Class: DataObjects::Reader

Inherits:
Object
  • Object
show all
Includes:
Enumerable
Defined in:
lib/data_objects/reader.rb

Overview

Abstract class to read rows from a query result

Instance Method Summary collapse

Instance Method Details

#close ⇒ Object

Close the reader discarding any unread results.

Raises:



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# File 'lib/data_objects/reader.rb', line 17

def close
  raise NotImplementedError
end

#each ⇒ Object

Yield each row to the given block as a Hash



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# File 'lib/data_objects/reader.rb', line 32

def each
  begin
    while next!
      row = {}
      fields.each_with_index { |field, index| row[field] = values[index] }
      yield row
    end
  ensure
    close
  end
  self
end

#field_count ⇒ Object

Return the number of fields in the result set.

Raises:



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# File 'lib/data_objects/reader.rb', line 27

def field_count
  raise NotImplementedError
end

#fields ⇒ Object

Return the array of field names

Raises:



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# File 'lib/data_objects/reader.rb', line 7

def fields
  raise NotImplementedError
end

#next! ⇒ Object

Discard the current row (if any) and read the next one (returning true), or return nil if there is no further row.

Raises:



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# File 'lib/data_objects/reader.rb', line 22

def next!
  raise NotImplementedError
end

#values ⇒ Object

Return the array of field values for the current row. Not legal after next! has returned false or before it’s been called

Raises:



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# File 'lib/data_objects/reader.rb', line 12

def values
  raise NotImplementedError
end