module ClosureTree::NumericDeterministicOrdering::ClassMethods
Public Instance Methods
_ct_sum_order_by(node = nil)
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If node is nil, order the whole tree.
# File lib/closure_tree/numeric_deterministic_ordering.rb, line 53 def _ct_sum_order_by(node = nil) stats_sql = <<-SQL.squish SELECT count(*) as total_descendants, max(generations) as max_depth FROM #{_ct.quoted_hierarchy_table_name} SQL stats_sql += " WHERE ancestor_id = #{_ct.quote(node.id)}" if node h = _ct.connection.select_one(stats_sql) depth_column = node ? 'depths.generations' : 'depths.max_depth' node_score = "(1 + anc.#{_ct.quoted_order_column(false)}) * " + "power(#{h['total_descendants']}, #{h['max_depth'].to_i + 1} - #{depth_column})" # We want the NULLs to be first in case we are not ordering roots and they have NULL order. Arel.sql("SUM(#{node_score}) IS NULL DESC, SUM(#{node_score})") end
roots_and_descendants_preordered()
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# File lib/closure_tree/numeric_deterministic_ordering.rb, line 72 def roots_and_descendants_preordered if _ct.dont_order_roots raise ClosureTree::RootOrderingDisabledError.new("Root ordering is disabled on this model") end join_sql = <<-SQL.squish JOIN #{_ct.quoted_hierarchy_table_name} anc_hier ON anc_hier.descendant_id = #{_ct.quoted_table_name}.#{_ct.quoted_id_column_name} JOIN #{_ct.quoted_table_name} anc ON anc.#{_ct.quoted_id_column_name} = anc_hier.ancestor_id JOIN ( SELECT descendant_id, max(generations) AS max_depth FROM #{_ct.quoted_hierarchy_table_name} GROUP BY descendant_id ) #{ _ct.t_alias_keyword } depths ON depths.descendant_id = anc.#{_ct.quoted_id_column_name} SQL joins(join_sql) .group("#{_ct.quoted_table_name}.#{_ct.quoted_id_column_name}") .reorder(_ct_sum_order_by) end