This directory contains all SQL for the Customer Feedback demo app.

db/
├── install.sql                   # Master orchestrator (called from scripts/deploy.sql)
├── schema/
│   ├── 000_schema_migrations.sql # Migration tracking table (idempotent)
│   └── 001_create_feedback.sql   # cf_feedback table + indexes (idempotent)
└── migrations/
    ├── 002_seed_data.sql         # Sample data (idempotent MERGE)
    └── 003_add_category.sql      # THE DEMO MOMENT: adds category column

1. Numbered prefix on every file (NNN_description.sql). Numbers are sequential, three digits, no gaps. validate.yml enforces this.
2. Idempotent. Every script can be run repeatedly without error:
   • DDL is wrapped in PL/SQL blocks that catch ORA-00955 (object exists) or ORA-01430 (column exists).
   • DML uses MERGE keyed on natural keys.
3. No bare COMMIT at file top — let the master script control transactions when possible. DDL auto-commits regardless.
4. WHENEVER SQLERROR EXIT is configured by the caller (scripts/deploy.sql), so any unhandled error aborts the pipeline.

1. Create the next sequentially-numbered file in db/migrations/.
2. Wrap DDL in BEGIN ... EXCEPTION WHEN OTHERS THEN ... END; with the appropriate SQLCODE check.
3. Add an @@migrations/NNN_xxx.sql line plus its schema_migrations MERGE to db/install.sql.
4. Open a PR. validate.yml will check numbering and idempotency hygiene.