c# - Linq issues, joining two tables and a collection -

ok, need suck @ linq!

this collection contains x number of time slot dto's given day.

list<timeslotdto> timeslots = new list<timeslotdto>(); 

the timeslotdto contains datetime slotstart property , bool isreserved. collection works, contains number of timeslots want. fine.

now problem. want use collection in linq query. have 2 tables,"staff" , "timeslots"(well three, if might able add last table query myself)

the "timeslots" table contains:

• staffid(fk)
• timeslotid(pk)
• slotstart
• activityid(fk third table).

the "staff" table contains:

• staffid(pk)
• navigation property timeslots

based on this...i want produce result each staff member has list of timeslots , slots in collection has same date in timeslots table isreserved prop should set true.

so timeslots collection contains possible slots given day. timeslots table contains reservations. want x-check collections find reservations each staff member.

thanks in advance!

if has tutorial on mastering linq, please share it.

you can use contains statement this:

var query = timeslots.where(sl => timeslots.where(t => t.staffid == staffid)                                            .select(t => t.slotstart)                                            .contains(sl.slotstart)); 

this (slightly) better scalable if timeslots contains time slots particular staff.

in query syntax like

var query = sl in timeslots             (from t in timeslots                    t.staffid == staffid                    select(t => t.slotstart))                   .contains(sl.slotstart); 

another option timeslots in memory , join timeslots. (you can't join local collections linq sql backend.)

from sl in timeslots join t in timeslots.where(x => x.staffid == staffid)                    .asenumerable() // switch memory     on ts.slotstart equals t.slotstart 

again assuming timeslots per staff.