yellowjacket/.planning/milestones/v1.1-phases/10-schema-migration/10-01-SUMMARY.md

phase, plan, subsystem, tags, requires, provides, affects, tech-stack, key-files, key-decisions, patterns-established, requirements-completed, duration, completed

phase	plan	subsystem	tags	requires	provides	affects	tech-stack	key-files	key-decisions	patterns-established	requirements-completed	duration	completed
10-schema-migration	01	database	sqlite migration multi-library phantom-tracks schema		libraries table (name, path, created_at) audio_files.library_id FK column with index playlist_tracks phantom metadata columns (6 fields) playlist_tracks SET NULL FK (was CASCADE) track_metadata VIEW with library_id migration 6 function (multi-library upgrade) pre-migration backup function TOML config cleanup (DirectoryPath removal)	11-per-library-scan 12-library-crud 13-library-views	added patterns Underscore prefix for schema file ordering (_libraries.sql sorts before audio_files.sql) Sentinel library row (id=0) in test DB for FK satisfaction Dynamic DEFAULT in ALTER TABLE ADD COLUMN for backfill TOML read/write with generic map[string]any to preserve unknown sections	created modified backend/database/sql/schemas/_libraries.sql backend/database/database.go backend/database/sql/schemas/audio_files.sql backend/database/sql/schemas/playlist_tracks.sql backend/database/sql/schemas/track_metadata_view.sql backend/database/sql/sqlcgen/audio_files.sql.go backend/database/sql/sqlcgen/models.go backend/database/sql/sqlcgen/playlists.sql.go backend/database/testhelper.go backend/playlist/playlist.go	Underscore prefix _libraries.sql for embedded FS sort order (libraries table must exist before audio_files FK) Sentinel library id=0 in NewTestDB so existing tests using DEFAULT library_id=0 continue working TOML cleanup uses generic map[string]any to preserve all config sections, only deletes DirectoryPath Backup skipped for in-memory databases (test environments)	_libraries.sql naming convention for schema ordering sql.NullInt64 for nullable FK columns in playlist_tracks	DATA-01 DATA-04 LSCAN-05	11min	2026-03-09

Phase 10 Plan 1: Schema & Migration Summary

Libraries table, audio_files.library_id FK, playlist_tracks phantom columns with SET NULL FK, migration 6 with pre-backup and TOML config cleanup

Performance

• Duration: 11 min
• Started: 2026-03-09T13:29:50Z
• Completed: 2026-03-09T13:41:26Z
• Tasks: 2
• Files modified: 10

Accomplishments

• Created libraries table schema with name, path, created_at columns
• Added library_id FK to audio_files with index for filter performance
• Rebuilt playlist_tracks with nullable audio_file_id (SET NULL FK) and 6 phantom metadata columns
• Implemented migration 6 with 14-step process: backup, TOML read, FK OFF, create table, insert default library, add column, rebuild playlist_tracks, backfill phantom metadata, recreate VIEW, FK ON, TOML cleanup, version bump
• Updated track_metadata VIEW to include library_id
• Regenerated sqlc code and fixed all callers for nullable AudioFileID

Task Commits

Each task was committed atomically:

1. Task 1: Update SQL schema files for fresh installs - 535855b (feat)
2. Task 2: Implement migration 6 and pre-migration backup - 1179f56 (feat)

Files Created/Modified

• backend/database/sql/schemas/_libraries.sql - New libraries table DDL
• backend/database/sql/schemas/audio_files.sql - Added library_id column and FK
• backend/database/sql/schemas/playlist_tracks.sql - Nullable audio_file_id, SET NULL FK, 6 phantom columns
• backend/database/sql/schemas/track_metadata_view.sql - Added af.library_id to SELECT
• backend/database/database.go - migration6MultiLibrary(), backupDatabase(), TOML helpers
• backend/database/sql/sqlcgen/models.go - Library struct, updated AudioFile and PlaylistTrack
• backend/database/sql/sqlcgen/audio_files.sql.go - Updated queries for library_id column
• backend/database/sql/sqlcgen/playlists.sql.go - sql.NullInt64 for AudioFileID, phantom fields
• backend/database/testhelper.go - Sentinel library row, updated runMigrations call
• backend/playlist/playlist.go - sql.NullInt64 wrapping for AddPlaylistTrack calls

Decisions Made

• Used underscore prefix _libraries.sql to ensure correct embedded FS sort order (libraries must exist before audio_files FK reference)
• Sentinel library row at id=0 in NewTestDB for backward compatibility with existing test data using DEFAULT library_id=0
• TOML config cleanup uses generic map[string]any decode to preserve all config sections when removing only DirectoryPath
• Backup function skips for in-memory databases (:memory: path check) to support test environments

Deviations from Plan

Auto-fixed Issues

1. [Rule 3 - Blocking] Regenerated sqlc code and fixed compilation errors

• Found during: Task 1 (SQL schema updates)
• Issue: Pre-commit hook auto-ran sqlc generate which updated generated code — AudioFileID changed from int64 to sql.NullInt64, breaking 4 call sites in playlist.go
• Fix: Added database/sql import to playlist.go and wrapped all AudioFileID assignments with sql.NullInt64{Int64: id, Valid: true}
• Files modified: backend/database/sql/sqlcgen/{models,audio_files.sql,playlists.sql}.go, backend/playlist/playlist.go
• Verification: go build ./... passes
• Committed in: 535855b (Task 1 commit)

2. [Rule 3 - Blocking] Fixed test FK constraint failures

• Found during: Task 2 (migration implementation)
• Issue: Existing tests insert audio_files with DEFAULT library_id=0 but no library with id=0 exists after schema changes — FK constraint violated
• Fix: Added sentinel library row (id=0, name='Test', path='/test') in NewTestDB() so all tests have a valid FK target
• Files modified: backend/database/testhelper.go
• Verification: go test ./backend/database/... -count=1 passes (all 10+ test functions)
• Committed in: 1179f56 (Task 2 commit)

3. [Rule 1 - Bug] Fixed unchecked error returns on file Close()

• Found during: Task 2 (linter pre-commit check)
• Issue: src.Close() and dst.Close() in backupDatabase() had unchecked error returns, caught by errcheck linter
• Fix: Changed to defer func() { _ = src.Close() }() pattern (explicit discard)
• Files modified: backend/database/database.go
• Verification: golangci-lint passes with 0 issues
• Committed in: 1179f56 (Task 2 commit)

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Total deviations: 3 auto-fixed (2 blocking, 1 bug) Impact on plan: All fixes necessary for correctness and build health. No scope creep — sqlc regeneration and test fixes are direct consequences of the schema changes.

Issues Encountered

None — migration 6 follows established patterns from migration 5.

User Setup Required

None - no external service configuration required.

Next Phase Readiness

• Schema foundation complete for multi-library support
• Ready for Plan 02 (sqlc query updates, if applicable) or Phase 11 (per-library scan pipeline)
• All existing tests pass with new schema

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Phase: 10-schema-migration Completed: 2026-03-09