csharp.examples

The examples all use MSSQL Server so that

dotnet tool install --global dotnet-ef
// make sure db exists -- i.e. Blog
dotnet ef database update

To create the migration and generate the sql

cd src/CSharpExamples

rm sql -Force -Recurse
rm Relationships\Migrations -Force -Recurse

dotnet ef migrations add "Initial" --project .\Relationships\Relationships.csproj
dotnet ef database update --project .\Relationships\Relationships.csproj
dotnet ef migrations script --no-build --idempotent --project .\Relationships\Relationships.csproj --output sql/table/EFCore.migration.sql

Relationships

The two relationships in this model are:

• Each Order can have many Items (one-to-many):
  • Order is an aggregate root.
  • OrderItem a dependent/child. It contains the FK property OrderItem.OrderId, the value of which must match the Order.OrderId PK value of the related order.
  • Order.Items is a collection navigation from an order to all the associated items. There is no inverse mapping to get from child to parent.
• Each Order can have one Address (one-to-one):
  • Order is the aggregate root.
  • Address is the dependent/child. Order has a reference navigation to the Address. There is no inverse navigation from Address to Order
  • Order implies an FK to Address in the table definition, but does not expose AddressId outside of the Address child.
• Each Item can have many suppliers and each supplier can have many items (many-to-many):
  • Many-to-many relationships are a further layer over two one-to-many relationships.
  • Item.Suppliers is a collection navigation from an item to all the associated suppliers. There is no inverse navigation for Supplier.