linq - How to Merge two lists and Merge it's inner lists without duplication in C# -

i'm trying merge 2 generic list using linq-

list<linkedtable> firstlink list<linkedtable> secondlink 

as shown in class below, generic list has generic list in it.

public class linkedtable {     public string tableid { get; set; }     public string tablename { get; set; }     public list<link> innerlinks { get; set; } }  public class link {     public boolean linkflag;     public string descriptor { get; set; }     public string recordid { get; set; } } 

when merge 2 lists, new list doesn't contain both "innerlinks" records of firstlink , secondlink. have tried following code:

firstlink = firstlink.concat(secondlink)                      .groupby(e1 => e1.tableid)                      .select(e2 => e2.firstordefault())                      .tolist(); 

now firstlink tables grouped "tableid ", few "innerlinks" secondlink missing.

i need both list of "innerlinks" firstlink , secondlink in new merged list without repetition.

example:

firstlink[0].innerlinks[0]             .innerlinks[1]             .innerlinks[2]  secondlink[0].innerlinks[1]              .innerlinks[2]              .innerlinks[3] 

merged link should be:

firstlink[0].innerlinks[0]             .innerlinks[1]             .innerlinks[2]                         .innerlinks[3] 

here's option:

first, you'll have provide way tell linq makes link equal another. can of methods:

• creating class implements iequalitycomparer<link> , pass instance of parameter distinct;
• implementing iequatable<link> , overriding gethashcode on link class
• overriding equals , gethashcode on link class.

assuming recordid unique identifier link object, how implementing iequatable<link>:

public class link : iequatable<link> {     public boolean linkflag;     public string descriptor { get; set; }     public string recordid { get; set; }      public bool equals(link other)     {         //adjust suiting identifier , sanity checks, if needed.         return this.recordid == other.recordid;     }      public override int gethashcode()     {         //you can use gethash approach suits better.         return this.recordid.gethashcode();     } } 

then, can concat both lists, group tableid , tablename. last, use selectmany on grouped linkedtable's innerlinks select links contained on group. distinct have take instance of iequalitycomparer in case opted go way.

var merged =      item in firstlink.concat(secondlink)     group item new { id = item.tableid, name = item.tablename } tbgp     select new linkedtable     {         tableid = tbgp.key.id,         tablename = tbgp.key.name,         innerlinks = tbgp.selectmany(p => p.innerlinks).distinct().tolist()     }; 

selectmany explained on documentation
distinct , iequalitycomparer<t> explained on documentation
distinct , iequatable<t> explained on msdn
overriding equals , gethashcode on msdn