Select all columns but group by only one in linq,How to Get only Id fr

Question

Greetings

 

I am using Sharepoint 2016 on Prem

 

I want to Select all columns but apply "group by" only one using LINQ ( retrieve data from Sharepoint list )

 

Problem : Currently having 2 problems/challenges

 

Problem 1: I have lookup field which returns id with name like "23;#abcd" , for this I have to split to get Id only ( mention in below code using split(';').

 

Problem 2: in LINQ query ,I want to select stautus and documentname columns from list not on "group by".

 

Group by is just for 1 column like we do in sql server like below as

 

stautus and documentname feilds are not available in group by so unable to select these 2 fields

select id,stautus ,documentname,comments from abc groupby userFk

My Code:

oQuery.Query = "<Where><Eq><FieldRef Name='Flag'/><Value Type ='number'>" + 1 + "</Value></Eq></Where> ";
var resultfoldeDoc11 = (from SPListItem itm in pLis.GetItems(oQuery)
orderby itm["ID"]
group itm by new { m_folderID22 = itm["DocumentFolderFk"] } into g
select new { m_folderId22 = g.Key.m_folderID22.ToString().Split(';'), m_totaldocsfoldercount = g.Count() });

Solution Required:for Both Problem

 

How can I select multiple columns in select clause with one field in "Groupby " Clause ?

 

How can I get only ID from Look up field in LINQ

 

Thanks