class ActiveRecord::Result

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

Attributes

column_types[R]
columns[R]
rows[R]

Public Class Methods

new(columns, rows, column_types = {}) click to toggle source
# File lib/active_record/result.rb, line 38
def initialize(columns, rows, column_types = {})
  @columns      = columns
  @rows         = rows
  @hash_rows    = nil
  @column_types = column_types
end

Public Instance Methods

[](idx) click to toggle source
# File lib/active_record/result.rb, line 73
def [](idx)
  hash_rows[idx]
end
each() { |row| ... } click to toggle source
# File lib/active_record/result.rb, line 49
def each
  if block_given?
    hash_rows.each { |row| yield row }
  else
    hash_rows.to_enum { @rows.size }
  end
end
empty?() click to toggle source

Returns true if there are no records.

# File lib/active_record/result.rb, line 65
def empty?
  rows.empty?
end
initialize_copy(other) click to toggle source
# File lib/active_record/result.rb, line 90
def initialize_copy(other)
  @columns      = columns.dup
  @rows         = rows.dup
  @column_types = column_types.dup
  @hash_rows    = nil
end
last() click to toggle source
# File lib/active_record/result.rb, line 77
def last
  hash_rows.last
end
length() click to toggle source
# File lib/active_record/result.rb, line 45
def length
  @rows.length
end
to_ary() click to toggle source
# File lib/active_record/result.rb, line 69
def to_ary
  hash_rows
end
to_hash() click to toggle source
# File lib/active_record/result.rb, line 57
def to_hash
  hash_rows
end

Private Instance Methods

column_type(name, type_overrides = {}) click to toggle source
# File lib/active_record/result.rb, line 99
def column_type(name, type_overrides = {})
  type_overrides.fetch(name) do
    column_types.fetch(name, IDENTITY_TYPE)
  end
end
hash_rows() click to toggle source
# File lib/active_record/result.rb, line 105
def hash_rows
  @hash_rows ||=
    begin
      # We freeze the strings to prevent them getting duped when
      # used as keys in ActiveRecord::Base's @attributes hash
      columns = @columns.map { |c| c.dup.freeze }
      @rows.map { |row|
        # In the past we used Hash[columns.zip(row)]
        #  though elegant, the verbose way is much more efficient
        #  both time and memory wise cause it avoids a big array allocation
        #  this method is called a lot and needs to be micro optimised
        hash = {}

        index = 0
        length = columns.length

        while index < length
          hash[columns[index]] = row[index]
          index += 1
        end

        hash
      }
    end
end