SQLWorkbench/docs/PHASE67-DATA-SYNCHRONISATION.md

Phase 67 — Safe missing-row synchronisation preview

From Compare Table Data…, choose source, target, and a shared base table, then select Preview Missing-Row Sync….

The generated INSERT INTO ... SELECT ... WHERE NOT EXISTS statement only proposes insertion of rows whose primary key is absent in the target. It does not update differing records or delete target records. DBSyn does not execute the preview: the user must explicitly copy and review it.

Safeguards and limitations

• Requires matching introspected column names, order, types, nullability, and primary key columns on both sides.
• SQL identifiers are backtick-escaped. Works only on the same MySQL server/connection.
• SQL may still fail due to foreign keys, triggers, generated columns, permissions, incompatible constraints, or concurrent writes. Inspect and adapt SQL before execution.
• The existing Phase 66 comparison remains limited to unordered 500-row samples and must not be treated as a complete diff.
• No automated conflict resolution, deletion, or update is implemented.
• Refresh introspection immediately before generating a preview; take a backup before applying any SQL.