db-migrator

When Invoked

1. Understand the schema change needed
2. Check existing schema and migrations
3. Generate migration SQL
4. Apply and verify

Pre-Migration Checklist

# Check existing schema
ls -la supabase/migrations/ | tail -10
# Check current tables (Supabase MCP)
# Review related migrations for naming patterns

Migration Standards

File Naming

supabase migration new add_user_profiles
# → supabase/migrations/<YYYYMMDDHHMMSS>_add_user_profiles.sql

Let the CLI prefix the 14-digit UTC timestamp so same-day migrations still order correctly; do not hand-write an 8-digit date prefix.

Required Elements for Every Table

-- 1. UUID primary key
CREATE TABLE table_name (
  id UUID PRIMARY KEY DEFAULT gen_random_uuid(),
  
  -- 2. Your columns here
  name TEXT NOT NULL,
  status TEXT NOT NULL DEFAULT 'active',
  
  -- 3. Always include timestamps
  created_at TIMESTAMPTZ NOT NULL DEFAULT now(),
  updated_at TIMESTAMPTZ NOT NULL DEFAULT now()
);

-- 4. Auto-update trigger for updated_at
CREATE TRIGGER set_updated_at
  BEFORE UPDATE ON table_name
  FOR EACH ROW EXECUTE FUNCTION moddatetime(updated_at);

-- 5. Indexes on foreign keys and frequently queried columns
CREATE INDEX idx_table_name_status ON table_name(status);

-- 6. RLS on every table (Supabase exposes tables through PostgREST; without it every row is readable with the anon key)
ALTER TABLE table_name ENABLE ROW LEVEL SECURITY;

-- 7. RLS policies
CREATE POLICY "Users can read own data" ON table_name
  FOR SELECT USING (auth.uid() = user_id);

CREATE POLICY "Users can insert own data" ON table_name
  FOR INSERT WITH CHECK (auth.uid() = user_id);

CREATE POLICY "Users can update own data" ON table_name
  FOR UPDATE USING (auth.uid() = user_id)
  WITH CHECK (auth.uid() = user_id);

Column Type Guide

Data	Use	Don't Use
IDs	UUID	SERIAL, TEXT
Money	DECIMAL(10,2)	FLOAT, REAL
Timestamps	TIMESTAMPTZ	TIMESTAMP
Status/enum	TEXT + CHECK or PG ENUM	Unconstrained TEXT
JSON data	JSONB	JSON, TEXT
Boolean	BOOLEAN	INT, TEXT