# Source code for the PostgreSQLAdapter extensions.
module ActiveRecord #:nodoc:
  module ConnectionAdapters #:nodoc:
    # Adds new functionality to ActiveRecord PostgreSQLAdapter.
    class PostgreSQLAdapter < AbstractAdapter
    
      protected
      # Call +bulk_load+, as that method wraps this method.
      # 
      # Bulk load the data in the specified file.
      #
      # Options:
      # * <tt>:ignore</tt> -- Ignore the specified number of lines from the source file. In the case of PostgreSQL
      #   only the first line will be ignored from the source file regardless of the number of lines specified.
      # * <tt>:columns</tt> -- Array of column names defining the source file column order
      # * <tt>:fields</tt> -- Hash of options for fields:
      # * <tt>:delimited_by</tt> -- The field delimiter
      # * <tt>:enclosed_by</tt> -- The field enclosure
      def do_bulk_load(file, table_name, options={})
        q = "COPY #{table_name} "
        q << "(#{options[:columns].join(',')}) " if options[:columns]
        q << "FROM '#{File.expand_path(file)}' "
        if options[:fields]
          q << "WITH "
          q << "DELIMITER '#{options[:fields][:delimited_by]}' " if options[:fields][:delimited_by]
          if options[:fields][:enclosed_by]
            q << "CSV "
            q << "HEADER " if options[:ignore] > 0
            q << "QUOTE '#{options[:fields][:enclosed_by]}' " if options[:fields][:enclosed_by]
          end
        end
        
        execute(q)
      end
    end
  end
end