asp.net - many - to many relationship handling issue in entity framework -

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i've got table

tourists

  1. tourist_id

    2.name

extra_charges

  1. extra_charge_id
  2. description

toutist_extra_charges

  1. tourist_extra_charge_id - primary key
  2. tourist_id - foreign key
  3. extra_charge_id - foreign key

i try make sql query using entity framework ent

    "select tourist.name, extra_charges.extra_charge_description, tourist  left join tourist_extra_charges on tourist.tourist_id = tourist_extra_charges.tourist_id  left join extra_charges on tourist_extra_charges.extra_charge_id = extra_charges.extra_charge_id tourist.tourist_id=86

i want name of tourist id=86(event if doesn't have extra_charges) , if have extra_charges - description of extra_charge

as i'm new entity framework tried following

foreach (var tourist in db2.tourist.include("tourist_extra_charges").include("extra_charges").where(x=>x.tourist_id==86))                   {                       lblproba.text+="name" + tourist.name_kir+" description" + tourist.tourist_extra_charges.//don't have access extra_charges table                     }

but when type tourist.tourist_extra_charges don't have access extra_charges table , description column

edit:

i read use entity framework mapping many-to-manyrelationship should delete column tourist_extra_charge_id , make compository primary key. when did - , made new edmx model - can't see tourist_extra_charges table. , nomatter how many times created model - table didn't occur in model

i can't see tourist_extra_charges table

that's expected link table in many-to-many relationship , don't need table entity.

your tourist entity should have collection extra_charges , can perform query so:

var tourist = db2.tourist     .include("extra_charges")     .singleordefault(t => t.tourist_id == 86);  if (tourist != null) {     lblproba.text += "name "         + tourist.name_kir         + " description "         + string.join(", ", tourist.extra_charges.select(e => e.description)); }

i have replaced foreach loop singleordefault because querying primary key can have 1 result (or none). extra_charges.select(e => e.description) extracts description each charge , returns new collection of strings. string.join concats descriptions in collection , separates them comma.


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