Sign Up to our social questions and Answers Engine to ask questions, answer people’s questions, and connect with other people.
Login to our social questions & Answers Engine to ask questions answer people’s questions & connect with other people.
Lost your password? Please enter your email address. You will receive a link and will create a new password via email.
Please briefly explain why you feel this question should be reported.
Please briefly explain why you feel this answer should be reported.
Please briefly explain why you feel this user should be reported.
I’m programmatically creating an edmx file as part of our code generation process and I’d like to know how the designer decides to use “1” or “0..1” for a relationship when you “Update model from database”. Any insight on this? Thanks
Edit:
Ok, I think it uses “0..1” when the “many” side is a nullable foreign key and “1” if it’s not nullable. Can anyone confirm this?
Yes, setting “0..1” or “1” for the Parent relation role depends upon the fact whether the column is nullable or not.
Don’t forget that if the relation is built over parts of primary key columns from both tables(1 to 1 association) the cardinality will be 1 (Parent) to 0..1 (Child).
If you are developing a new edmx-generation tool, we recommend you to experiment and analyze as much as possible. We have developed a design time tool for generating and editing Entity Framework and LINQ to SQL models with further code generation for Oracle, MySQL, PostgreSQL, SQL Server and SQLite for our customers. There were no problems with SQL Server, because Entity Framework was initially developed over it, but other databases revealed some difficulties. There even was an impression that some peculiarities of Oracle database,for example, were not taken into account at all.