select in Join experssion

radouane zili

how to select all the columns from both query ( Join case) , see the example below :

var particiapants = from p in data.getAllParticipant() from l in dt.GetAll() where p.IdParticipant == l.IdParticipant select  p , l    ; ???

I want to display all the columns , and i dont want to do :

p.name , p.job .........

7 Replies

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Pooja Dixit9y ago
try it:
var query = from e in Employee
join d in Dept on e.deptno equals d.deptno
select new {e.deptno, d.deptno};
0
pankaj rai10y ago
to use inner join
ex: from d in table 1
join d1 in table 2 on d.id=d1.id
select new (d.name,d1.name)
-1

Ankur Goel10y ago

Use following LINQ expression:

First data source:data.getAllParticipant()

Second data source: dt.GetAll()

Columns to join: IdParticipant, IdParticipant

Final Output: new {e, e1}

data.getAllParticipant().Join(dt.GetAll()
, e => e.IdParticipant
, e1 => e1.IdParticipant
, (e, e1) => new {e, e1});

-1

Shuvo Sarker10y ago

Example:

var customers = new List {
new Customer { CompanyId = “AC”, CustomerId = “Customer1” },
new Customer { CompanyId = “not-AC”, CustomerId = “Customer2” },
};

var userCustomers = new List {
new UserCustomer { CompanyId = “AC”, CustomerId = “Customer1”, User = “not-admin” },
new UserCustomer { CompanyId = “AC”, CustomerId = “Customer1”, User = “admin” },
new UserCustomer { CompanyId = “AC”, CustomerId = “Customer2”, User = “not-admin” },
new UserCustomer { CompanyId = “AC”, CustomerId = “Customer2”, User = “admin” },
new UserCustomer { CompanyId = “not-AC”, CustomerId = “Customer1”, User = “not-admin” },
new UserCustomer { CompanyId = “not-AC”, CustomerId = “Customer1”, User = “admin” },
new UserCustomer { CompanyId = “not-AC”, CustomerId = “Customer2”, User = “not-admin” },
new UserCustomer { CompanyId = “not-AC”, CustomerId = “Customer2”, User = “admin” } 
};


Linq Expression:

var query = from c in customers join uc in userCustomers on new
{ c.CompanyId, c.CustomerId } equals new { uc.CompanyId, uc.CustomerId }
where c.CompanyId == “AC” && uc.User == “admin“ select c;

Bikesh Srivastava10y ago
Hi,
You can use like this..
varinnerJoinQuery=
fromcategoryincategories
joinprodinproductsoncategory.IDequalsprod.CategoryID
selectnew{ProductName=prod.Name,Category=category.Name};
0
Tapan Patel10y ago
You need to use either join or union in this case (considering accurate design of your table).
http://stackoverflow.com/questions/2767709/c-sharp-joins-where-with-linq-and-lambda
0

Ali Haider10y ago

oining on multiple columns in Linq to SQL is a little different.

var query = from t1 in myTABLE1List // List     join t2 in myTABLE1List       on new { t1.ColumnA, t1.ColumnB } equals new { t2.ColumnA, t2.ColumnB } ...

You have to take advantage of anonymous types and compose a type for the multiple columns you wish to compare against.

This seems confusing at first but once you get acquainted with the way the SQL is composed from the expressions it will make a lot more sense, under the covers this will generate the type of join you are looking for.

EDIT Adding example for second join based on comment.

var query = from t1 in myTABLE1List // List     join t2 in myTABLE1List       on new { A = t1.ColumnA, B = t1.ColumnB } equals new { A = t2.ColumnA, B = t2.ColumnB }     join t3 in myTABLE1List       on new { A = t2.ColumnA, B =  t2.ColumnB } equals new { A = t3.ColumnA, B = t3.ColumnB } ...