Rails迁移用于修改现有数据库视图

Question

我有一个名为my_view的视图，是通过以下迁移创建的。

class CreateMyView < ActiveRecord::Migration
  def change
    execute <<-SQL
      drop view if exists my_view
    SQL

    execute <<-SQL
      CREATE OR REPLACE VIEW my_view AS 
      SELECT 
        t1.wfs_id,
        t1.step_id,
        t1.status,
        t1.applied_by,
        t2.created_at,
        t2.is_wfs_end,
        t2.app_status AS flowstep
       FROM table1 t1
         JOIN table2 t2 ON t1.wfs_id = t2.wfs_id
      WHERE t1.del_flag = false;
    SQL
  end
end

现在我需要另一个字段，比如table1表中的my_new_field在my_view中可用。但是我不知道如何编写此迁移。非常感谢任何帮助。谢谢。

- Tony Vincent

Answer 1

那么，简单地重新创建这个视图怎么样：

class ChangeMyView < ActiveRecord::Migration   
  def change
    execute <<-SQL
      drop view if exists my_view
    SQL

    execute <<-SQL
      CREATE OR REPLACE VIEW my_view AS 
      SELECT 
        t1.wfs_id,
        t1.step_id,
        t1.status,
        t1.applied_by,
        t1.my_new_field,
        t2.created_at,
        t2.is_wfs_end,
        t2.app_status AS flowstep
      FROM table1 t1
        JOIN table2 t2 ON t1.wfs_id = t2.wfs_id
      WHERE t1.del_flag = false;
   SQL 
  end

end

- irene

Answer 2

Thoughtbot开发的scenic宝石将大大帮助您管理视图！

- François F