c# - need help around IQueryable query result -

assuming following tables

person

• id
• name

personteam

• id
• person_id
• is_supervisor
• team_id

team

• id

timesheet

• id
• team_id

i obtain timesheets supervisor. got name of supervisor, need select team got supervisor role. select time sheet of teams.

i believe following query does

var alltimesheets = ctx.personteam.where(y => y.person.name == supervisor_name).where(x => x.is_supervisor == true).select(z => z.team).select(t => t.timesheet); 

afer operation cannot understand alltimesheets a

 iqueryable<icollection<timesheet>> 

i expected more a

 <icollection<timesheet>> 

or ienumrable.

then questions :

1. why got kind of result ?
2. how obtain timesheet[] got iqueryable < icollection < timesheet > > ?

why did kind of result ? expected more icollection<timesheet>

an iqueryable<t> is ienumerable<t>. reason it's returning iqueryable can chain other methods orderby onto , project actual sql.

i realized you're asking. "flatten" collection of collections, use selectmany instead of 2 chained selects:

var alltimesheets = ctx.personteam                        .where(y => y.person.name == supervisor_name                                  && y.is_supervisor == true)                        .selectmany(z => z.team, (z, t) => t.timesheet); 

the answer second question still applies:

how obtain timesheet[] iqueryable<icollection<timesheet>>

(first of use first part change iqueryable<timesheet>)

you can call 1 of "conversion" methods toarray, tolist, "hydrate" query concrete type.

you can call "asenumerableto cast anienumerableto convert query linq-to-objects, has better support custom functions in sorts, filters, etc. note callingasenunerable` no immediately fetch objects, as collection in enumerated.