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We can use the column_names array that Active Record supplies
and define a function for every column. This method will perform the same actions as the
method_missing we used before, but instead of being called implicitly (as method_missing
does), they will be called explicitly. This will remove any ambiguity and let us be sure our
methods refer to columns in the database.
However, we??™ll need to rearrange our conditions class a little, for example:
module RQuery
class Conditions
def initialize(active_record, &blk)
@active_record = active_record
@columns = []
define_column_methods
blk.call(self) unless blk.nil?
end
def define_column_methods
active_record = @active_record
(class << self; self; end).class_eval do
active_record.column_names.each do |column|
define_method(column) do
column = Column.new(column_name)
@columns << column
column
end
end
end
end
def method_missing(name, *args)
raise "The column #{name} was not found on #{@active_record.class.name}"
end
end
end
The define_column_methods method is where our new work is getting done.


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