Class: Archon::InsertIntoSelect

Inherits:
Arel::InsertManager
  • Object
show all
Defined in:
lib/archon/insert_into_select.rb

Overview

InsertIntoSelect

Extends an ARel InsertManager that will generate an ‘INSERT INTO (…) SELECT` query, which will insert data into the given table from the given selection - either an ARel SelectManager-ish, or an ActiveRecord::Relation.

It will try to determine the columns that will be inserted from the projections specified in the given selection.

Instance Attribute Summary collapse

Instance Method Summary collapse

Constructor Details

#initialize(tableish, selectish, options = {}) ⇒ InsertIntoSelect

Returns a new instance of InsertIntoSelect.



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# File 'lib/archon/insert_into_select.rb', line 17

def initialize(tableish, selectish, options = {})
  super()
  self.into tableish.respond_to?(:arel_table) ? tableish.arel_table : tableish
  self.select selectish.respond_to?(:arel) ? selectish.arel : selectish

  # Fetch the insert columns from the options - default to the select column names interpolated
  # into the inserted table:
  self.columns.concat options.fetch(
    :columns,
    ast.select.projections.map do |projection|
      column_name = case projection
                    when Arel::Attributes::Attribute
                      projection.name
                    when Arel::Nodes::As
                      projection.right.delete('"').to_sym
                    when Arel::Nodes::NamedFunction
                      projection.alias.delete('"').to_sym
                    when String
                      _table, name = projection.split('.') if projection['.']
                      (name || projection).delete('"').to_sym
                    else
                      raise "Don't know how to..."
                    end
      ast.relation[column_name]
    end
  )
end

Instance Attribute Details

#projections ⇒ Object (readonly)

Returns the value of attribute projections.



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# File 'lib/archon/insert_into_select.rb', line 16

def projections
  @projections
end