e in allOrderDetails
join d in distinctKeys
on new { o.OrderID, o.Nature,o.TotalPrice, o.Date,o.OrderStatus, o.FirstName, o.EmailAddress, o.PhoneNumber } equals d select e;
joined.ToList(); // gives you the distinct/grouped list
I have a problem creating the following SQL Statement using LINQ & C#
select c.IDAddenda, c.Descripcion
from CatAddendas c
right join EmpresaAddenda e on e.IDAddenda = c.IDAddenda
where e.rfc = 'SUL010720JN8'
order by c.IDAddenda asc
I got this:
public IEnumerable<CatAddenda> TraeAddendas(string rfc)
{
DataClasses1DataContext dc = new DataClasses1DataContext(...);
return (from adds in dc.EmpresaAddendas
cats.IDAddenda into joined
where adds.RFC == rfc
select adds.CatAddenda);
}
This is not doing a right join, so any ideas?
var RightJoin = from adds in dc.EmpresaAddendas
join cats in CatAddendas
on adds.IDAddenda equals cats.IDAddenda into joined
from cats in joined.DefaultIfEmpty()
select new
{
Id = cats.IDAddenda,
Description = cats.Descripcion
};
var results = from e in EmpresaAddenda
join c in CatAddendas
on e.IDAddenda equals c.IDAddenda into f
from c in f.DefaultIfEmpty()
select new
{
ID = c.IDAddenda,
Description = c.Descripcion
};
You can apply where and order by on the results.