Borrowing it
Nothing to install: this file belongs to nerds-odd-e/doughnut. Take a copy, put it at the same path in your own repository, and replace the rules that are about this project with yours.
curl -O https://raw.githubusercontent.com/nerds-odd-e/doughnut/main/.agents/skills/db-migration/SKILL.mdgit clone --depth 1 https://github.com/nerds-odd-e/doughnutWrote this? Show the measurements
A badge with what this costs and how it scanned, read live from this page, so it follows the numbers instead of freezing them. Markdown for a README, HTML for a documentation site or a project page.
[](https://agentmods.dev/skills/nerds-odd-e/doughnut/db-migration)<a href="https://agentmods.dev/skills/nerds-odd-e/doughnut/db-migration"><img src="https://agentmods.dev/badge/skills/nerds-odd-e/doughnut/db-migration/github.svg" alt="Measured on agentmods" height="20"></a>Or the 80×15 button, for a site that already has a row of RSS and ATOM ones. Only the verdict fits; the numbers stay here.
<a href="https://agentmods.dev/skills/nerds-odd-e/doughnut/db-migration"><img src="https://agentmods.dev/badge/skills/nerds-odd-e/doughnut/db-migration.svg" alt="Reviewed on agentmods" width="80" height="20"></a>What it costs to keep this loaded
Counted locally with the o200k_base tokenizer, which is exact for GPT models; Claude uses its own tokenizer and its counts differ. Treat this as one consistent yardstick across the catalogue rather than a bill. Prices are per million input tokens.
| Model | Per session | Once invoked |
|---|---|---|
| Fable 5.1 | $0.00039 | $0.01996 |
| Opus 5.5 | $0.00016 | $0.00798 |
| Sonnet 5.5 | $0.00008 | $0.00399 |
| Haiku 4.5 | $0.00004 | $0.00200 |
Grade A, and why
db-migration scanned grade A with 0 findings against 26 rules in 11 categories — prompt injection, anti-refusal, data exfiltration, privilege escalation, supply chain, agent snooping, system-prompt leakage, SSRF and excessive agency — measured 1mo ago.
A static scan of the body, not an audit. Every finding is printed with the line that produced it so you can judge whether it matters here. A mod is markdown that instructs an agent; that is exactly why what it instructs is worth reading.
Nothing flagged
None of the 26 patterns this scan looks for appear in this file: no shell pipes, no recursive deletes, no credential paths, no hidden text, no instruction-override or anti-refusal phrasing, no agent-config snooping. That is not a guarantee, it is the absence of the things that are checkable.
How it starts
The opening of the file, as written. The whole thing — 104 lines — stays where its author put it; the contents beside it link to each section on GitHub.
Database Migration Guidelines
When to Use This Rule
Use this rule when:
- Creating new database migrations
- Modifying database schema
- Understanding migration file naming conventions
- Working with Flyway migrations
- Troubleshooting migration issues
- Versioning database changes
- Squashing / collapsing historical migrations into the baseline
Migration Tool
The project uses Flyway for database migrations, configured in Spring Boot.
Migration Files Location
- SQL migrations:
backend/src/main/resources/db/migration/ - Java migrations:
backend/src/main/java/db/migration/ - Files follow the naming convention:
V{version}__{description}.sql(or.java)- Example:
V300000352__rename_a_column.sql(version must exceed300000351)
- Example:
Version Numbering
- Versions use a numerical format
The project uses versioned files named V{number}__{description}.sql. The current full application DDL is collapsed into V100000000__baseline.sql; the upgrade migrations after it run in order on every install, and V300000351__db_migration_placeholder.sql is the newest file: a no-op tip placeholder above every version ever applied. Versions 300000330, 300000339, and 300000350 are retired — their migrations were deleted after production applied them — and stay reserved in flyway_schema_history.
New migrations need to use a greater version number than 300000351.
Migration Process
- Migrations run automatically when the application starts (non-test environments)
- Non-test startup runs
flyway.repair()thenflyway.migrate()(FlyWayFreeVersionRealMigration).repair()is what makes squashing safe on existing databases (checksum realign + remove history for deleted files). Deleting the newest applied migration file is different: until a newer version ships, databases that recorded it treat it as a future migration and keep its row unchanged; the next newer migration's startup then marks it deleted. - For unit tests, DB migration is included in the test command (see
backend-developmentrule for test execution)
What this file has done since we first saw it
Hashed on every crawl. A supply-chain change to an agent config is a question of when, not whether, so the history is kept rather than the latest state alone.
- 1mo ago Changed 1aa3d10b6e13
- 1mo ago Changed e0055b3cb3ff
- 1mo ago Changed ce5bd4bd8d15
- 1mo ago Changed 745cf78609ce
- 1mo ago Changed · +6 lines d2a12cc8a2d5
- 1mo ago Changed 5c97459a5089
- 1mo ago Changed 100f2ac07ba5
- 1mo ago First seen · 98 lines · 39 tokens per session scan A 3084a3084600
db-migration is a skill published in the GitHub repository nerds-odd-e/doughnut (50 stars, last pushed today), licensed MIT. It adds 39 tokens to every session and 1,996 once invoked, about $0.0002 per session on Opus 5.5. A static security scan graded it A with 0 findings. No closer match exists in the catalogue, so it is treated as the original; first seen 2026-09-17.
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