class ActiveRecord::Result

Active Record Result

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

result = ActiveRecord::Base.lease_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

Constants

EMPTY
EMPTY_ASYNC
EMPTY_HASH

Attributes

column_types [R]

columns [R]

rows [R]

Public Class Methods

new (columns, rows, column_types = nil)

Source

# File lib/active_record/result.rb, line 102
def initialize(columns, rows, column_types = nil)
  # We freeze the strings to prevent them getting duped when
  # used as keys in ActiveRecord::Base's @attributes hash
  @columns      = columns.each(&:-@).freeze
  @rows         = rows
  @hash_rows    = nil
  @column_types = column_types || EMPTY_HASH
  @column_indexes = nil
end

Public Instance Methods

[] (idx)

Source

# File lib/active_record/result.rb, line 148
def [](idx)
  hash_rows[idx]
end

each (&block)

Source

# File lib/active_record/result.rb, line 128
def each(&block)
  if block_given?
    hash_rows.each(&block)
  else
    hash_rows.to_enum { @rows.size }
  end
end

Calls the given block once for each element in row collection, passing row as parameter. Each row is a Hash-like, read only object.

To get real hashes, use .to_a.each.

Returns an Enumerator if no block is given.

empty? ()

Source

# File lib/active_record/result.rb, line 137
def empty?
  rows.empty?
end

Returns true if there are no records, otherwise false.

includes_column? (name)

Source

# File lib/active_record/result.rb, line 113
def includes_column?(name)
  @columns.include? name
end

Returns true if this result set includes the column named name

initialize_copy (other)

Source

# File lib/active_record/result.rb, line 191
def initialize_copy(other)
  @rows = rows.dup
  @column_types = column_types.dup
  @hash_rows    = nil
end

last (n = nil)

Source

# File lib/active_record/result.rb, line 153
def last(n = nil)
  n ? hash_rows.last(n) : hash_rows.last
end

Returns the last record from the rows collection.

length ()

Source

# File lib/active_record/result.rb, line 118
def length
  @rows.length
end

Returns the number of elements in the rows array.

to_a ()

Alias for: to_ary

to_ary ()

Source

# File lib/active_record/result.rb, line 142
def to_ary
  hash_rows
end

Returns an array of hashes representing each row record.

Also aliased as: to_a

Private Instance Methods

column_type (name, index, type_overrides)

Source

# File lib/active_record/result.rb, line 224
def column_type(name, index, type_overrides)
  type_overrides.fetch(name) do
    column_types.fetch(index) do
      column_types.fetch(name, Type.default_value)
    end
  end
end

hash_rows ()

Source

# File lib/active_record/result.rb, line 232
def hash_rows
  # We use transform_values to rows.
  # This is faster because we avoid any reallocs and avoid hashing entirely.
  @hash_rows ||= @rows.map do |row|
    column_indexes.transform_values { |index| row[index] }
  end
end