created_at and updated_at can't be null
created_at and updated_at can't be null

k0kubun/github-ranking,k0kubun/github-ranking,k0kubun/github-ranking,k0kubun/githubranking,k0kubun/githubranking,k0kubun/github-ranking,k0kubun/githubranking,k0kubun/githubranking,k0kubun/githubranking,k0kubun/github-ranking