Join using linq

abdolwahab alemi

14y2.8kLINQ

hi

i have 4 list that I need to join together

public class Person
{
public int personid { get; set; }

public string fname { get; set; }

public string lname { get; set; }
}

public class Department
{
int depid { get; set; }

string departmentname { get; set; }
}

public class Group
{
public int groupid { get; set; }

public int depid { get; set; }

public string groupname { get; set; }
}

public class UploadFile
{
public int fileid { get; set; }

public int personid { get; set; }

public int groupid{ get; set; }

public string filename { get; set; }
}

List filelist=getFiles();

List personlist=getPersons();

List departmentlist=getDepartments();

List grouplist=getgroups();

I need an output like:

fileid fname lname filename path

1 Jon ... ... departmentname+">"+groupname

thanks!

3 Replies

Know the answer? Post it — somebody with the same question will find it here.

Vulpes14y ago
Accepted answer
Try:

var query = from p in personlist
join u in filelist on p.personid equals u.personid
join g in grouplist on u.groupid equals g.groupid
join d in departmentlist on g.depid equals d.depid
select new{u.fileid, p.fname, p.lname, f.filename, path = d.departmentname + ">" + g.groupname};
Ajay Patel14y ago
Here is Sample for All Joins Using Linq

http://ajaypatelfromsanthal.blogspot.in/2012/05/joins-in-linq.html
Senthilkumar14y ago
Hi,

You need to join by the key fields.

var query = from p in personlist
join u in filelist on p.personid equals u.personid
join g in grouplist on u.groupid equals g.groupid
join d in departmentlist on g.depid equals d.depid
select new{u.fileid, p.fname, p.lname, f.filename, path = d.departmentname + ">" + g.groupname};

var query = from P in Personlist
join D in Departmentlist on D.depid equals G.depid
join G in Grouplist on G.groupid equals U.groupid
join U in Filelist U.personid equals P.personid
select new { U.fileid,P.fname,P.lname, path = U.filename + ">" + U.Path };

The query will have the joined table results.
Now you can iterate the results.

// Display joined groups.
foreach (var group in query)
{
Console.WriteLine(group.fileid+" "+ group.fname+" "+group.lname+" "+group.path);
}

Hope this will help you.