How to bind two table in gridview in asp.net

Question

i want to bind two table in gridview.

The first Table has username,  userid, mailid,Roleid (int) are there and

the second table has  Roleid (int) and rolename ( varchar(50)) are there.

 

first table roleid is foreign key and second table roleid is primary key.

which is refffered by rolename 

 

and my expected result is

 

user name  from first table

role name from second table and it should comes by dropdownlist

how can i get this.

 

 

if i edit my dropdownlist is grid means it should change the  values in database can anyone give the code for me