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Class: ActiveRecord::Result

Relationships & Source Files
Super Chains via Extension / Inclusion / Inheritance
Instance Chain:
self, ::Enumerable
Inherits: Object
Defined in: activerecord/lib/active_record/result.rb

Overview

This class encapsulates a result returned from calling #exec_query on any database connection adapter. For example:

result = ActiveRecord::Base.connection.exec_query('SELECT id, title, body FROM posts')
result # => #<ActiveRecord::Result:0xdeadbeef>

# Get the column names of the result:
result.columns
# => ["id", "title", "body"]

# Get the record values of the result:
result.rows
# => [[1, "title_1", "body_1"],
      [2, "title_2", "body_2"],
      #...
     ]

# Get an array of hashes representing the result (column => value):
result.to_hash
# => [{"id" => 1, "title" => "title_1", "body" => "body_1"},
      {"id" => 2, "title" => "title_2", "body" => "body_2"},
      #...
     ]

# ActiveRecord::Result also includes Enumerable.
result.each do |row|
  puts row['title'] + " " + row['body']
end

Class Method Summary

Instance Attribute Summary

::Enumerable - Included

#many?

Returns true if the enumerable has more than 1 element.

Instance Method Summary

::Enumerable - Included

#exclude?

The negative of the Enumerable#include?.
#index_by

Convert an enumerable to a hash.
#pluck

Convert an enumerable to an array based on the given key.
#sum

Calculates a sum from the elements.
#without

Returns a copy of the enumerable without the specified elements.

Constructor Details

.new(columns, rows, column_types = {}) ⇒ Result

[ GitHub ] 

  


# File 'activerecord/lib/active_record/result.rb', line 39



def initialize(columns, rows, column_types = {})
  @columns      = columns
  @rows         = rows
  @hash_rows    = nil
  @column_types = column_types
end


  







Instance Attribute Details



  

    #column_types   (readonly)
  

  [ GitHub ]


  

  


# File 'activerecord/lib/active_record/result.rb', line 37



attr_reader :columns, :rows, :column_types


  








  

    #columns   (readonly)
  

  [ GitHub ]


  

  


# File 'activerecord/lib/active_record/result.rb', line 37



attr_reader :columns, :rows, :column_types


  








  

    #empty?  ⇒ Boolean  (readonly)
  



  

    

Returns true if there are no records, otherwise false.


  





  


  [ GitHub ]


  

  


# File 'activerecord/lib/active_record/result.rb', line 72



def empty?
  rows.empty?
end


  








  

    #rows   (readonly)
  

  [ GitHub ]


  

  


# File 'activerecord/lib/active_record/result.rb', line 37



attr_reader :columns, :rows, :column_types


  







Instance Method Details



  

    #[](idx)  
  

  [ GitHub ]


  

  


# File 'activerecord/lib/active_record/result.rb', line 81



def [](idx)
  hash_rows[idx]
end


  








  

    #collect!  
  

  [ GitHub ]


  

  


# File 'activerecord/lib/active_record/result.rb', line 69



alias :collect! :map


  








  

    #each  
  



  

    

Calls the given block once for each element in row collection, passing row as parameter.



Returns an Enumerator if no block is given.


  



  [ GitHub ]


  

  


# File 'activerecord/lib/active_record/result.rb', line 55



def each
  if block_given?
    hash_rows.each { |row| yield row }
  else
    hash_rows.to_enum { @rows.size }
  end
end


  








  

    #first  
  



  

    

Returns the first record from the rows collection. If the rows collection is empty, returns nil.


  



  [ GitHub ]


  

  


# File 'activerecord/lib/active_record/result.rb', line 87



def first
  return nil if @rows.empty?
  Hash[@columns.zip(@rows.first)]
end


  








  

    #initialize_copy(other)  
  

  [ GitHub ]


  

  


# File 'activerecord/lib/active_record/result.rb', line 108



def initialize_copy(other)
  @columns      = columns.dup
  @rows         = rows.dup
  @column_types = column_types.dup
  @hash_rows    = nil
end


  








  

    #last  
  



  

    

Returns the last record from the rows collection. If the rows collection is empty, returns nil.


  



  [ GitHub ]


  

  


# File 'activerecord/lib/active_record/result.rb', line 94



def last
  return nil if @rows.empty?
  Hash[@columns.zip(@rows.last)]
end


  








  

    #length  
  



  

    

Returns the number of elements in the rows array.


  



  [ GitHub ]


  

  


# File 'activerecord/lib/active_record/result.rb', line 47



def length
  @rows.length
end


  








  

    #map!  
  

  [ GitHub ]


  

  


# File 'activerecord/lib/active_record/result.rb', line 68



alias :map! :map


  








  

    #to_ary  
  



  

    

Returns an array of hashes representing each row record.


  



  [ GitHub ]


  

  


# File 'activerecord/lib/active_record/result.rb', line 77



def to_ary
  hash_rows
end


  








  

    #to_hash  
  



  

    

Returns an array of hashes representing each row record.


  



  [ GitHub ]


  

  


# File 'activerecord/lib/active_record/result.rb', line 64



def to_hash
  hash_rows
end