Class: ASeriesOfTubes::TubeRecord::SQLObject

Inherits:
Object
  • Object
show all
Defined in:
lib/a_series_of_tubes/tube_record/sql_object.rb

Class Method Summary collapse

Instance Method Summary collapse

Constructor Details

#initialize(params = {}) ⇒ SQLObject

Returns a new instance of SQLObject.



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# File 'lib/a_series_of_tubes/tube_record/sql_object.rb', line 56

def initialize(params = {})
  params.each do |attr_name, value|
    if self.class.columns.include?(attr_name.to_sym)
      self.send("#{attr_name}=", value)
    else
      raise "unknown attribute '#{attr_name}'"
    end
  end
end

Class Method Details

.all ⇒ Object 



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# File 'lib/a_series_of_tubes/tube_record/sql_object.rb', line 13

def self.all
  self.parse_all(DBConnection.execute(<<-SQL))
    SELECT
      *
    FROM
      #{self.table_name}
  SQL
end

.columns ⇒ Object 



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# File 'lib/a_series_of_tubes/tube_record/sql_object.rb', line 4

def self.columns
  @columns ||= DBConnection.execute2(<<-SQL).first.map(&:to_sym)
    SELECT
      *
    FROM
      #{self.table_name}
  SQL
end

.finalize! ⇒ Object 



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# File 'lib/a_series_of_tubes/tube_record/sql_object.rb', line 41

def self.finalize!
  self.columns.each do |column|
    define_method(column) { self.attributes[column] }
    define_method("#{column}=") { |value| self.attributes[column] = value }
  end
end

.find(id) ⇒ Object 



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# File 'lib/a_series_of_tubes/tube_record/sql_object.rb', line 26

def self.find(id)
  result = DBConnection.execute(<<-SQL, id: id).first
    SELECT
      *
    FROM
      #{self.table_name}
    WHERE
      #{self.table_name}.id = :id
    LIMIT
      1
  SQL

  self.new(result) if result
end

.parse_all(results) ⇒ Object 



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# File 'lib/a_series_of_tubes/tube_record/sql_object.rb', line 22

def self.parse_all(results)
  results.map { |params| self.new(params) }
end

.table_name ⇒ Object 



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# File 'lib/a_series_of_tubes/tube_record/sql_object.rb', line 48

def self.table_name
  @table_name ||= self.to_s.tableize
end

.table_name=(table_name) ⇒ Object 



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# File 'lib/a_series_of_tubes/tube_record/sql_object.rb', line 52

def self.table_name=(table_name)
  @table_name = table_name
end

Instance Method Details

#attribute_values ⇒ Object 



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# File 'lib/a_series_of_tubes/tube_record/sql_object.rb', line 70

def attribute_values
  @attributes.keys.map { |k| @attributes[k] }
end

#attributes ⇒ Object 



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# File 'lib/a_series_of_tubes/tube_record/sql_object.rb', line 66

def attributes
  @attributes ||= {}
end

#destroy ⇒ Object 



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# File 'lib/a_series_of_tubes/tube_record/sql_object.rb', line 106

def destroy
  return unless self.id

  ASeriesOfTubes::TubeRecord::DBConnection.execute(<<-SQL)
    DELETE FROM
      #{self.class.table_name}
    WHERE
      id = #{self.id}
  SQL
end

#insert ⇒ Object 



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# File 'lib/a_series_of_tubes/tube_record/sql_object.rb', line 74

def insert
  columns = self.class.columns.drop(1)
  question_marks = (['?'] * columns.length)

  ASeriesOfTubes::TubeRecord::DBConnection.execute(<<-SQL, *attribute_values)
    INSERT INTO
      #{self.class.table_name} (#{columns.join(',')})
    VALUES
      (#{question_marks.join(',')})
  SQL

  self.id = ASeriesOfTubes::TubeRecord::DBConnection.last_insert_row_id
end

#save ⇒ Object 



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# File 'lib/a_series_of_tubes/tube_record/sql_object.rb', line 102

def save
  self.id ? self.update : self.insert
end

#update ⇒ Object 



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# File 'lib/a_series_of_tubes/tube_record/sql_object.rb', line 88

def update
  columns = self.class.columns
  set_values = columns.map { |attr_name| "#{attr_name} = ?" }

  ASeriesOfTubes::TubeRecord::DBConnection.execute(<<-SQL, *attribute_values)
    UPDATE
      #{self.class.table_name}
    SET
      #{set_values.join(',')}
    WHERE
      id = #{self.id}
  SQL
end