Guided, safe migration workflow covering EF Core schema migrations, .NET version upgrades, and NuGet dependency updates — each with rollback strategies and verification steps. Invoke when: "add migration", "update database", "create migration", "schema change", "new table", "rename column", "upgrade

/migrate What The single migration workflow for three change types, with EF Core schema migrations as the primary flow: 1. EF Core schema — review pending model changes, generate a descriptively named migration, review the SQL for data loss and locking risks, apply with a documented rollback path. 2. .NET version upgrade — phased TFM/SDK/package upgrade with verification at each phase. 3. NuGet updates — incremental, one package at a time updates so breakage is always attributable. Shared principles: verify before applying, rollback plan always, test after every step, one logical change per migration. When After modifying entity classes, DbContext configuration, or relationships "add migration", "update database", "create migration", "new table", "rename column" When generating SQL scripts for DBA review "upgrade to .NET 10", "version upgrade", ".NET upgrade" "upgrade nuget", "update packages", "dependency update", vulnerable package alerts How First, classify the request: schema change → Flow A; framework upgrade → Flow B; package update → Flow C. Then follow that flow end to end. Flow A: EF Core Schema Migration (primary) Step 1: Assess current state Check for pending migrations and uncaptured model changes. Step 2: Review model changes Use MCP tools instead of reading whole files: Confirm the change is one logical unit. If not, split into multiple migrations — mixed migrations make rollback all or nothing. Step 3: Generate migration Name describes the change, not the entity: Add Remove Rename Modify + WhatChanged . Step 4: Review generated SQL database update has no dry run flag — preview by generating an idempotent script and reading it: Flag and report: DROP COLUMN / DROP TABLE — confirm data loss is intentional ALTER COLUMN type changes — check precision loss or truncation ALTER on large tables — warn about lock duration New non nullable columns — need defaults for existing rows If data must survive a rename/retype, use a multi step migration with raw SQL: Step 5: Apply and verify Step 6: Document rollback Never modify a migration that is already applied — create a new one. Flow B: .NET Version Upgrade 1. Assess — get project graph to list all TFMs; flag mixed versions. 2. Pre flight — all tests green, no pending EF migrations, dependencies checked for target version compatibility, dedicated branch created (branch IS the rollback plan). 3. Update global.json — SDK version with "rollForward": "latestMinor" . 4. Update TFMs — <TargetFramework net10.0</TargetFramework and <LangVersion 14</LangVersion in .csproj or Directory.Build.props . 5. Update packages — dotnet outdated upgrade Major include Microsoft. , then build and fix. 6. Adopt new features — per knowledge/dotnet whats new.md : TimeProvider , HybridCache , primary constructors, collection expressions. 7. Verify — dotnet build , dotnet test , dotnet format verify no changes . Flow C: NuGet Package Updates 1. Audit — dotnet list package outdated and dotnet list package vulnerable . Vulnerable packages are urgent: update, test, deploy. 2. Categorize — patch (batch safe), minor (one at a time), major (one at a time, read release notes first). 3. Update incrementally — one package, then dotnet build && dotnet test before the next. Batched updates make failures unattributable. 4. Check fit — consult knowledge/package recommendations.md before adding new packages; prefer built in .NET alternatives. Moving off MediatR (commercial license from v13)? Follow the step by step guide in knowledge/mediatr to mediator migration.md . 5. Rollback — git revert the package bump; never downgrade other packages to compensate. MCP Tools Used find symbol / find references — locate entities, assess schema change impact get type hierarchy — entity inheritance for TPH/TPT/TPC get project graph — TFM audit before version upgrades get diagnostics — catch warnings after migration generation or upgrades Example Related ef core — entity configuration, query patterns, migration internals /verify — full verification pipeline after migration work /checkpoint — commit a safe state before risky migrations