-- ============================================================================
-- Add project_id to users table
-- This allows assigning a specific project to OPERATOR users
-- ADMIN users don't need a project assignment (can see all projects)
-- ============================================================================

-- Add project_id column to users table
ALTER TABLE users 
ADD COLUMN project_id UUID REFERENCES projects(id) ON DELETE SET NULL;

-- Add index for better query performance
CREATE INDEX idx_users_project_id ON users(project_id);

-- Add comment
COMMENT ON COLUMN users.project_id IS 'Assigned project for OPERATOR users. NULL for ADMIN users who can access all projects.';

-- ============================================================================
-- Verify the change
-- ============================================================================
SELECT 
    column_name, 
    data_type, 
    is_nullable,
    column_default
FROM information_schema.columns 
WHERE table_name = 'users' 
  AND column_name = 'project_id';