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Class: ActiveRecord::Result

Relationships & Source Files
Super Chains via Extension / Inclusion / Inheritance
Instance Chain:
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_a
# => [{"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

Constant Summary

Class Method Summary

Instance Attribute Summary

::Enumerable - Included

#many?

Returns true if the enumerable has more than 1 element.

Instance Method Summary

::Enumerable - Included

#compact_blank

Returns a new ::Array without the blank items.

#exclude?

The negative of the Enumerable#include?.

#excluding

Returns a copy of the enumerable excluding the specified elements.

#in_order_of

Returns a new ::Array where the order has been set to that provided in the series, based on the key of the objects in the original enumerable.

#including

Returns a new array that includes the passed elements.

#index_by

Convert an enumerable to a hash, using the block result as the key and the element as the value.

#index_with

Convert an enumerable to a hash, using the element as the key and the block result as the value.

#maximum

Calculates the maximum from the extracted elements.

#minimum

Calculates the minimum from the extracted elements.

#pick

Extract the given key from the first element in the enumerable.

#pluck

Extract the given key from each element in the enumerable.

#sole

Returns the sole item in the enumerable.

#without

Constructor Details

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

[ GitHub ]

  
# File 'activerecord/lib/active_record/result.rb', line 49

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 39

attr_reader :columns, :rows, :column_types

#columns (readonly)

[ GitHub ]

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

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 79

def empty?
  rows.empty?
end

#rows (readonly)

[ GitHub ]

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

attr_reader :columns, :rows, :column_types

Instance Method Details

#[](idx)

[ GitHub ]

  
# File 'activerecord/lib/active_record/result.rb', line 90

def [](idx)
  hash_rows[idx]
end

#each(&block)

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 70

def each(&block)
  if block_given?
    hash_rows.each(&block)
  else
    hash_rows.to_enum { @rows.size }
  end
end

#includes_column?(name) ⇒ Boolean

Returns true if this result set includes the column named name

[ GitHub ]

  
# File 'activerecord/lib/active_record/result.rb', line 57

def includes_column?(name)
  @columns.include? name
end

#initialize_copy(other)

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# File 'activerecord/lib/active_record/result.rb', line 133

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

#last(n = nil)

Returns the last record from the rows collection.

[ GitHub ]

  
# File 'activerecord/lib/active_record/result.rb', line 95

def last(n = nil)
  n ? hash_rows.last(n) : hash_rows.last
end

#length

Returns the number of elements in the rows array.

[ GitHub ]

  
# File 'activerecord/lib/active_record/result.rb', line 62

def length
  @rows.length
end

#to_a

Alias for #to_ary.

[ GitHub ]

  
# File 'activerecord/lib/active_record/result.rb', line 88

alias :to_a :to_ary

#to_ary Also known as: #to_a

Returns an array of hashes representing each row record.

[ GitHub ]

  
# File 'activerecord/lib/active_record/result.rb', line 84

def to_ary
  hash_rows
end