Migrating from Odoo 17 to 19:
Breaking Changes, Upgrade Path & Testing Strategy

# Create a dedicated staging database
sudo -u postgres createdb -O odoo production_v19_staging

# Restore the v19-migrated dump from Odoo's upgrade service
pg_restore -U odoo -d production_v19_staging \
  --no-owner --no-privileges \
  /tmp/odoo19_migrated.dump

# Restore the filestore to the staging data directory
mkdir -p /opt/odoo-staging/.local/share/Odoo/filestore/
tar xzf /tmp/odoo17_filestore.tar.gz \
  -C /opt/odoo-staging/.local/share/Odoo/filestore/ \
  --strip-components=6

# Start Odoo 19 against the staging database
/opt/odoo19/venv/bin/python /opt/odoo19/odoo/odoo-bin \
  -c /etc/odoo/odoo-staging.conf \
  -d production_v19_staging \
  --update all \
  --stop-after-init

# Check the migration log for errors
grep -E "ERROR|WARNING|CRITICAL" /var/log/odoo/staging.log \
  | grep -v "already exists" | head -50

import logging
from odoo import api, SUPERUSER_ID

_logger = logging.getLogger(__name__)


def migrate(cr, version):
    """Pre-migration: Rename deprecated columns before ORM loads."""
    if not version:
        return

    _logger.info("Starting pre-migration for custom_warehouse module")

    # 1. Rename columns that changed in v18/v19
    cr.execute("""
        ALTER TABLE stock_picking
        RENAME COLUMN x_custom_ref TO x_legacy_ref;
    """)

    # 2. Back up custom computed data before ORM recalculates
    cr.execute("""
        CREATE TABLE IF NOT EXISTS _backup_custom_margins AS
        SELECT id, x_margin_pct, x_landed_cost, write_date
        FROM sale_order_line
        WHERE x_margin_pct IS NOT NULL;
    """)
    _logger.info(
        "Backed up %d margin records", cr.rowcount
    )

    # 3. Update privilege references (v19 breaking change)
    cr.execute("""
        UPDATE ir_model_access
        SET privilege_id = (
            SELECT id FROM res_privilege
            WHERE name = 'Warehouse / Manager'
        )
        WHERE group_id IN (
            SELECT id FROM res_groups
            WHERE full_name LIKE '%%stock.group_stock_manager%%'
        )
        AND privilege_id IS NULL;
    """)
    _logger.info("Migrated %d access rules to privilege_id", cr.rowcount)

-- 1. Check for orphaned ir.model.access records
SELECT imd.module, ima.name, ima.model_id
FROM ir_model_access ima
LEFT JOIN ir_model_data imd ON imd.res_id = ima.id
  AND imd.model = 'ir.model.access'
WHERE ima.privilege_id IS NULL
  AND ima.group_id IS NOT NULL;

-- 2. Verify stock reference migration completeness
SELECT sm.id, sm.reference, sr.name AS new_ref
FROM stock_move sm
LEFT JOIN stock_reference sr ON sr.move_id = sm.id
WHERE sm.reference IS NOT NULL
  AND sr.id IS NULL
LIMIT 20;

-- 3. Check computed field consistency (margin example)
SELECT sol.id,
       sol.x_margin_pct AS current_val,
       bkp.x_margin_pct AS pre_migration_val,
       ABS(sol.x_margin_pct - bkp.x_margin_pct) AS drift
FROM sale_order_line sol
JOIN _backup_custom_margins bkp ON bkp.id = sol.id
WHERE ABS(sol.x_margin_pct - bkp.x_margin_pct) > 0.01
ORDER BY drift DESC
LIMIT 20;

-- 4. Verify filestore attachment integrity
SELECT COUNT(*) AS total_attachments,
       COUNT(store_fname) AS with_filestore,
       COUNT(*) - COUNT(store_fname) AS db_stored
FROM ir_attachment
WHERE res_model IS NOT NULL;