Real Data Architecture: EF Core, Transactions, Repositories & Commands

Enterprise Wisej.NET: Architecture to CloudModule 4The 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.

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The EnterpriseOps Command Center's Approvals screen, in front of a real Entity Framework Core database. The fake WorkOrderService of the earlier modules is gone: Create, Update, Approve, Search and Audit are EF Core operations behind a service boundary, each with an explicit transaction boundary and every database failure mapped to a result code, a user message and an audit row.

The screen is the approve panel next to the work queue: pick a work order, type a comment, click Approve. The handler builds an ApproveWorkOrderCommand, hands it to the service and shows the CommandResult; the service authorizes, creates a short-lived DbContext, opens a transaction, loads by tenant + id, checks the version, validates the transition, persists, audits and commits.

EF Core. Microsoft.EntityFrameworkCore.Sqlite 10.0.12, over an in-memory SQLite database (DataSource=:memory:) created fresh per session: no file, no server, no network.

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The source of this sample

iceteagroup/LearnWisej-SamplesEnterprise Wisej.NET Course/Module 4

Browse this folder on GitHub

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

Run it

cd "Module 4/EnterpriseOps"
dotnet run -f net10.0 --urls http://localhost:5204

Then open http://localhost:5204. Every browser session gets its own database and its own SessionContext — nothing is shared and nothing is static.

Signed in as ana.ops (Manager), tenant fabrikam, with 60 seeded work orders across three tenants. Work order WO-2002 — Repair loading dock pump is selected on load: OnHold, v8, exactly as it.

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What to click

Control	Path	What you should see
Approve with WO-2002 selected	failure (the first click)	Red banner "This work order is on hold — resolve the hold before approving.", detail WO_STATE_INVALID · transaction rolled back · nothing persisted, status bar CommandResult.Fail — WO_STATE_INVALID · rolled back · audited
Approve with an InProgress row selected	success (the second click)	Green banner "Work order approved.", detail committed · audit written · correlation …, status bar CommandResult.Ok — committed · v3 → v4 · audited; the grid refreshes and the row is Completed with a new version
Approve with the comment box emptied	validation	VALIDATION_FAILED — "An approval comment is required." Validation happens in the service, not in the screen
Cancel	UI only	Clears the comment and the banner; nothing is sent to the service
txtSearch + Search	read side	The grid reloads with WorkQueueRow projections (one short-lived DbContext, AsNoTracking)
Audit log	dialog	await dialog.ShowDialogAsync() over AuditLogRow projections: every committed and every rejected command with its code, user and correlation id. The query service checks the ReadAudit permission before running anything

The services write each step (Security:, Data:, Service:, Audit:) to the server log through Services/ActivityTrace.cs → System.Diagnostics.Trace (the debugger's Output window).

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Where things live

EnterpriseOps/
  Program.cs                           Application.MainPage = new UI.ApprovalsPage();
  UI/          ApprovalsPage (work queue · approve panel · status bar), AuditLogDialog
  Domain/      WorkOrder, AuditEntry, Tenant, WorkOrderStatus, Priority, WorkOrderTransitions
  Services/    IWorkOrderCommandService, IWorkOrderQueryService, SessionContext,
               IActivityTrace + ActivityTrace (server log) + NullTrace (tests),
               Commands/ (Create/Update/ApproveWorkOrderCommand, CommandContext, CommandResult),
               Queries/  (WorkQueueQuery, WorkQueueRow, PagedResult<T>, AuditLogRow, AuditQueryResult)
  Data/        EnterpriseOpsDbContext, SessionDatabase, SeedData, IWorkOrderRepository, WorkOrderRepository,
               WorkOrderCommandService, WorkOrderQueryService, ErrorMap, DataArchitecturePatterns (the file)
  Security/    Permissions (roles, operations, server-side rules)
  docs/        the five deliverables + the boundary SVG

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Production readiness

• Would not change. The boundary, the command and result classes, the transaction shape, the error codes and messages, the per-operation context lifetime, the audit-after-rollback rule.
• Provider. Swap UseSqlite(connection) for UseSqlServer(connectionString) in SessionDatabase, drop the session-long connection (a real server has a pool), and swap the provider checks in ErrorMap.Map (SQL Server: 2601/2627 unique, 547 foreign key, −2 timeout). The result codes stay.
• Concurrency token. int Version becomes rowversion (byte[]), as the ApproveWorkOrderCommand sketches.
• Schema. EnsureCreated() + SeedData becomes EF Core migrations applied by the pipeline.
• Concurrency control. SessionDatabase.Gate exists because one in-memory SQLite connection is shared by a session; with a pooled connection it can go.
• Retries. A real provider needs a transient-fault policy (EF Core's execution strategy) around the transaction.
• Diagnostics. The ActivityTrace lines become structured log events keyed by the correlation id (Module 11).

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