Modeling, DbContext configuration, migrations

Data Binding with EF CoreModule 2The lesson guide, the walkthrough video, the knowledge check and the hands-on lab this sample was built from are on learnwisej.com — free, with an AI tutor in every lesson.

Open the course

The Support Desk model arrives: Customer, Agent, Category, Ticket and TicketComment, configured with the Fluent API (required strings and lengths, a RowVersion concurrency token, the planned indexes, one OnDelete rule per relationship and a CHECK constraint on the title), scaffolded into the InitialCreate migration through the design-time factory, applied with MigrateAsync at start in Development, and filled by a development-only seeder.

The source of this sample

iceteagroup/LearnWisej-SamplesData Binding with EF Core Course/Module 2

Browse this folder on GitHub

Or clone it: git clone https://github.com/iceteagroup/LearnWisej-Samples.git — then open SupportDesk.slnx in Visual Studio and press F5.

Run it

cd "LearnWisej-Samples/Data Binding with EF Core Course/Module 2/SupportDesk.Web"
dotnet run -f net10.0 --urls http://localhost:5402

In Development the host migrates and seeds SupportDesk.Web/App_Data/supportdesk.db before the first session (five customers, three agents, six categories, sixty tickets, sixteen comments). Delete the file (and its -wal / -shm companions) to start over. Tests: dotnet test SupportDesk.Tests.

Migration commands, from the Module 2 folder (--framework is needed because the web project multi-targets):

dotnet ef migrations list   --project SupportDesk.Data --startup-project SupportDesk.Web --framework net10.0
dotnet ef migrations script --idempotent --project SupportDesk.Data --startup-project SupportDesk.Web \
    --framework net10.0 --output artifacts/sql/supportdesk_migrations.sql

What to try

The page has countButton, btnSeed, statusLabel, a counts line (customers, agents, categories, tickets, pending migrations) and the two failure paths lab step 8 asks for.

• Count tickets: 60 tickets in the Support Desk database.
• Seed development data (btnSeed): the database is seeded at start, so it reports nothing to seed: 60 tickets already exist. On an empty database it seeds and the counts line updates.
• Save a 200-character title: the CHECK constraint refuses the insert; a friendly AlertBox says the database rejected the change, the counts do not move, and the exception goes to the console log.
• Delete a customer with tickets: DeleteBehavior.Restrict refuses it; This customer still has tickets and cannot be deleted.