Question

I have a table table1, the primary key is Pkey. It is an identity column. I have another table table2 that has no primary key and identity column.

I want to insert the value of Pkey of table1 into id column of table2.

obj2.id = obj1.Pkey;

I get an exception:

Cannot insert the value NULL into column ‘id’, table ‘table2’; column does not allow nulls. INSERT fails.

Thanks for hint. Does the system want to assign the identity property to id?

UPDATE:

Origninally table2 is empty, I created new record from entity framework.

BDetail obj2= iContext.DetailsRecords.Create();
obj2.id = obj1.Pkey;
iContext.BDetail.Add(obj2);
iContext.SaveChanges(); // exception here

Answer 1

Is it possible that obj1 hasn’t been created yet? Hence the NULL value from a primary key (which, if the row exists, can never be NULL).