---
name: ef-core-migration
description: Tạo/sửa/revert EF Core 10 migration cho SOLUTION_ERP. Dùng khi thêm entity mới, thay đổi schema, rollback migration, debug DesignTimeDbContextFactory fail. Đã có 8 migration sẵn (Init → AddVersionedWorkflows). Snapshot + Designer + Migration 3-file rule bắt buộc commit đủ.
when-to-use:
  - "thêm migration"
  - "EF Core migration"
  - "dotnet ef migrations add"
  - "revert migration"
  - "schema DB update"
  - "DbContext change"
  - "snapshot lỗi"
  - "DesignTimeDbContextFactory"
---

# EF Core Migration — SOLUTION_ERP

> **Context:** .NET 10 + EF Core 10 + SQL Server. DbContext: `ApplicationDbContext` ở `Infrastructure/Persistence/`. Startup: `SolutionErp.Api`.

## Migration history (8 migration hiện có)

| # | Name | Tables added / changed |
|---|---|---|
| 1 | `Init` | 7 Identity tables (AspNetUsers/Roles/UserRoles/...) |
| 2 | `AddMasterData` | Suppliers, Projects, Departments |
| 3 | `AddPermissions` | MenuItems, Permissions |
| 4 | `AddForms` | ContractTemplates, ContractClauses |
| 5 | `AddContractsWorkflow` | Contracts, ContractApprovals, ContractComments, ContractAttachments, ContractCodeSequences |
| 6 | `AddNotifications` | Notifications |
| 7 | `AddWorkflowTypeAssignments` | WorkflowTypeAssignments (legacy admin override) |
| 8 | `AddVersionedWorkflows` | WorkflowDefinitions, WorkflowSteps, WorkflowStepApprovers + `Contracts.WorkflowDefinitionId` FK |

Total: **24 bảng** dbo + `__EFMigrationsHistory`. Xem `docs/database/schema-diagram.md` ERD đầy đủ.

## Commands (chạy từ root repo)

### Thêm migration mới

```powershell
# Sau khi chỉnh Domain entity + EF config + DbContext DbSet
dotnet ef migrations add <MigrationName> `
  --project src/Backend/SolutionErp.Infrastructure `
  --startup-project src/Backend/SolutionErp.Api `
  --output-dir Persistence/Migrations
```

**Naming convention:** PascalCase, verb prefix:
- `Add<Thing>` — thêm entity / bảng
- `Update<Thing>` — thay đổi schema
- `Remove<Thing>` — xóa column / table
- `Rename<Thing>` — đổi tên

### Apply migration to DB

```powershell
# Dev: LocalDB SolutionErp_Dev
dotnet ef database update `
  --project src/Backend/SolutionErp.Infrastructure `
  --startup-project src/Backend/SolutionErp.Api

# Hoặc đơn giản: chạy API → DbInitializer tự Migrate
dotnet run --project src/Backend/SolutionErp.Api
```

### Revert 1 migration (rollback)

```powershell
# Rollback về migration trước đó (ví dụ về sau AddWorkflowTypeAssignments)
dotnet ef database update AddWorkflowTypeAssignments `
  --project src/Backend/SolutionErp.Infrastructure `
  --startup-project src/Backend/SolutionErp.Api

# Xóa file migration (3 file, xem dưới)
dotnet ef migrations remove `
  --project src/Backend/SolutionErp.Infrastructure `
  --startup-project src/Backend/SolutionErp.Api
```

### Gen SQL script (review trước khi apply prod)

```powershell
# Script từ 1 migration → latest
dotnet ef migrations script AddWorkflowTypeAssignments `
  --project src/Backend/SolutionErp.Infrastructure `
  --startup-project src/Backend/SolutionErp.Api `
  --output tmp/migration-7-to-8.sql

# Idempotent (check if exists trước mỗi operation)
dotnet ef migrations script --idempotent `
  --project src/Backend/SolutionErp.Infrastructure `
  --startup-project src/Backend/SolutionErp.Api
```

## 3-file rule (BẮT BUỘC commit đủ)

Mỗi `migrations add` sinh **3 file** — phải commit đủ:

```
src/Backend/SolutionErp.Infrastructure/Persistence/Migrations/
├── {Timestamp}_{Name}.cs              ← migration logic (Up/Down)
├── {Timestamp}_{Name}.Designer.cs     ← model snapshot tại thời điểm migration
└── ApplicationDbContextModelSnapshot.cs  ← current model state (được overwrite mỗi migration)
```

**Gotcha #17:** Thiếu `ModelSnapshot.cs` → `migrations add` kế tiếp sẽ sinh duplicate columns. Thiếu `Designer.cs` → không revert được.

## Pitfalls thường gặp

### P1 — DesignTime DbContext resolve fail

**Triệu chứng:** `dotnet ef migrations add` → `Unable to resolve service for type 'DbContextOptions<ApplicationDbContext>'`.

**Nguyên nhân:** EF tooling chạy đứng ngoài runtime DI, cần factory riêng.

**Fix:** Đã có `src/Backend/SolutionErp.Infrastructure/Persistence/DesignTimeDbContextFactory.cs`. Nếu connection string thay đổi → update factory, không chỉ `appsettings.json`.

### P2 — Table rename / column rename gen ra DROP + CREATE

**Triệu chứng:** Migration sinh `DropColumn` + `AddColumn` thay vì `RenameColumn` → mất data.

**Fix:** Sửa migration thủ công sang `migrationBuilder.RenameColumn(...)`. Hoặc dùng `[Column("newname")]` attribute để EF tự detect rename.

### P3 — Query filter (soft delete) khi thêm FK

**Triệu chứng:** Warning `The entity type 'X' has a global query filter but referencing entity 'Y' doesn't. This may lead to inconsistent results`.

**Fix:** Entity reference cũng phải có query filter:
```csharp
builder.HasQueryFilter(x => !x.IsDeleted);
```

Hoặc dùng `.IgnoreQueryFilters()` cho query cần bypass.

### P4 — FK cascade/restrict khác với expectation

**Triệu chứng:** Migration apply OK nhưng DELETE parent → cascade sang child (hoặc ngược lại restrict block).

**Fix:** Explicit config trong `IEntityTypeConfiguration<T>`:
```csharp
builder.HasOne(x => x.Contract)
    .WithMany(c => c.Approvals)
    .HasForeignKey(x => x.ContractId)
    .OnDelete(DeleteBehavior.Cascade);  // hoặc Restrict, SetNull
```

**Case study quan trọng:** `Contracts.WorkflowDefinitionId` → `WorkflowDefinitions.Id` **PHẢI dùng `Restrict`** để protect HĐ cũ khi admin archive version (xem `workflow-contract.md` invariants).

### P5 — Nullable reference type gen column NOT NULL

**Triệu chứng:** Property `public string? Description` → migration gen `NOT NULL`.

**Fix:** Check `builder.HasQueryFilter` chỗ config, hoặc explicit `builder.Property(x => x.Description).IsRequired(false)`.

### P6 — `AddVersionedWorkflows` duplicate seed

**Case study hiện tại:** Nếu thêm migration mới sau `AddVersionedWorkflows`, cẩn thận KHÔNG trigger `DbInitializer.SeedWorkflowDefinitionsAsync` 2 lần. Check `if (!db.WorkflowDefinitions.Any())` trong DbInitializer.

## Workflow khi thêm entity mới (example: add AuditLog)

```
1. Domain/AuditLogs/AuditLog.cs — tạo entity (BaseEntity hoặc AuditableEntity)
2. Infrastructure/Persistence/Configurations/AuditLogConfiguration.cs
   - ToTable("AuditLogs")
   - Unique index trên (EntityType, EntityId) nếu cần
3. Infrastructure/Persistence/ApplicationDbContext.cs
   - public DbSet<AuditLog> AuditLogs => Set<AuditLog>();
4. Application/Common/Interfaces/IApplicationDbContext.cs
   - DbSet<AuditLog> AuditLogs { get; }
5. dotnet ef migrations add AddAuditLogs
6. Review file .cs sinh ra → OK
7. dotnet ef database update → LocalDB apply
8. Test: dotnet run → check bảng được tạo
9. Commit [CLAUDE] Domain+Infra: add AuditLog entity + migration
10. ⚠️ UPDATE docs/database/schema-diagram.md (ERD + migration table)
11. UPDATE docs/STATUS.md nếu là work lớn
```

## Apply prod (VPS)

```powershell
# Trên VPS, sau khi deploy code:
# Option 1: auto migrate — DbInitializer.MigrateAsync() chạy khi API startup
# Option 2: manual script
dotnet ef migrations script <LastApplied> --idempotent --output migrate.sql
# Review migrate.sql → chạy qua sqlcmd:
sqlcmd -S .\SQLEXPRESS -d SolutionErp -U vrapp -P <pw> -i migrate.sql
```

**Prod safety:**
- Backup trước: `scripts/backup-sql.ps1`
- Dry-run idempotent script local trước
- Test rollback plan: script from-N-to-M-1 sẵn

## Code pointers

- `src/Backend/SolutionErp.Infrastructure/Persistence/ApplicationDbContext.cs` — 24 DbSet
- `src/Backend/SolutionErp.Infrastructure/Persistence/DesignTimeDbContextFactory.cs` — EF tooling factory
- `src/Backend/SolutionErp.Infrastructure/Persistence/DbInitializer.cs` — seed + warn + migrate runtime
- `src/Backend/SolutionErp.Infrastructure/Persistence/Configurations/` — 24 IEntityTypeConfiguration
- `src/Backend/SolutionErp.Application/Common/Interfaces/IApplicationDbContext.cs` — interface Application layer

## Related

- `docs/database/database-guide.md` — conventions + migration workflow chi tiết
- `docs/database/schema-diagram.md` — ERD 24 bảng
- `docs/gotchas.md` #7, #17 — migration pitfalls
