c# - How to insert a new record which has a auto increment number as primary key? -

for example, have following table:

customerinfo

cus_id: auto increment, int, identity cus_name: nvarchar 

if use follow codes insert record "peter",

string name = "peter"; datacontext dc = new datacontext(); customerinfo newcustomer = new customerinfo(); newcustomer.cus_name = name;  dc.customerinfos.insertonsubmit(newcustomer); dc.submitchanges(); 

the following error returns,

can't perform create, update, or delete operations on 'table(customerinfo)' because has no primary key.

do need self-define cus_id or other solutions? thanks!

first of linq-to-sql needs primary keys in order able inserts , updates, have add primary key in table.

now, because auto incremented identity column, in dbml, have select column "cus_id" of "customerinfo" table , go properties , set following:

• auto generated value : true
• auto-sync : oninsert

this ensure when insert new row new id.