- Implement upsert logic in import_phone() function
- Check for existing (id, phone) combinations before insert
- Track duplicates within CSV to skip gracefully
- Update existing records instead of failing on duplicates
- Add detailed statistics: inserted, updated, skipped counts
- Align with upsert pattern used in other import functions
- Add documentation in docs/PHONE_IMPORT_FIX.md
Fixes: UNIQUE constraint failed: phone.id, phone.phone error
when re-importing or uploading CSV with duplicate entries
- Implement upsert (INSERT or UPDATE) logic for all reference table imports
- Fixed functions: import_trnstype, import_trnslkup, import_footers,
import_filestat, import_employee, import_gruplkup, import_filetype,
import_fvarlkup, import_rvarlkup
- Now checks if record exists before inserting; updates if exists
- Makes imports idempotent - can safely re-run without errors
- Added tracking of inserted vs updated counts in result dict
- Maintains batch commit performance for large imports
- Fixes sqlite3.IntegrityError when re-importing CSV files
- Changed encoding fallback order to prioritize iso-8859-1/latin-1 over cp1252
- Increased encoding test from 1KB to 10KB to catch issues deeper in files
- Added proper file handle cleanup on encoding failures
- Resolves 'charmap codec can't decode byte 0x9d' error in rolodex import
- Tested with rolodex file containing 52,100 rows successfully
- Created IMPORT_GUIDE.md: Complete user guide with step-by-step instructions
* Detailed import order for all 27+ tables
* Troubleshooting guide
* Data validation procedures
* Best practices and performance notes
- Created IMPORT_SYSTEM_SUMMARY.md: Technical implementation summary
* Complete list of all implemented functions (28 import + 7 sync)
* Architecture and data flow diagrams
* Module organization
* Testing status and next steps
* ~3,000 lines of code documented
