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name: database-engineer description: Database schema, migrations ve data integrity için kullanılır. Supabase, PostgreSQL, migration yönetimi ve query optimization konularında uzman.

Database Engineer Skill

Database schema, migrations ve data integrity.

When to Use

• Database schema tasarımı yaparken
• Migration yazarken veya düzenlerken
• Database optimization yaparken
• Data integrity constraints eklerken
• Backup ve restore stratejileri oluştururken
• Data seeding yaparken
• Query optimization yaparken
• Supabase RLS policies yazarken

Instructions

Görevler

• Database schema design
• Migration management (raw SQL)
• Database optimization
• Data integrity constraints
• Backup ve restore strategies
• Data seeding
• Query optimization
• Supabase RLS policies

Kurallar

• Database changes migration ile
• Foreign key constraints kullan
• Indexing slow query'ler için
• Data validation database level
• Backup strategy automated
• Migration rollback plan
• RLS policies tüm tablolar için

Dosya Yapısı

Copysupabase/
├── migrations/
│   ├── 20251222_add_beneficiary_relations.sql
│   ├── 20251224_add_documents_table.sql
│   ├── 20251225_change_ids_to_bigint.sql
│   └── ...
├── schema.sql
└── seed.sql

Migration Example

Copy-- Migration: Add audit logging triggers
-- Created: 2026-01-13

-- Create audit_logs table
CREATE TABLE IF NOT EXISTS audit_logs (
  id BIGSERIAL PRIMARY KEY,
  table_name TEXT NOT NULL,
  record_id BIGINT NOT NULL,
  action TEXT NOT NULL CHECK (action IN ('INSERT', 'UPDATE', 'DELETE')),
  old_data JSONB,
  new_data JSONB,
  user_id UUID REFERENCES auth.users(id),
  created_at TIMESTAMPTZ DEFAULT NOW()
);

-- Create index for faster queries
CREATE INDEX idx_audit_logs_table_record 
  ON audit_logs(table_name, record_id);
CREATE INDEX idx_audit_logs_created_at 
  ON audit_logs(created_at DESC);

-- Create audit trigger function
CREATE OR REPLACE FUNCTION audit_trigger_func()
RETURNS TRIGGER AS $$
BEGIN
  IF TG_OP = 'INSERT' THEN
    INSERT INTO audit_logs (table_name, record_id, action, new_data, user_id)
    VALUES (TG_TABLE_NAME, NEW.id, TG_OP, to_jsonb(NEW), auth.uid());
    RETURN NEW;
  ELSIF TG_OP = 'UPDATE' THEN
    INSERT INTO audit_logs (table_name, record_id, action, old_data, new_data, user_id)
    VALUES (TG_TABLE_NAME, NEW.id, TG_OP, to_jsonb(OLD), to_jsonb(NEW), auth.uid());
    RETURN NEW;
  ELSIF TG_OP = 'DELETE' THEN
    INSERT INTO audit_logs (table_name, record_id, action, old_data, user_id)
    VALUES (TG_TABLE_NAME, OLD.id, TG_OP, to_jsonb(OLD), auth.uid());
    RETURN OLD;
  END IF;
END;
$$ LANGUAGE plpgsql SECURITY DEFINER;

-- Apply triggers to tables
CREATE TRIGGER members_audit_trigger
  AFTER INSERT OR UPDATE OR DELETE ON members
  FOR EACH ROW EXECUTE FUNCTION audit_trigger_func();

RLS Policy Example

Copy-- Enable RLS
ALTER TABLE members ENABLE ROW LEVEL SECURITY;

-- Policy: Users can read all members
CREATE POLICY "Members are viewable by authenticated users"
  ON members FOR SELECT
  TO authenticated
  USING (true);

-- Policy: Only admins can insert
CREATE POLICY "Only admins can insert members"
  ON members FOR INSERT
  TO authenticated
  WITH CHECK (
    EXISTS (
      SELECT 1 FROM user_roles
      WHERE user_id = auth.uid()
      AND role IN ('admin', 'editor')
    )
  );

-- Policy: Only admins can update
CREATE POLICY "Only admins can update members"
  ON members FOR UPDATE
  TO authenticated
  USING (
    EXISTS (
      SELECT 1 FROM user_roles
      WHERE user_id = auth.uid()
      AND role IN ('admin', 'editor')
    )
  );

-- Policy: Only admins can delete
CREATE POLICY "Only admins can delete members"
  ON members FOR DELETE
  TO authenticated
  USING (
    EXISTS (
      SELECT 1 FROM user_roles
      WHERE user_id = auth.uid()
      AND role = 'admin'
    )
  );

Query Optimization Example

Copy-- Before: Slow query without index
SELECT * FROM donations 
WHERE member_id = 123 
ORDER BY created_at DESC;

-- Add index for optimization
CREATE INDEX idx_donations_member_created 
  ON donations(member_id, created_at DESC);

-- Use EXPLAIN ANALYZE to verify
EXPLAIN ANALYZE
SELECT * FROM donations 
WHERE member_id = 123 
ORDER BY created_at DESC;

Seed Data Example

Copy-- Seed initial data
INSERT INTO settings (key, value, description) VALUES
  ('organization_name', 'KafkasDer', 'Organizasyon adı'),
  ('currency', 'TRY', 'Para birimi'),
  ('timezone', 'Europe/Istanbul', 'Zaman dilimi'),
  ('default_language', 'tr', 'Varsayılan dil')
ON CONFLICT (key) DO NOTHING;

-- Seed sample members for development
INSERT INTO members (name, email, phone, status) VALUES
  ('Ahmet Yılmaz', 'ahmet@example.com', '+905551234567', 'active'),
  ('Mehmet Kaya', 'mehmet@example.com', '+905557654321', 'active'),
  ('Ayşe Demir', 'ayse@example.com', '+905559876543', 'active')
ON CONFLICT DO NOTHING;