Class: ActiveWarehouse::Aggregate::NoAggregate

Inherits:
Aggregate
  • Object
show all
Defined in:
lib/active_warehouse/aggregate/no_aggregate.rb

Overview

An aggregate which goes directly to the fact and dimensions to answer questions

Instance Attribute Summary

Attributes inherited from Aggregate

#cube_class

Instance Method Summary collapse

Methods inherited from Aggregate

#initialize

Constructor Details

This class inherits a constructor from ActiveWarehouse::Aggregate::Aggregate

Instance Method Details

#populate ⇒ Object

Populate the aggregate (in this case it is a no-op implementation)



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# File 'lib/active_warehouse/aggregate/no_aggregate.rb', line 8

def populate
  # do nothing
end

#query(*args) ⇒ Object

Query the aggregate



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# File 'lib/active_warehouse/aggregate/no_aggregate.rb', line 18

def query(*args)
  options = parse_query_args(*args)
  
  column_dimension_name = options[:column_dimension_name]
  column_hierarchy_name = options[:column_hierarchy_name]
  row_dimension_name = options[:row_dimension_name]
  row_hierarchy_name = options[:row_hierarchy_name]
  conditions = options[:conditions]
  cstage = options[:cstage] || 0
  rstage = options[:rstage] || 0
  filters = options[:filters] || {}
  
  fact_class = cube_class.fact_class
  column_dimension = fact_class.dimension_class(column_dimension_name)
  column_hierarchy = column_dimension.hierarchy(column_hierarchy_name)
  row_dimension = fact_class.dimension_class(row_dimension_name)
  row_hierarchy = row_dimension.hierarchy(row_hierarchy_name)
  
  used_dimensions = Set.new
  used_dimensions.merge([column_dimension_name, row_dimension_name])
  row_dim_reflection = fact_class.dimension_relationships[row_dimension_name].dependent_dimension_reflections
  used_dimensions.merge(row_dim_reflection.collect{|d| d.name})
  col_dim_reflection = fact_class.dimension_relationships[column_dimension_name].dependent_dimension_reflections
  used_dimensions.merge(col_dim_reflection.collect{|d| d.name})
  filters.each do |k,v|
    used_dimensions << k.split('.')[0]
  end
  if conditions
    cube_class.dimensions.each do |dimension|
      if conditions =~ /#{dimension}\./i
        used_dimensions << dimension
      end
    end
  end
  
  # This method assumes at most one dimension is hierarchical dimension
  # in the query params. TODO: need to handle when both row and column
  # are hierarchical dimensions.
  hierarchical_dimension = nil
  hierarchical_dimension_name = nil
  hierarchical_stage = nil
  
  if !column_dimension.hierarchical_dimension?
    current_column_name = column_hierarchy[cstage]
  else
    hierarchical_dimension = column_dimension
    hierarchical_dimension_name = column_dimension_name
    hierarchical_stage = cstage
    current_column_name = column_hierarchy[0]
  end
  
  if !row_dimension.hierarchical_dimension?
    current_row_name = row_hierarchy[rstage]
  else
    hierarchical_dimension = row_dimension
    hierarchical_dimension_name = row_dimension_name
    hierarchical_stage = rstage
    current_row_name = row_hierarchy[0]
  end

  fact_columns = cube_class.aggregate_fields.collect { |c| 
    agg_sql = ''
    quoted_label = cube_class.connection.quote_column_name(c.label)
    if hierarchical_dimension and !c.levels_from_parent.empty?
      bridge = hierarchical_dimension.bridge_class
      bridge_table_name = bridge.table_name
      levels_from_parent = bridge.levels_from_parent
      get_all = false
      c.levels_from_parent.each do |level|
        case level
        when :all
          agg_sql += "  #{c.strategy_name}(#{c.from_table_name}.#{c.name}) AS #{quoted_label})"
          get_all = true
        when :self
          agg_sql += " #{c.strategy_name}(CASE " if agg_sql.length == 0
          agg_sql += " WHEN #{bridge_table_name}.#{levels_from_parent} = 0 THEN #{c.from_table_name}.#{c.name} \n"
        when Integer  
          agg_sql += " #{c.strategy_name}(CASE " if agg_sql.length == 0              
          agg_sql += " WHEN #{bridge_table_name}.#{levels_from_parent} = #{level} then #{c.from_table_name}.#{c.name} \n"
        else
          raise ArgumentError, "Each element to :levels_from_parent option must be :all, :self, or Integer"
        end
      end
      agg_sql += " ELSE 0 END) AS #{quoted_label}" unless get_all
    else
      agg_sql = "  #{c.strategy_name}(#{c.from_table_name}.#{c.name}) AS #{quoted_label}" 
    end
    agg_sql
  }.join(",\n")

  sql = ''
  sql += "SELECT\n"
  sql += "  #{column_dimension_name}.#{current_column_name},\n"
  sql += "  #{row_dimension_name}.#{current_row_name},\n"
  sql += fact_columns
  sql += "\nFROM\n"

  sql += "  #{fact_class.table_name}"
  cube_class.dimensions_hierarchies.each do |dimension_name, hierarchy_names|
    next if !used_dimensions.include?(dimension_name)
    dimension = fact_class.dimension_class(dimension_name)
    if !dimension.hierarchical_dimension?
      sql += "\nJOIN #{dimension.table_name} as #{dimension_name}"
      sql += "\n  ON #{fact_class.table_name}.#{fact_class.foreign_key_for(dimension_name)} = "
      sql += "#{dimension_name}.#{dimension.primary_key}"
    else
      dimension_bridge = dimension.bridge_class
      sql += "\nJOIN #{dimension_bridge.table_name}"
      sql += "\n  ON #{fact_class.table_name}.#{fact_class.foreign_key_for(dimension_name)} = "
      sql += "#{dimension_bridge.table_name}.#{dimension.parent_foreign_key}"
      if dimension.slowly_changing_dimension?
        sql += " and (#{dimension_bridge.table_name}.#{dimension_bridge.effective_date} <= "
        sql += "#{fact_class.slowly_changes_over_name(dimension_name)}."
        sql += "#{fact_class.slowly_changes_over_class(dimension_name).sql_date_stamp} "
        sql += "and #{dimension_bridge.table_name}.#{dimension_bridge.expiration_date} >= "
        sql += "#{fact_class.slowly_changes_over_name(dimension_name)}."
        sql += "#{fact_class.slowly_changes_over_class(dimension_name).sql_date_stamp}) "
      end
      sql += "\nJOIN #{dimension.table_name} as #{dimension_name}"
      sql += "\n  ON #{dimension_bridge.table_name}.#{dimension.child_foreign_key} = "
      sql += "#{dimension_name}.#{dimension.primary_key}"
    end
  end

  # build the where clause
  # first add conditions
  where_clause = Array(conditions)
  
  # apply filters
  filters.each do |key, value|
    dimension_name, column = key.split('.')
    where_clause << "#{dimension_name}.#{column} = #{cube_class.connection.quote(value)}"
  end
  sql += %Q(\nWHERE\n  #{where_clause.join(" AND\n  ")} ) if where_clause.length > 0

  # for hierarchical dimension we need to add where clause in for drill downs
  if !hierarchical_dimension.nil?
    if where_clause.length == 0
      sql += "\n WHERE "
    else 
      sql += " \n AND "
    end
    sql += "\n #{hierarchical_dimension_name}.#{hierarchical_dimension.primary_key} IN ( "
    sql += "\n SELECT #{hierarchical_dimension.parent_foreign_key} FROM #{hierarchical_dimension.bridge_class.table_name} "
    if hierarchical_stage == 0   
      sql += "\n WHERE #{hierarchical_dimension.bridge_class.top_flag} = #{connection.send(:quote, hierarchical_dimension.bridge_class.top_flag_value)})"
    else
      sql += "\n WHERE #{hierarchical_dimension.child_foreign_key} = #{hierarchical_stage} AND #{hierarchical_dimension.levels_from_parent} = 1)"
    end
  end
  
  sql += "\nGROUP BY\n"
  sql += "  #{column_dimension_name}.#{current_column_name},\n"
  sql += "  #{row_dimension_name}.#{current_row_name}"
  
  if options[:order]
    order_by = options[:order]
    order_by = [order_by] if order_by.is_a?(String)
    order_by.collect!{ |v| cube_class.connection.quote_column_name(order_by) }
    sql += %Q(\nORDER BY\n  #{order_by.join(",\n")})
  end
  
  result = ActiveWarehouse::CubeQueryResult.new(
    cube_class.aggregate_fields
  )
  
  cube_class.connection.select_all(sql).each do |row|
    result.add_data(row.delete(current_row_name.to_s),
                    row.delete(current_column_name.to_s),
                    row) # the rest of the members of row are the fact columns
  end
  
  result
end