ruby-on-rails – 为什么首先使用Capistrano运行db：migrate？

上限生产部署

错误是：

** Invoke deploy:migrate (first_time)
** Invoke deploy:set_rails_env
** Execute deploy:migrate
DEBUG [048f89c6] Running /usr/bin/env if test ! -d /home/deployer_user/apps/ap_production/releases/20140209005208; then echo "Directory does not exist '/home/deployer_user/apps/ap_production/releases/20140209005208'" 1>&2; false; fi on eslope.net
DEBUG [048f89c6] Command: if test ! -d /home/deployer_user/apps/ap_production/releases/20140209005208; then echo "Directory does not exist '/home/deployer_user/apps/ap_production/releases/20140209005208'" 1>&2; false; fi
DEBUG [048f89c6] Finished in 0.160 seconds with exit status 0 (successful).
INFO [52f75214] Running ~/.rbenv/bin/rbenv exec bundle exec rake db:migrate on eserver.net
DEBUG [52f75214] Command: cd /home/deployer_user/apps/ap_production/releases/20140209005208 && ( RBENV_ROOT=~/.rbenv RBENV_VERSION=2.1.0 RAILS_ENV=production ~/.rbenv/bin/rbenv exec bundle exec rake db:migrate )
DEBUG [52f75214]    rake aborted!
DEBUG [52f75214]    An error has occurred,this and all later migrations canceled:
DEBUG [52f75214]    
DEBUG [52f75214]    PG::UndefinedTable: ERROR:  relation "client_infos" does not exist
DEBUG [52f75214]    : ALTER TABLE "client_infos" RENAME TO "clients

这个错误实际上是完全合理的.引用的表不存在.我不明白为什么迁移正在运行？为什么不在第一次运行时从模式创建数据库.我是否无意中删除了一个说明已运行迁移的文件？只是删除它,或“.gitignoring”它？

我想我知道如何解决它(rake db：create或者类似)但是我不明白的是,如果在Capistrano v3它知道它是第一次,为什么它不会直接使用架构而不是运行所有迁移？我是一个菜鸟,这似乎是合理的,但另一方面,运行迁移会获得相同的结果,所以……(但是那些不会盲目地在生产中使用迁移的人们呢？不会他们被卡住？)谢谢.