Class: Chicago::Schema::CalculatedColumn Abstract

Inherits:
QueryColumn show all
Defined in:
lib/chicago/schema/query_column.rb

Overview

This class is abstract.

Direct Known Subclasses

AggregateColumn, CountColumn

Class Method Summary collapse

Instance Method Summary collapse

Methods inherited from QueryColumn

column, #method_missing, #qualified_label

Constructor Details

#initialize(column, operation) ⇒ CalculatedColumn

Returns a new instance of CalculatedColumn.



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# File 'lib/chicago/schema/query_column.rb', line 139

def initialize(column, operation)
  super column
  @operation = operation
  @defined_operation = operation
  normalize_operation
end

Dynamic Method Handling

This class handles dynamic methods through the method_missing method in the class Chicago::Schema::QueryColumn

Class Method Details

.make(operation, column) ⇒ Object 



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# File 'lib/chicago/schema/query_column.rb', line 131

def self.make(operation, column)
  if operation == :count
    CountColumn.new(column)
  else
    AggregateColumn.new(column, operation)
  end
end

Instance Method Details

#column_alias ⇒ Object 



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# File 'lib/chicago/schema/query_column.rb', line 146

def column_alias
  "#{@column.column_alias}.count".to_sym
end

#filter_dataset(ds, filter) ⇒ Object 



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# File 'lib/chicago/schema/query_column.rb', line 154

def filter_dataset(ds, filter)
  ds.having(filter)
end

#group_name ⇒ Object 



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# File 'lib/chicago/schema/query_column.rb', line 150

def group_name
  nil
end