Class: ActiveRecord::ConnectionAdapters::Column

Inherits:
Object
  • Object
show all
Defined in:
activerecord/lib/active_record/connection_adapters/abstract/schema_definitions.rb

Overview

An abstract definition of a column in a table.

Direct Known Subclasses

MysqlColumn, PostgreSQLColumn, SQLiteColumn

Defined Under Namespace

Modules: Format

Constant Summary

TRUE_VALUES =
[true, 1, '1', 't', 'T', 'true', 'TRUE'].to_set
FALSE_VALUES =
[false, 0, '0', 'f', 'F', 'false', 'FALSE'].to_set

Instance Attribute Summary (collapse)

Class Method Summary (collapse)

Instance Method Summary (collapse)

Constructor Details

- (Column) initialize(name, default, sql_type = nil, null = true)

Instantiates a new column in the table.

name is the column's name, such as supplier_id in supplier_id int(11). default is the type-casted default value, such as new in sales_stage varchar(20) default 'new'. sql_type is used to extract the column's length, if necessary. For example 60 in company_name varchar(60). It will be mapped to one of the standard Rails SQL types in the type attribute. null determines if this column allows NULL values.



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# File 'activerecord/lib/active_record/connection_adapters/abstract/schema_definitions.rb', line 30

def initialize(name, default, sql_type = nil, null = true)
  @name, @sql_type, @null = name, sql_type, null
  @limit, @precision, @scale = extract_limit(sql_type), extract_precision(sql_type), extract_scale(sql_type)
  @type = simplified_type(sql_type)
  @default = extract_default(default)

  @primary = nil
end

Instance Attribute Details

- (Object) default (readonly)

Returns the value of attribute default



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# File 'activerecord/lib/active_record/connection_adapters/abstract/schema_definitions.rb', line 19

def default
  @default
end

- (Object) limit (readonly)

Returns the value of attribute limit



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# File 'activerecord/lib/active_record/connection_adapters/abstract/schema_definitions.rb', line 19

def limit
  @limit
end

- (Object) name (readonly)

Returns the value of attribute name



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# File 'activerecord/lib/active_record/connection_adapters/abstract/schema_definitions.rb', line 19

def name
  @name
end

- (Object) null (readonly)

Returns the value of attribute null



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# File 'activerecord/lib/active_record/connection_adapters/abstract/schema_definitions.rb', line 19

def null
  @null
end

- (Object) precision (readonly)

Returns the value of attribute precision



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# File 'activerecord/lib/active_record/connection_adapters/abstract/schema_definitions.rb', line 19

def precision
  @precision
end

- (Object) primary

Returns the value of attribute primary



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# File 'activerecord/lib/active_record/connection_adapters/abstract/schema_definitions.rb', line 20

def primary
  @primary
end

- (Object) scale (readonly)

Returns the value of attribute scale



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# File 'activerecord/lib/active_record/connection_adapters/abstract/schema_definitions.rb', line 19

def scale
  @scale
end

- (Object) sql_type (readonly)

Returns the value of attribute sql_type



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# File 'activerecord/lib/active_record/connection_adapters/abstract/schema_definitions.rb', line 19

def sql_type
  @sql_type
end

- (Object) type (readonly)

Returns the value of attribute type



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# File 'activerecord/lib/active_record/connection_adapters/abstract/schema_definitions.rb', line 19

def type
  @type
end

Class Method Details

+ (Object) binary_to_string(value)

Used to convert from BLOBs to Strings



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# File 'activerecord/lib/active_record/connection_adapters/abstract/schema_definitions.rb', line 124

def binary_to_string(value)
  value
end

+ (Object) string_to_binary(value)

Used to convert from Strings to BLOBs



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# File 'activerecord/lib/active_record/connection_adapters/abstract/schema_definitions.rb', line 119

def string_to_binary(value)
  value
end

+ (Object) string_to_date(string)



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# File 'activerecord/lib/active_record/connection_adapters/abstract/schema_definitions.rb', line 128

def string_to_date(string)
  return string unless string.is_a?(String)
  return nil if string.empty?

  fast_string_to_date(string) || fallback_string_to_date(string)
end

+ (Object) string_to_dummy_time(string)



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# File 'activerecord/lib/active_record/connection_adapters/abstract/schema_definitions.rb', line 142

def string_to_dummy_time(string)
  return string unless string.is_a?(String)
  return nil if string.empty?

  string_to_time "2000-01-01 #{string}"
end

+ (Object) string_to_time(string)



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# File 'activerecord/lib/active_record/connection_adapters/abstract/schema_definitions.rb', line 135

def string_to_time(string)
  return string unless string.is_a?(String)
  return nil if string.empty?

  fast_string_to_time(string) || fallback_string_to_time(string)
end

+ (Object) value_to_boolean(value)

convert something to a boolean



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# File 'activerecord/lib/active_record/connection_adapters/abstract/schema_definitions.rb', line 150

def value_to_boolean(value)
  if value.is_a?(String) && value.blank?
    nil
  else
    TRUE_VALUES.include?(value)
  end
end

+ (Object) value_to_decimal(value)

convert something to a BigDecimal



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# File 'activerecord/lib/active_record/connection_adapters/abstract/schema_definitions.rb', line 159

def value_to_decimal(value)
  # Using .class is faster than .is_a? and
  # subclasses of BigDecimal will be handled
  # in the else clause
  if value.class == BigDecimal
    value
  elsif value.respond_to?(:to_d)
    value.to_d
  else
    value.to_s.to_d
  end
end

Instance Method Details

- (Object) extract_default(default)



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# File 'activerecord/lib/active_record/connection_adapters/abstract/schema_definitions.rb', line 113

def extract_default(default)
  type_cast(default)
end

- (Boolean) has_default?



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# File 'activerecord/lib/active_record/connection_adapters/abstract/schema_definitions.rb', line 49

def has_default?
  !default.nil?
end

- (Object) human_name

Returns the human name of the column name.

Examples
Column.new('sales_stage', ...).human_name # => 'Sales stage'


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# File 'activerecord/lib/active_record/connection_adapters/abstract/schema_definitions.rb', line 109

def human_name
  Base.human_attribute_name(@name)
end

- (Object) klass

Returns the Ruby class that corresponds to the abstract data type.



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# File 'activerecord/lib/active_record/connection_adapters/abstract/schema_definitions.rb', line 54

def klass
  case type
    when :integer       then Fixnum
    when :float         then Float
    when :decimal       then BigDecimal
    when :datetime      then Time
    when :date          then Date
    when :timestamp     then Time
    when :time          then Time
    when :text, :string then String
    when :binary        then String
    when :boolean       then Object
  end
end

- (Boolean) number?

Returns true if the column is either of type integer, float or decimal.



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# File 'activerecord/lib/active_record/connection_adapters/abstract/schema_definitions.rb', line 45

def number?
  type == :integer || type == :float || type == :decimal
end

- (Boolean) text?

Returns true if the column is either of type string or text.



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# File 'activerecord/lib/active_record/connection_adapters/abstract/schema_definitions.rb', line 40

def text?
  type == :string || type == :text
end

- (Object) type_cast(value)

Casts value (which is a String) to an appropriate instance.



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# File 'activerecord/lib/active_record/connection_adapters/abstract/schema_definitions.rb', line 70

def type_cast(value)
  return nil if value.nil?
  case type
    when :string    then value
    when :text      then value
    when :integer   then value.to_i rescue value ? 1 : 0
    when :float     then value.to_f
    when :decimal   then self.class.value_to_decimal(value)
    when :datetime  then self.class.string_to_time(value)
    when :timestamp then self.class.string_to_time(value)
    when :time      then self.class.string_to_dummy_time(value)
    when :date      then self.class.string_to_date(value)
    when :binary    then self.class.binary_to_string(value)
    when :boolean   then self.class.value_to_boolean(value)
    else value
  end
end

- (Object) type_cast_code(var_name)



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# File 'activerecord/lib/active_record/connection_adapters/abstract/schema_definitions.rb', line 88

def type_cast_code(var_name)
  case type
    when :string    then nil
    when :text      then nil
    when :integer   then "(#{var_name}.to_i rescue #{var_name} ? 1 : 0)"
    when :float     then "#{var_name}.to_f"
    when :decimal   then "#{self.class.name}.value_to_decimal(#{var_name})"
    when :datetime  then "#{self.class.name}.string_to_time(#{var_name})"
    when :timestamp then "#{self.class.name}.string_to_time(#{var_name})"
    when :time      then "#{self.class.name}.string_to_dummy_time(#{var_name})"
    when :date      then "#{self.class.name}.string_to_date(#{var_name})"
    when :binary    then "#{self.class.name}.binary_to_string(#{var_name})"
    when :boolean   then "#{self.class.name}.value_to_boolean(#{var_name})"
    else nil
  end
end