Class: Devlin::Query

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

Instance Attribute Summary collapse

Instance Method Summary collapse

Constructor Details

#initialize(parent, q) ⇒ Query

Returns a new instance of Query.



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

def initialize(parent, q)
  @parent = parent
  @query = YAML.load(q)
  @scope = parent.scope(query['scope'])
  @select = query['select']
  @conditions = query['conditions']
  @group = query['group']
end

Instance Attribute Details

#conditionsObject (readonly)

Returns the value of attribute conditions.



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# File 'lib/devlin/query.rb', line 3

def conditions
  @conditions
end

#groupObject (readonly)

Returns the value of attribute group.



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# File 'lib/devlin/query.rb', line 3

def group
  @group
end

#queryObject (readonly)

Returns the value of attribute query.



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# File 'lib/devlin/query.rb', line 3

def query
  @query
end

#scopeObject (readonly)

Returns the value of attribute scope.



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# File 'lib/devlin/query.rb', line 3

def scope
  @scope
end

#selectObject (readonly)

Returns the value of attribute select.



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# File 'lib/devlin/query.rb', line 3

def select
  @select
end

Instance Method Details

#resultObject

This method returns the resulting relation to calculate the given query



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

def result
  res = @scope.relation
  res = res.select(self.select.map { |c| @scope.column(c).select_definition })
  @conditions.each do |col, val|
    col, op = col.split('.')
    res = case op
    when 'g'
      res.where(["#{@scope.column(col).definition}>?", val])
    when 'geq'
      res.where(["#{@scope.column(col).definition}>=?", val])
    when 'l'
      res.where(["#{@scope.column(col).definition}<?", val])
    when 'leq'
      res.where(["#{@scope.column(col).definition}<=?", val])
    when 'in'
      res.where(["#{@scope.column(col).definition} IN (?)", val])
    else
      res.where(["#{@scope.column(col).definition}=?", val])
    end
  end
  res = res.group(self.group.map { |c| @scope.column(c).definition })
  res
end