module Sequel::DuplicateColumnsHandler

   # File lib/sequel/extensions/duplicate_columns_handler.rb
46 def on_duplicate_columns(handler = (raise Error, "Must provide either an argument or a block to on_duplicate_columns" unless defined?(yield); nil), &block)
47   raise Error, "Cannot provide both an argument and a block to on_duplicate_columns" if handler && block
48   clone(:on_duplicate_columns=>handler||block)
49 end

   # File lib/sequel/extensions/duplicate_columns_handler.rb
54 def columns=(cols)
55   if cols && cols.uniq.size != cols.size
56     handle_duplicate_columns(cols)
57   end
58   super
59 end

   # File lib/sequel/extensions/duplicate_columns_handler.rb
76 def duplicate_columns_handler_type(cols)
77   handler = opts.fetch(:on_duplicate_columns){db.opts.fetch(:on_duplicate_columns, :warn)}
78 
79   if handler.respond_to?(:call)
80     handler.call(cols)
81   else
82     handler
83   end
84 end

   # File lib/sequel/extensions/duplicate_columns_handler.rb
62 def handle_duplicate_columns(cols)
63   message = "#{caller(*CALLER_ARGS).first}: One or more duplicate columns present in #{cols.inspect}"
64 
65   case duplicate_columns_handler_type(cols)
66   when :raise, 'raise'
67     raise DuplicateColumnError, message
68   when :warn, 'warn'
69     warn message
70   end
71 end