-- Script to fix NULL user_name values in activities table
-- This will populate user_name from the users table based on user_id

-- First, let's see how many records have NULL user_name
SELECT COUNT(*) as null_username_count
FROM activities
WHERE user_name IS NULL AND user_id IS NOT NULL;

-- Update activities with user names from users table
UPDATE activities a
SET user_name = u.display_name
FROM users u
WHERE a.user_id = u.user_id
  AND a.user_name IS NULL
  AND u.display_name IS NOT NULL;

-- For users without display_name, use email
UPDATE activities a
SET user_name = u.email
FROM users u
WHERE a.user_id = u.user_id
  AND a.user_name IS NULL
  AND u.email IS NOT NULL;

-- Verify the update
SELECT 
  COUNT(*) as total_activities,
  COUNT(CASE WHEN user_name IS NULL THEN 1 END) as null_usernames,
  COUNT(CASE WHEN user_name IS NOT NULL THEN 1 END) as populated_usernames
FROM activities;

-- Show sample of fixed records
SELECT 
  activity_id,
  user_id,
  user_name,
  activity_type,
  activity_description,
  created_at
FROM activities
ORDER BY created_at DESC
LIMIT 10;