Class: ActiveWarehouse::Aggregate::RolapAggregate

Inherits:
Aggregate
  • Object
show all
Includes:
RolapCommon
Defined in:
lib/active_warehouse/aggregate/rolap_aggregate.rb

Overview

Basic implementation of a ROLAP engine that stores all possible combinations of fact and dimensional values for a specific cube.

Instance Attribute Summary

Attributes inherited from Aggregate

#cube_class

Instance Method Summary collapse

Methods included from RolapCommon

#aggregate_fields, #aggregated_fact_column_sql, #dimensions_to_columns, #flat_table_name, #rollup_table_name, #tables_and_joins

Methods inherited from Aggregate

#initialize

Constructor Details

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

Instance Method Details

#populate(options = {}) ⇒ Object

Build and populate the data store



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# File 'lib/active_warehouse/aggregate/rolap_aggregate.rb', line 11

def populate(options={})
  populate_rollup_cube
end

#query(*args) ⇒ Object

Query the aggregate, returning a QueryResult object



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# File 'lib/active_warehouse/aggregate/rolap_aggregate.rb', line 16

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]
  rstage = options[:rstage]
  filters = options[:filters]
  
  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)
  current_column_name = column_hierarchy[cstage]
  current_row_name = row_hierarchy[rstage]
  full_column_name = "#{column_dimension_name}_#{current_column_name}"
  full_row_name = "#{row_dimension_name}_#{current_row_name}"

  # build the SQL query
  sql = ''
  sql += 'SELECT '
  sql += "#{full_column_name} AS #{current_column_name},"
  sql += "#{full_row_name} AS #{current_row_name},"
  sql += aggregate_fields.collect{|c| "#{c.label_for_table} as '#{c.label}'"}.join(",")
  sql += " FROM #{rollup_table_name} "

  # build the where clause
  where_clause = []
  0.upto(column_hierarchy.length - 1) do |stage|
    column_name = column_hierarchy[stage]
    name = "#{column_dimension_name}_#{column_name}"
    filter_value = filters.delete(column_name)
    if filter_value
      where_clause << "#{name} = '#{filter_value}'" # TODO: protect from
                                                    # SQL injection
    else
      where_clause << "#{name} is null" if stage > cstage
    end
  end
  0.upto(row_hierarchy.length - 1) do |stage|
    row_name = row_hierarchy[stage]
    name = "#{row_dimension_name}_#{row_name}"
    filter_value = filters.delete(row_name)
    if filter_value
      where_clause << "#{name} = '#{filter_value}'" # TODO: protect from
                                                    # SQL injection
    else
      where_clause << "#{name} is null" if stage > rstage
    end
  end
  where_clause << "#{full_column_name} is not null"
  where_clause << "#{full_row_name} is not null"
  filters.each do |key, value|
    dimension_name, column = key.split('.')
    where_clause << "#{dimension_name}_#{column} = '#{value}'" # TODO: protect from SQL injection
  end
  sql += %Q( WHERE #{where_clause.join(" AND ")} ) if where_clause.length > 0
  
   if conditions
      sql += "\n WHERE\n" unless sql =~ /WHERE/i
      sql += conditions
    end
  
  # execute the query and return the results as a CubeQueryResult object
  result = ActiveWarehouse::CubeQueryResult.new(
    aggregate_fields
  )
  rows = connection.select_all(sql)
#        fact_column_names = fact_class.aggregate_fields.collect{|f| f.to_s}
  rows.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