如何从 Rake 任务中知道数据库是否存在 [英] How to know if DB exists from within Rake task

问题描述

如何从 rake 任务中找出数据库是否存在?

How do i find out if the database exists from within a rake task?

也就是说，我想做类似的事情:

that is, i'd like to do something like:

  task :drop_and_create => :environment do
    Rails.env = "development"
    if (db_exists?)
      Rake::Task["db:drop"].invoke
    end
    Rake::Task["db:create"].invoke
    #more stuff...
  end

我如何编写 db_exists?条件?

how do i write the db_exists? condition?

推荐答案

不如做一个开始/救援:

How about instead doing a begin/rescue:

task :drop_and_create => :environment do
    Rails.env = "development"
    if (db_exists?)
    begin
      Rake::Task["db:drop"].invoke

    rescue Exception => e
      logger.debug("Error:#{e}")
    Rake::Task["db:create"].invoke
    #more stuff...
  end

这篇关于如何从 Rake 任务中知道数据库是否存在的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！