linq to sql @identity外键insertonsubmit

Question

我认为你可以用linq做到这一点，但它总是抛出一个外键错误而ContactType.id是0.是否有必要在插入新的ContactType后调用SubmitChanges，或者我是否遗漏了一些基本的东西？

Dim ct As New ContactType
ct.name = "supervisor"
db.ContactTypes.InsertOnSubmit(ct)

Dim c As New Contact
c.ContactTypeId = ct.id
c.first_name = "fname"
c.last_name = "lname"
db.contacts.InsertOnSubmit(c)

db.SubmitChanges()

Answer 1

lucas在此question

中回答{{3}}

必须设置ContactType对象，而不是外键值。

Dim ct As New ContactType
ct.name = "supervisor"
db.ContactTypes.InsertOnSubmit(ct)

Dim c As New Contact
c.ContactType = ct 'this is the important line
c.first_name = "fname"
c.last_name = "lname"
db.contacts.InsertOnSubmit(c)

db.SubmitChanges()

谢谢卢卡斯！