Class: RecordCache::Query

Inherits:
Object
  • Object
show all
Defined in:
lib/record_cache/query.rb

Overview

Container for the Query parameters

Instance Attribute Summary collapse

Instance Method Summary collapse

Constructor Details

#initialize(equality = nil) ⇒ Query

Returns a new instance of Query.



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# File 'lib/record_cache/query.rb', line 7

def initialize(equality = nil)
  @wheres = equality || {}
  @sort_orders = []
  @limit = nil
  @where_ids = {}
end

Instance Attribute Details

#limit ⇒ Object

Returns the value of attribute limit.



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# File 'lib/record_cache/query.rb', line 5

def limit
  @limit
end

#sort_orders ⇒ Object (readonly)

Returns the value of attribute sort_orders.



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# File 'lib/record_cache/query.rb', line 5

def sort_orders
  @sort_orders
end

#wheres ⇒ Object (readonly)

Returns the value of attribute wheres.



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# File 'lib/record_cache/query.rb', line 5

def wheres
  @wheres
end

Instance Method Details

#cache_key ⇒ Object

retrieve a unique key for this Query (used in RequestCache)



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# File 'lib/record_cache/query.rb', line 49

def cache_key
  @cache_key ||= generate_key
end

#order_by(attribute, ascending = true) ⇒ Object

Add a sort order to the query



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# File 'lib/record_cache/query.rb', line 36

def order_by(attribute, ascending = true)
  @sort_orders << [attribute.to_s, ascending]
end

#sorted? ⇒ Boolean

Returns:

  • (Boolean) 


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# File 'lib/record_cache/query.rb', line 40

def sorted?
  @sort_orders.size > 0
end

#to_s ⇒ Object 



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# File 'lib/record_cache/query.rb', line 53

def to_s
  s = "SELECT "
  s << @wheres.map{|k,v| "#{k} = #{v.inspect}"}.join(" AND ")
  if @sort_orders.size > 0
    order_by = @sort_orders.map{|attr,asc| "#{attr} #{asc ? 'ASC' : 'DESC'}"}.join(', ')
    s << " ORDER_BY #{order_by}"
  end
  s << " LIMIT #{@limit}" if @limit
  s
end

#where(attribute, values) ⇒ Object

Set equality of an attribute (usually found in where clause) Returns false if another attribute values was already set (making this query uncachable)



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# File 'lib/record_cache/query.rb', line 16

def where(attribute, values)
  @wheres[attribute.to_sym] = values if attribute
end

#where_id(attribute) ⇒ Object

Retrieve the single id (positive integer) for the given attribute from the where statements Returns nil if no the attribute is not present, or if it contains an array



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# File 'lib/record_cache/query.rb', line 29

def where_id(attribute)
  ids = where_ids(attribute)
  return nil unless ids && ids.size == 1
  ids.first
end

#where_ids(attribute) ⇒ Object

Retrieve the ids (array of positive integers) for the given attribute from the where statements Returns nil if no the attribute is not present



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# File 'lib/record_cache/query.rb', line 22

def where_ids(attribute)
  return @where_ids[attribute] if @where_ids.key?(attribute)
  @where_ids[attribute] ||= array_of_positive_integers(@wheres[attribute])
end