使用Ruby closure_tree gem without rails

Question

我想嘗試gem closure_tree爲我的族譜數據庫構建一棵樹。 我在Windows 7盒子上安裝了Ruby MRI 2.3.0下的gem。 依賴關係的版本位於下面的錯誤日誌中。

$ gem install closure_tree 
Fetching: with_advisory_lock-3.0.0.gem (100%) 
Successfully installed with_advisory_lock-3.0.0 
Fetching: closure_tree-6.2.0.gem (100%) 
Successfully installed closure_tree-6.2.0 
2 gems installed 

當我嘗試失敗的最簡約的代碼，我想是因爲我不使用Rails和不這樣做，再次我相信創建表tag_hierachies

我的問題是遷移：能如何使用這個沒有Rails的gem？

require 'active_record' 
require 'closure_tree' 

ActiveRecord::Base.establish_connection(
    :adapter => "sqlite3", 
    :database => "sample.db" 
) 

if !ActiveRecord::Base.connection.table_exists?('tags') 
    ActiveRecord::Schema.define do 
    create_table :tags do |table| 
     table.column :name, :string 
     table.column :parent_id, :integer 
    end 
    end 
end 

class Tag < ActiveRecord::Base 
    has_closure_tree 
end 

grandparent = Tag.create(name: 'Grandparent') 

給

d:/Ruby/lib/ruby/gems/2.3.0/gems/activerecord-4.2.6/lib/active_record/connection_adapters/sqlite3_adapter.rb:513:in `table_structure': Could not find table 'tag_hierarchies' (ActiveRecord::StatementInvalid) 
    from d:/Ruby/lib/ruby/gems/2.3.0/gems/activerecord-4.2.6/lib/active_record/connection_adapters/sqlite3_adapter.rb:387:in `columns' 
    from d:/Ruby/lib/ruby/gems/2.3.0/gems/activerecord-4.2.6/lib/active_record/connection_adapters/schema_cache.rb:43:in `columns' 
    from d:/Ruby/lib/ruby/gems/2.3.0/gems/activerecord-4.2.6/lib/active_record/attributes.rb:93:in `columns' 
    from d:/Ruby/lib/ruby/gems/2.3.0/gems/activerecord-4.2.6/lib/active_record/attributes.rb:98:in `columns_hash' 
    from d:/Ruby/lib/ruby/gems/2.3.0/gems/activerecord-4.2.6/lib/active_record/inheritance.rb:205:in `subclass_from_attributes?' 
    from d:/Ruby/lib/ruby/gems/2.3.0/gems/activerecord-4.2.6/lib/active_record/inheritance.rb:54:in `new' 
    from d:/Ruby/lib/ruby/gems/2.3.0/gems/activerecord-4.2.6/lib/active_record/persistence.rb:50:in `create!' 
    from d:/Ruby/lib/ruby/gems/2.3.0/gems/closure_tree-6.2.0/lib/closure_tree/hierarchy_maintenance.rb:65:in `block in rebuild!' 
    from d:/Ruby/lib/ruby/gems/2.3.0/gems/closure_tree-6.2.0/lib/closure_tree/support.rb:108:in `block (2 levels) in with_advisory_lock' 
    from d:/Ruby/lib/ruby/gems/2.3.0/gems/activerecord-4.2.6/lib/active_record/connection_adapters/abstract/database_statements.rb:211:in `transaction' 
    from d:/Ruby/lib/ruby/gems/2.3.0/gems/activerecord-4.2.6/lib/active_record/transactions.rb:220:in `transaction' 
    from d:/Ruby/lib/ruby/gems/2.3.0/gems/closure_tree-6.2.0/lib/closure_tree/support.rb:108:in `block in with_advisory_lock' 
    from d:/Ruby/lib/ruby/gems/2.3.0/gems/with_advisory_lock-3.0.0/lib/with_advisory_lock/base.rb:77:in `yield_with_lock' 
    from d:/Ruby/lib/ruby/gems/2.3.0/gems/with_advisory_lock-3.0.0/lib/with_advisory_lock/base.rb:65:in `yield_with_lock_and_timeout' 
    from d:/Ruby/lib/ruby/gems/2.3.0/gems/with_advisory_lock-3.0.0/lib/with_advisory_lock/base.rb:48:in `with_advisory_lock_if_needed' 
    from d:/Ruby/lib/ruby/gems/2.3.0/gems/with_advisory_lock-3.0.0/lib/with_advisory_lock/concern.rb:16:in `with_advisory_lock_result' 
    from d:/Ruby/lib/ruby/gems/2.3.0/gems/with_advisory_lock-3.0.0/lib/with_advisory_lock/concern.rb:10:in `with_advisory_lock' 
    from d:/Ruby/lib/ruby/gems/2.3.0/gems/closure_tree-6.2.0/lib/closure_tree/support.rb:107:in `with_advisory_lock' 
    from d:/Ruby/lib/ruby/gems/2.3.0/gems/closure_tree-6.2.0/lib/closure_tree/hierarchy_maintenance.rb:63:in `rebuild!' 
    from d:/Ruby/lib/ruby/gems/2.3.0/gems/closure_tree-6.2.0/lib/closure_tree/hierarchy_maintenance.rb:39:in `_ct_after_save' 
    from d:/Ruby/lib/ruby/gems/2.3.0/gems/activesupport-4.2.6/lib/active_support/callbacks.rb:432:in `block in make_lambda' 
    from d:/Ruby/lib/ruby/gems/2.3.0/gems/activesupport-4.2.6/lib/active_support/callbacks.rb:228:in `block in halting_and_conditional' 
    from d:/Ruby/lib/ruby/gems/2.3.0/gems/activesupport-4.2.6/lib/active_support/callbacks.rb:506:in `block in call' 
    from d:/Ruby/lib/ruby/gems/2.3.0/gems/activesupport-4.2.6/lib/active_support/callbacks.rb:506:in `each' 
    from d:/Ruby/lib/ruby/gems/2.3.0/gems/activesupport-4.2.6/lib/active_support/callbacks.rb:506:in `call' 
    from d:/Ruby/lib/ruby/gems/2.3.0/gems/activesupport-4.2.6/lib/active_support/callbacks.rb:92:in `__run_callbacks__' 
    from d:/Ruby/lib/ruby/gems/2.3.0/gems/activesupport-4.2.6/lib/active_support/callbacks.rb:778:in `_run_save_callbacks' 
    from d:/Ruby/lib/ruby/gems/2.3.0/gems/activerecord-4.2.6/lib/active_record/callbacks.rb:302:in `create_or_update' 
    from d:/Ruby/lib/ruby/gems/2.3.0/gems/activerecord-4.2.6/lib/active_record/persistence.rb:120:in `save' 
    from d:/Ruby/lib/ruby/gems/2.3.0/gems/activerecord-4.2.6/lib/active_record/validations.rb:37:in `save' 
    from d:/Ruby/lib/ruby/gems/2.3.0/gems/activerecord-4.2.6/lib/active_record/attribute_methods/dirty.rb:21:in `save' 
    from d:/Ruby/lib/ruby/gems/2.3.0/gems/activerecord-4.2.6/lib/active_record/transactions.rb:286:in `block (2 levels) in save' 
    from d:/Ruby/lib/ruby/gems/2.3.0/gems/activerecord-4.2.6/lib/active_record/transactions.rb:351:in `block in with_transaction_returning_status' 
    from d:/Ruby/lib/ruby/gems/2.3.0/gems/activerecord-4.2.6/lib/active_record/connection_adapters/abstract/database_statements.rb:213:in `block in transaction' 
    from d:/Ruby/lib/ruby/gems/2.3.0/gems/activerecord-4.2.6/lib/active_record/connection_adapters/abstract/transaction.rb:184:in `within_new_transaction' 
    from d:/Ruby/lib/ruby/gems/2.3.0/gems/activerecord-4.2.6/lib/active_record/connection_adapters/abstract/database_statements.rb:213:in `transaction' 
    from d:/Ruby/lib/ruby/gems/2.3.0/gems/activerecord-4.2.6/lib/active_record/transactions.rb:220:in `transaction' 
    from d:/Ruby/lib/ruby/gems/2.3.0/gems/activerecord-4.2.6/lib/active_record/transactions.rb:348:in `with_transaction_returning_status' 
    from d:/Ruby/lib/ruby/gems/2.3.0/gems/activerecord-4.2.6/lib/active_record/transactions.rb:286:in `block in save' 
    from d:/Ruby/lib/ruby/gems/2.3.0/gems/activerecord-4.2.6/lib/active_record/transactions.rb:301:in `rollback_active_record_state!' 
    from d:/Ruby/lib/ruby/gems/2.3.0/gems/activerecord-4.2.6/lib/active_record/transactions.rb:285:in `save' 
    from d:/Ruby/lib/ruby/gems/2.3.0/gems/activerecord-4.2.6/lib/active_record/persistence.rb:34:in `create' 
    from C:/Users/Gebruiker/BoxSync/ruby_werk/acts_as_tree/closure_tree.rb:22:in `<main>' 

Answer 1

似乎在README的安裝說明在思想集中，只有軌。但它會告訴你，你需要另一個表格（除了當前的tags表格）以及名稱tag_hierarchies。

在Rails中，此表的生成似乎是安裝步驟的一部分;鏈接文檔中的第5步。

因此，您應該創建tag_hierarchies表，其中包含以下內容，這是rails g closure_tree:migration tag就表結構而言所生成的內容。請參閱create_hierarchies_table.rb.erb，因爲您可能還想添加索引，如鏈接文件中所示。

所以，更新腳本按預期爲我工作下列：

require 'active_record'                         
require 'closure_tree'                         

ActiveRecord::Base.establish_connection(                    
    :adapter => "sqlite3",                        
    :database => "sample.db"                       
)                              

if !ActiveRecord::Base.connection.data_source_exists?('tags')               
    ActiveRecord::Schema.define do                      
    create_table :tags do |table|                      
     table.column :name, :string                      
     table.column :parent_id, :integer                     
    end                             
    end                             
end                              

# You also need a corresponding model's table name followed by "_hierarchies" table.         
#                              
# Migration created based on                       
# `https://github.com/mceachen/closure_tree/blob/master/lib/generators/closure_tree/templates/create_hierarchies_table.rb.erb` 
if !ActiveRecord::Base.connection.data_source_exists?(:tag_hierarchies)             
    ActiveRecord::Schema.define do                      
    create_table :tag_hierarchies do |table|                   
     table.integer :ancestor_id, null: false                   
     table.integer :descendant_id, null: false                   
     table.integer :generations, null: false                   
    end                             
    end                             
end                              

class Tag < ActiveRecord::Base                       
    has_closure_tree                          
end                              

grandparent = Tag.create(name: 'Grandparent')                   

grandparent.children.create(name: 'Father')                    
grandparent.children.create(name: 'Uncle')