import-export

# Import and Export ## Read First - `src/components/ImportDialog.tsx` and `src/components/ExportDialog.tsx` for UI dispatch. - `src/lib/importer.ts` and `src/lib/importer/` for parser contracts. - `src/workers/sqlite-ddl.worker.ts` for SQLite worker boundaries. - `src/lib/exporter/`, `src/lib/mermaid.ts`, and `src/lib/types.ts` for output and model semantics. ## Change Rules 1. Select the parser from the declared database dialect and keep progress/diagnostic behavior intact. 2. Preserve table and column IDs, positions, colors, locks, notes, zones, viewport, and relationship metadata when the format supports them. 3. Treat custom SQL parsers as dialect-specific state machines. Do not assume MySQL, PostgreSQL, and SQLite syntax coverage is interchangeable. 4. Keep SQLite parsing in the worker and handle worker errors without leaving a half-imported diagram. 5. JSON imports require safe validation before entering the store. Never trust arbitrary node, edge, or date data merely because the top-level arrays exist. 6. DBML save synchronization uses heuristic matching; test similarly named and structurally similar tables, IDs, positions, and repeated save cycles. 7. Generated SQL, DBML, Mermaid, SVG, and migrations are output artifacts. Review quoting, composite keys, comments, notes/zones, and unsupported features explicitly. ## Verification Matrix - Import valid and invalid MySQL, PostgreSQL, SQLite, DBML, and application JSON. - Export and re-import each supported round-trip format where applicable. - Include composite relationships, indexes, comments, nullable/default/generated columns, notes, zones, and locked diagrams when relevant. - Confirm diagnostics are visible and failures do not mutate the active diagram.