STI 或者有 model 继承的情况，初始化会出问题

[bastengao]

执行 rails console 会报下面错，ps: 调用占是从上往下。初步定位是 descends_from_active_record? 方法 STI 检查时 load_schema, 这时数据库还没创建就报错了。

Gem 2.4.1
Rails 5.2.0
Ruby 2.5.0

24: from /Users/basten/.rvm/gems/ruby-2.5.0/gems/second_level_cache-2.4.1/lib/second_level_cache/mixin.rb:17:in `second_level_cache'
 23: from /Users/basten/.rvm/gems/ruby-2.5.0/gems/activerecord-5.2.0/lib/active_record/core.rb:286:in `relation'
 22: from /Users/basten/.rvm/gems/ruby-2.5.0/gems/activerecord-5.2.0/lib/active_record/inheritance.rb:84:in `finder_needs_type_condition?'
 21: from /Users/basten/.rvm/gems/ruby-2.5.0/gems/activerecord-5.2.0/lib/active_record/inheritance.rb:78:in `descends_from_active_record?'
 20: from /Users/basten/.rvm/gems/ruby-2.5.0/gems/activerecord-5.2.0/lib/active_record/model_schema.rb:336:in `columns_hash'
 19: from /Users/basten/.rvm/gems/ruby-2.5.0/gems/activerecord-5.2.0/lib/active_record/model_schema.rb:456:in `load_schema'
 18: from /Users/basten/.rvm/rubies/ruby-2.5.0/lib/ruby/2.5.0/monitor.rb:226:in `mon_synchronize'
 17: from /Users/basten/.rvm/gems/ruby-2.5.0/gems/activerecord-5.2.0/lib/active_record/model_schema.rb:459:in `block in load_schema'
 16: from /Users/basten/.rvm/gems/ruby-2.5.0/gems/activerecord-5.2.0/lib/active_record/attribute_decorators.rb:51:in `load_schema!'
 15: from /Users/basten/.rvm/gems/ruby-2.5.0/gems/activerecord-5.2.0/lib/active_record/attributes.rb:234:in `load_schema!'
 14: from /Users/basten/.rvm/gems/ruby-2.5.0/gems/activerecord-5.2.0/lib/active_record/model_schema.rb:466:in `load_schema!'
 13: from /Users/basten/.rvm/gems/ruby-2.5.0/gems/activerecord-5.2.0/lib/active_record/connection_handling.rb:90:in `connection'
 12: from /Users/basten/.rvm/gems/ruby-2.5.0/gems/activerecord-5.2.0/lib/active_record/connection_handling.rb:118:in `retrieve_connection'
 11: from /Users/basten/.rvm/gems/ruby-2.5.0/gems/activerecord-5.2.0/lib/active_record/connection_adapters/abstract/connection_pool.rb:1008:in `retrieve_connection'
 10: from /Users/basten/.rvm/gems/ruby-2.5.0/gems/activerecord-5.2.0/lib/active_record/connection_adapters/abstract/connection_pool.rb:380:in `connection'
  9: from /Users/basten/.rvm/gems/ruby-2.5.0/gems/activerecord-5.2.0/lib/active_record/connection_adapters/abstract/connection_pool.rb:521:in `checkout'
  8: from /Users/basten/.rvm/gems/ruby-2.5.0/gems/activerecord-5.2.0/lib/active_record/connection_adapters/abstract/connection_pool.rb:793:in `acquire_connection'
  7: from /Users/basten/.rvm/gems/ruby-2.5.0/gems/activerecord-5.2.0/lib/active_record/connection_adapters/abstract/connection_pool.rb:832:in `try_to_checkout_new_connection'
  6: from /Users/basten/.rvm/gems/ruby-2.5.0/gems/activerecord-5.2.0/lib/active_record/connection_adapters/abstract/connection_pool.rb:853:in `checkout_new_connection'
  5: from /Users/basten/.rvm/gems/ruby-2.5.0/gems/activerecord-5.2.0/lib/active_record/connection_adapters/abstract/connection_pool.rb:809:in `new_connection'
  4: from /Users/basten/.rvm/gems/ruby-2.5.0/gems/activerecord-5.2.0/lib/active_record/connection_adapters/postgresql_adapter.rb:40:in `postgresql_connection'
  3: from /Users/basten/.rvm/gems/ruby-2.5.0/gems/activerecord-5.2.0/lib/active_record/connection_adapters/postgresql_adapter.rb:40:in `new'
  2: from /Users/basten/.rvm/gems/ruby-2.5.0/gems/activerecord-5.2.0/lib/active_record/connection_adapters/postgresql_adapter.rb:215:in `initialize'
  1: from /Users/basten/.rvm/gems/ruby-2.5.0/gems/activerecord-5.2.0/lib/active_record/connection_adapters/postgresql_adapter.rb:683:in `connect'
/Users/basten/.rvm/gems/ruby-2.5.0/gems/activerecord-5.2.0/lib/active_record/connection_adapters/postgresql_adapter.rb:688:in `rescue in connect': FATAL:  database "xxx_dev" does not exist (ActiveRecord::NoDatabaseError)