Best Way to Handle Zero to One (Optional) Foreign Key Relationships in MySql

Question

Not sure if this is possible... however I have a table called "LineItems" with a column called "PackageId" -> PackageId IS optional, however i'd still like to somehow setup a foreign key relationship to its relating table Packages - is this possible? If so how might I go about doing it

Also, I will be using the ADO.net Entity Framework Model v4 in conjunction with MySql. i would like to apply this constraint via MySQL (if possible) and have it carry into the Entity Framework model code

thanks!

Loren

Answer 1

我为自己的无知表示歉意，但是我刚刚了解到，通过将列设置为允许null出现，可以让我仍然保留前键关系