c# - Entity Framework LINQ Insert -


i'm trying use linq insert object in database. primary key auto increment. need increment id in code or entity framework can it?

i have dbcontext:

travelagencyentities db = new travelagencyentities();

i'm trying insert user object:

user newuser = new user();         newuser.firstname = firstname.text.tostring();         newuser.lastname = lastname.text.tostring();         newuser.email = email.text.tostring();         newuser.password = password.text.tostring();          db.users.add(newuser);         db.savechanges();

it returns exception:

{"an error occurred while updating entries. see inner exception details."}

i think error because not set id in object, should auto increment. know problem?

the inner error:

cannot insert explicit value identity column in table 'user' when identity_insert set off

if use code first, have set following code in dbcontext onmodelcreating. 

protected override void onmodelcreating(dbmodelbuilder modelbuilder) {     base.onmodelcreating(modelbuilder);      modelbuilder.entity<user>()         .property(a => a.id)         .hasdatabasegeneratedoption(databasegeneratedoption.none); }

or set attribute following

public class user {     [key]     [databasegenerated(databasegeneratedoption.none)]     public int id { get; set; }      ..... }

you must change none identity. identity option default key.


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