Supabase Migration Writer

Supabase Migration Writer

Capabilities

• Generate SQL migration files with proper structure
• Create tables with appropriate RLS policies
• Add indexes for performance
• Document schema changes in API docs
• Handle data type selection and constraints

Migration File Structure

Naming Convention

YYYYMMDDHHMMSS_description.sql

Example: 20250124120000_add_user_notes_table.sql

Location

supabase/​migrations/

Usage Examples

Example 1: Create New Table Migration

User: "Create a migration for user_notes table to store Bible study notes"

Assistant:

-- Migration: 20250124120000_add_user_notes_table.sql

-- Create user_notes table
CREATE TABLE IF NOT EXISTS public.user_notes (
  id UUID PRIMARY KEY DEFAULT gen_random_uuid(),
  user_id UUID NOT NULL REFERENCES auth.users(id) ON DELETE CASCADE,
  verse_id UUID REFERENCES bible_schema.verses(id) ON DELETE CASCADE,
  osis TEXT,
  note_text TEXT NOT NULL,
  tags TEXT[] DEFAULT '{}',
  is_private BOOLEAN DEFAULT true,
  created_at TIMESTAMPTZ DEFAULT now(),
  updated_at TIMESTAMPTZ DEFAULT now()
);

-- Add indexes for performance
CREATE INDEX idx_user_notes_user_id ON public.user_notes(user_id);
CREATE INDEX idx_user_notes_verse_id ON public.user_notes(verse_id);
CREATE INDEX idx_user_notes_created_at ON public.user_notes(created_at DESC);
CREATE INDEX idx_user_notes_tags ON public.user_notes USING GIN(tags);

-- Enable RLS
ALTER TABLE public.user_notes ENABLE ROW LEVEL SECURITY;

-- RLS Policies
CREATE POLICY "Users can view own notes"
ON public.user_notes
FOR SELECT
TO authenticated
USING (user_id = auth.uid());

CREATE POLICY "Users can insert own notes"
ON public.user_notes
FOR INSERT
TO authenticated
WITH CHECK (user_id = auth.uid());

CREATE POLICY "Users can update own notes"
ON public.user_notes
FOR UPDATE
TO authenticated
USING (user_id = auth.uid())
WITH CHECK (user_id = auth.uid());

CREATE POLICY "Users can delete own notes"
ON public.user_notes
FOR DELETE
TO authenticated
USING (user_id = auth.uid());

-- Trigger for updated_at
CREATE TRIGGER set_updated_at
BEFORE UPDATE ON public.user_notes
FOR EACH ROW
EXECUTE FUNCTION public.handle_updated_at();

-- Comments for documentation
COMMENT ON TABLE public.user_notes IS 'User-created Bible study notes';
COMMENT ON COLUMN public.user_notes.verse_id IS 'Optional reference to specific verse';
COMMENT ON COLUMN public.user_notes.osis IS 'OSIS reference for the note';
COMMENT ON COLUMN public.user_notes.is_private IS 'Whether note is private or shareable';

Example 2: Add Column Migration

User: "Add a 'color' column to highlights table"

Assistant:

-- Migration: 20250124121500_add_color_to_highlights.sql

-- Add color column with default
ALTER TABLE public.highlights
ADD COLUMN IF NOT EXISTS color TEXT DEFAULT 'yellow'
CHECK (color IN ('yellow', 'green', 'blue', 'pink', 'orange'));

-- Add index if color will be filtered
CREATE INDEX IF NOT EXISTS idx_highlights_color
ON public.highlights(color);

-- Update comment
COMMENT ON COLUMN public.highlights.color IS 'Highlight color: yellow, green, blue, pink, or orange';

-- Backfill existing rows if needed
UPDATE public.highlights
SET color = 'yellow'
WHERE color IS NULL;

Example 3: Create RPC Function Migration

User: "Create RPC function to get user's recent notes"

Assistant:

-- Migration: 20250124122000_add_get_user_recent_notes_function.sql

CREATE OR REPLACE FUNCTION public.get_user_recent_notes(
  p_user_id UUID DEFAULT auth.uid(),
  p_limit INT DEFAULT 20
)
RETURNS TABLE (
  note_id UUID,
  verse_id UUID,
  osis TEXT,
  note_text TEXT,
  tags TEXT[],
  created_at TIMESTAMPTZ,
  verse_text TEXT,
  book_name TEXT,
  chapter_number INT,
  verse_number INT
)
LANGUAGE sql
STABLE
SECURITY DEFINER
SET search_path TO 'public', 'bible_schema'
AS $$
  SELECT
    n.id AS note_id,
    n.verse_id,
    n.osis,
    n.note_text,
    n.tags,
    n.created_at,
    v.text AS verse_text,
    b.name_fi AS book_name,
    v.chapter_number,
    v.verse_number
  FROM user_notes n
  LEFT JOIN bible_schema.verses v ON n.verse_id = v.id
  LEFT JOIN bible_schema.books b ON v.book_id = b.id
  WHERE n.user_id = p_user_id
  ORDER BY n.created_at DESC
  LIMIT p_limit;
$$;

-- Grant execute permission
GRANT EXECUTE ON FUNCTION public.get_user_recent_notes TO authenticated;

-- Add comment
COMMENT ON FUNCTION public.get_user_recent_notes IS
'Get recent Bible study notes for a user with verse context';

Example 4: Create Index Migration

User: "Add search index to user_notes.note_text"

Assistant:

-- Migration: 20250124123000_add_search_index_to_notes.sql

-- Add search vector column
ALTER TABLE public.user_notes
ADD COLUMN IF NOT EXISTS search_tsv tsvector;

-- Create function to update search vector
CREATE OR REPLACE FUNCTION public.user_notes_search_tsv_trigger()
RETURNS trigger
LANGUAGE plpgsql
AS $$
BEGIN
  NEW.search_tsv := to_tsvector('finnish', coalesce(NEW.note_text, ''));
  RETURN NEW;
END;
$$;

-- Create trigger
CREATE TRIGGER user_notes_search_tsv_update
BEFORE INSERT OR UPDATE ON public.user_notes
FOR EACH ROW
EXECUTE FUNCTION public.user_notes_search_tsv_trigger();

-- Backfill existing rows
UPDATE public.user_notes
SET search_tsv = to_tsvector('finnish', note_text);

-- Create GIN index for fast search
CREATE INDEX idx_user_notes_search_tsv
ON public.user_notes USING GIN(search_tsv);

-- Create search function
CREATE OR REPLACE FUNCTION public.search_user_notes(
  p_query TEXT,
  p_user_id UUID DEFAULT auth.uid(),
  p_limit INT DEFAULT 50
)
RETURNS TABLE (
  note_id UUID,
  note_text TEXT,
  osis TEXT,
  created_at TIMESTAMPTZ,
  rank REAL
)
LANGUAGE sql
STABLE
AS $$
  SELECT
    id,
    note_text,
    osis,
    created_at,
    ts_rank(search_tsv, websearch_to_tsquery('finnish', p_query)) AS rank
  FROM user_notes
  WHERE user_id = p_user_id
    AND search_tsv @@ websearch_to_tsquery('finnish', p_query)
  ORDER BY rank DESC, created_at DESC
  LIMIT p_limit;
$$;

Example 5: Rollback Migration

User: "Create rollback for user_notes table"

Assistant:

-- Migration: 20250124124000_rollback_user_notes.sql

-- Drop RLS policies
DROP POLICY IF EXISTS "Users can delete own notes" ON public.user_notes;
DROP POLICY IF EXISTS "Users can update own notes" ON public.user_notes;
DROP POLICY IF EXISTS "Users can insert own notes" ON public.user_notes;
DROP POLICY IF EXISTS "Users can view own notes" ON public.user_notes;

-- Drop triggers
DROP TRIGGER IF EXISTS set_updated_at ON public.user_notes;

-- Drop indexes
DROP INDEX IF EXISTS idx_user_notes_tags;
DROP INDEX IF EXISTS idx_user_notes_created_at;
DROP INDEX IF EXISTS idx_user_notes_verse_id;
DROP INDEX IF EXISTS idx_user_notes_user_id;

-- Drop table
DROP TABLE IF EXISTS public.user_notes;

Migration Best Practices

1. Use IF NOT EXISTS / IF EXISTS

CREATE TABLE IF NOT EXISTS table_name (...);
DROP TABLE IF EXISTS table_name;
ALTER TABLE table_name ADD COLUMN IF NOT EXISTS column_name type;

2. Add Timestamps

created_at TIMESTAMPTZ DEFAULT now(),
updated_at TIMESTAMPTZ DEFAULT now()

3. Foreign Key Constraints

user_id UUID NOT NULL REFERENCES auth.users(id) ON DELETE CASCADE
verse_id UUID REFERENCES bible_schema.verses(id) ON DELETE SET NULL

4. Indexes for Performance

-- Foreign keys
CREATE INDEX idx_table_user_id ON table_name(user_id);

-- Frequently filtered columns
CREATE INDEX idx_table_status ON table_name(status);

-- Timestamp queries
CREATE INDEX idx_table_created_at ON table_name(created_at DESC);

-- Full-text search
CREATE INDEX idx_table_search ON table_name USING GIN(search_tsv);

-- Array columns
CREATE INDEX idx_table_tags ON table_name USING GIN(tags);

5. Data Types

6. Constraints

-- Not null
column_name TEXT NOT NULL

-- Unique
email TEXT UNIQUE

-- Check
age INT CHECK (age >= 0)

-- Default
status TEXT DEFAULT 'active'

-- Composite unique
UNIQUE(user_id, verse_id)

7. Comments

COMMENT ON TABLE table_name IS 'Description of table purpose';
COMMENT ON COLUMN table_name.column_name IS 'Description of column';

8. RLS Always

ALTER TABLE table_name ENABLE ROW LEVEL SECURITY;

9. Updated At Trigger

CREATE TRIGGER set_updated_at
BEFORE UPDATE ON table_name
FOR EACH ROW
EXECUTE FUNCTION public.handle_updated_at();

10. Security Definer for Functions

CREATE FUNCTION function_name(...)
LANGUAGE sql
SECURITY DEFINER
SET search_path TO 'public'
AS $$...$$;

Schema Selection

Testing Migrations

Local Testing

# Apply migration
supabase db push

# Reset and reapply
supabase db reset

Production Deployment

• Migrations auto-deploy via Lovable Cloud
• Test in dev environment first
• Review migration in Supabase Dashboard

Documentation Updates

After creating migration, update:

1. Docs/​03-API.md - Add new tables/​functions
2. Docs/​02-DESIGN.md - Update architecture if needed
3. CLAUDE.MD - Update schema reference if major change

Advanced PostgreSQL Features

For advanced PostgreSQL-specific guidance, you can leverage the pg-aiguide plugin with these specialized skills:

Available PostgreSQL Skills

1. pg:design-postgres-tables

   • Comprehensive PostgreSQL-specific table design reference
   • Data types, indexing strategies, constraints
   • Performance patterns and best practices
   • Advanced features (partitioning, triggers, etc.)

2. pg:setup-timescaledb-hypertables

   • Design and set up TimescaleDB hypertables
   • Configure compression, retention policies
   • Set up continuous aggregates for time-series data
   • Optimal partition and chunk configuration

3. pg:find-hypertable-candidates

   • Analyze existing tables for TimescaleDB conversion
   • Identify time-series data patterns
   • Evaluate performance improvement opportunities

4. pg:migrate-postgres-tables-to-hypertables

   • Step-by-step migration to TimescaleDB
   • Zero-downtime migration strategies
   • Performance validation and optimization

When to Use pg-aiguide

• Complex indexing requirements - Multi-column indexes, partial indexes, expression indexes
• Time-series data - Bible reading analytics, usage logs, AI usage tracking
• Performance optimization - Query planning, index selection, partition strategies
• Advanced data types - Arrays, JSONB, full-text search, geometric types
• PostgreSQL-specific features - CTEs, window functions, materialized views

Example Usage

// If you need help with table design or time-series optimization:
// Invoke: /​pg:design-postgres-tables
// Or: /​pg:setup-timescaledb-hypertables

// For example, optimizing ai_usage_logs as a hypertable:
// 1. Use pg:find-hypertable-candidates to analyze ai_usage_logs
// 2. Use pg:setup-timescaledb-hypertables to configure optimal settings
// 3. Use pg:migrate-postgres-tables-to-hypertables for migration

Related Documentation

• See Docs/​03-API.md for current schema
• See Docs/​02-DESIGN.md for architecture
• See Docs/​04-DEV-WORKFLOW.md for deployment process