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Class: ActiveRecord::StatementCache

Do not use. This class is for internal use only.
Relationships & Source Files
Namespace Children
Classes:
BindMap, Params, PartialQuery, PartialQueryCollector, Query, Substitute
Inherits: Object
Defined in: activerecord/lib/active_record/statement_cache.rb

Overview

Statement cache is used to cache a single statement in order to avoid creating the AST again. Initializing the cache is done by passing the statement in the create block:

cache = StatementCache.create(ClothingItem.lease_connection) do |params|
  Book.where(name: "my book").where("author_id > 3")
end

The cached statement is executed by using the connection.execute method:

cache.execute([], ClothingItem.lease_connection)

The relation returned by the block is cached, and for each execute call the cached relation gets duped. Database is queried when to_a is called on the relation.

If you want to cache the statement without the values you can use the bind method of the block parameter.

cache = StatementCache.create(ClothingItem.lease_connection) do |params|
  Book.where(name: params.bind)
end

And pass the bind values as the first argument of #execute call.

cache.execute(["my book"], ClothingItem.lease_connection)

Class Method Summary

Instance Method Summary

Constructor Details

.new(query_builder, bind_map, model) ⇒ StatementCache

[ GitHub ] 

  


# File 'activerecord/lib/active_record/statement_cache.rb', line 139



def initialize(query_builder, bind_map, model)
  @query_builder = query_builder
  @bind_map = bind_map
  @model = model
end


  







Class Method Details



  

    .create(connection, callable = nil, &block)  
  

  [ GitHub ]


  

  


# File 'activerecord/lib/active_record/statement_cache.rb', line 132



def self.create(connection, callable = nil, &block)
  relation = (callable || block).call Params.new
  query_builder, binds = connection.cacheable_query(self, relation.arel)
  bind_map = BindMap.new(binds)
  new(query_builder, bind_map, relation.model)
end


  








  

    .partial_query(values)  
  

  [ GitHub ]


  

  


# File 'activerecord/lib/active_record/statement_cache.rb', line 101



def self.partial_query(values)
  PartialQuery.new(values)
end


  








  

    .partial_query_collector  
  

  [ GitHub ]


  

  


# File 'activerecord/lib/active_record/statement_cache.rb', line 105



def self.partial_query_collector
  PartialQueryCollector.new
end


  








  

    .query(sql)  
  

  [ GitHub ]


  

  


# File 'activerecord/lib/active_record/statement_cache.rb', line 97



def self.query(sql)
  Query.new(sql)
end


  








  

    .unsupported_value?(value)  ⇒ Boolean 
  



  

    
  





  


  [ GitHub ]


  

  


# File 'activerecord/lib/active_record/statement_cache.rb', line 158



def self.unsupported_value?(value)
  case value
  when NilClass, Array, Range, Hash, Relation, Base then true
  end
end


  







Instance Method Details



  

    #execute(params, connection, allow_retry: false, async: false, &block)  
  

  [ GitHub ]


  

  


# File 'activerecord/lib/active_record/statement_cache.rb', line 145



def execute(params, connection, allow_retry: false, async: false, &block)
  bind_values = @bind_map.bind params
  sql = @query_builder.sql_for bind_values, connection

  if async
    @model.async_find_by_sql(sql, bind_values, preparable: true, allow_retry: allow_retry, &block)
  else
    @model.find_by_sql(sql, bind_values, preparable: true, allow_retry: allow_retry, &block)
  end
rescue ::RangeError
  async ? Promise.wrap([]) : []
end