我尝试运行迁移以删除数据库中的两行。这是迁移文件...
class RemoveMenuItem < ActiveRecord::Migration
def up
MenuItem.delete(name: "Validation Settings")
MenuItem.delete(name: "Identifier Lookup")
end
def down
MenuItem.create(name: "Validation Settings", type: "MenuItem", actionable_item_id: 89, actionable_items_count: 0, sequence: 20)
MenuItem.create(name: "Identifier Lookup", type: "MenuItem", actionable_item_id: 89, actionable_items_count: 0, sequence: 30)
end
end
......但是我收到了这个错误...
PG::UndefinedTable: ERROR: missing FROM-clause entry for table "id"
LINE 1: ...ERE "actionable_items"."type" IN ('MenuItem') AND "id"."name...
^
: DELETE FROM "actionable_items" WHERE "actionable_items"."type" IN ('MenuItem') AND "id"."name" = 'Validation Settings'/Users/kweihe/.rvm/gems/ruby-2.1.6/gems/activerecord-3.2.22/lib/active_record/connection_adapters/postgresql_adapter.rb:1163:in `async_exec'
答案 0 :(得分:2)
删除需要已识别的记录才能生效。试试这个:
def up
MenuItem.find_by(name: "Validation Settings").delete
....
我同意评论者的意见 - 这似乎不是您在迁移中必然要做的事情。在种子文件中可能更好。
答案 1 :(得分:0)
<强>解强>
class RemoveActionableItems < ActiveRecord::Migration
class ActionableItem < ActiveRecord::Base
attr_accessible :actionable_item, :name, :sequence, :type
end
def up
validation_settings = MenuItem.find_by_name("Validation Settings")
identifier_lookup = MenuItem.find_by_name("Identifier Lookup")
compliance = InsightReportMenuItem.find_by_name("Compliance")
validation_settings.delete unless validation_settings.nil?
identifier_lookup.delete unless identifier_lookup.nil?
compliance.delete unless compliance.nil?
end
def down
MenuItem.create :name => "Validation Settings", :type => "MenuItem"
MenuItem.create :name => "Identifier Lookup", :type => "MenuItem"
InsightReportMenuItem.create :name => "Compliance", :type => "InsightReportMenuItem"
end
end