Class: ActiveRecord::ConnectionAdapters::Column

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

Overview

An abstract definition of a column in a table.

Defined Under Namespace

Modules: Format

Constant Summary collapse

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

Instance Attribute Summary collapse

Class Method Summary collapse

Instance Method Summary collapse

Constructor Details

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

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.


29
30
31
32
33
34
35
36
37
38
39
40
# File 'activerecord/lib/active_record/connection_adapters/column.rb', line 29

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

Instance Attribute Details

#coderObject Also known as: encoded?

Returns the value of attribute coder


17
18
19
# File 'activerecord/lib/active_record/connection_adapters/column.rb', line 17

def coder
  @coder
end

#defaultObject (readonly)

Returns the value of attribute default


16
17
18
# File 'activerecord/lib/active_record/connection_adapters/column.rb', line 16

def default
  @default
end

#limitObject (readonly)

Returns the value of attribute limit


16
17
18
# File 'activerecord/lib/active_record/connection_adapters/column.rb', line 16

def limit
  @limit
end

#nameObject (readonly)

Returns the value of attribute name


16
17
18
# File 'activerecord/lib/active_record/connection_adapters/column.rb', line 16

def name
  @name
end

#nullObject (readonly)

Returns the value of attribute null


16
17
18
# File 'activerecord/lib/active_record/connection_adapters/column.rb', line 16

def null
  @null
end

#precisionObject (readonly)

Returns the value of attribute precision


16
17
18
# File 'activerecord/lib/active_record/connection_adapters/column.rb', line 16

def precision
  @precision
end

#primaryObject

Returns the value of attribute primary


17
18
19
# File 'activerecord/lib/active_record/connection_adapters/column.rb', line 17

def primary
  @primary
end

#scaleObject (readonly)

Returns the value of attribute scale


16
17
18
# File 'activerecord/lib/active_record/connection_adapters/column.rb', line 16

def scale
  @scale
end

#sql_typeObject (readonly)

Returns the value of attribute sql_type


16
17
18
# File 'activerecord/lib/active_record/connection_adapters/column.rb', line 16

def sql_type
  @sql_type
end

#typeObject (readonly)

Returns the value of attribute type


16
17
18
# File 'activerecord/lib/active_record/connection_adapters/column.rb', line 16

def type
  @type
end

Class Method Details

.binary_to_string(value) ⇒ Object

Used to convert from BLOBs to Strings


134
135
136
# File 'activerecord/lib/active_record/connection_adapters/column.rb', line 134

def binary_to_string(value)
  value
end

.string_to_binary(value) ⇒ Object

Used to convert from Strings to BLOBs


129
130
131
# File 'activerecord/lib/active_record/connection_adapters/column.rb', line 129

def string_to_binary(value)
  value
end

.string_to_dummy_time(string) ⇒ Object


156
157
158
159
160
161
162
163
164
165
166
167
# File 'activerecord/lib/active_record/connection_adapters/column.rb', line 156

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

  dummy_time_string = "2000-01-01 #{string}"

  fast_string_to_time(dummy_time_string) || begin
    time_hash = Date._parse(dummy_time_string)
    return nil if time_hash[:hour].nil?
    new_time(*time_hash.values_at(:year, :mon, :mday, :hour, :min, :sec, :sec_fraction))
  end
end

.string_to_time(string) ⇒ Object


149
150
151
152
153
154
# File 'activerecord/lib/active_record/connection_adapters/column.rb', line 149

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

.value_to_boolean(value) ⇒ Object

convert something to a boolean


170
171
172
173
174
175
176
# File 'activerecord/lib/active_record/connection_adapters/column.rb', line 170

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

.value_to_date(value) ⇒ Object


138
139
140
141
142
143
144
145
146
147
# File 'activerecord/lib/active_record/connection_adapters/column.rb', line 138

def value_to_date(value)
  if value.is_a?(String)
    return nil if value.empty?
    fast_string_to_date(value) || fallback_string_to_date(value)
  elsif value.respond_to?(:to_date)
    value.to_date
  else
    value
  end
end

.value_to_decimal(value) ⇒ Object

convert something to a BigDecimal


190
191
192
193
194
195
196
197
198
199
200
201
# File 'activerecord/lib/active_record/connection_adapters/column.rb', line 190

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

.value_to_integer(value) ⇒ Object

Used to convert values to integer. handle the case when an integer column is used to store boolean values


180
181
182
183
184
185
186
187
# File 'activerecord/lib/active_record/connection_adapters/column.rb', line 180

def value_to_integer(value)
  case value
  when TrueClass, FalseClass
    value ? 1 : 0
  else
    value.to_i rescue nil
  end
end

Instance Method Details

#binary?Boolean

Returns:

  • (Boolean)

69
70
71
# File 'activerecord/lib/active_record/connection_adapters/column.rb', line 69

def binary?
  type == :binary
end

#extract_default(default) ⇒ Object


118
119
120
# File 'activerecord/lib/active_record/connection_adapters/column.rb', line 118

def extract_default(default)
  type_cast(default)
end

#has_default?Boolean

Returns:

  • (Boolean)

52
53
54
# File 'activerecord/lib/active_record/connection_adapters/column.rb', line 52

def has_default?
  !default.nil?
end

#human_nameObject

Returns the human name of the column name.

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

114
115
116
# File 'activerecord/lib/active_record/connection_adapters/column.rb', line 114

def human_name
  Base.human_attribute_name(@name)
end

#klassObject

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


57
58
59
60
61
62
63
64
65
66
67
# File 'activerecord/lib/active_record/connection_adapters/column.rb', line 57

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

#number?Boolean

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

Returns:

  • (Boolean)

48
49
50
# File 'activerecord/lib/active_record/connection_adapters/column.rb', line 48

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

#string_to_binary(value) ⇒ Object

Used to convert from Strings to BLOBs


123
124
125
# File 'activerecord/lib/active_record/connection_adapters/column.rb', line 123

def string_to_binary(value)
  self.class.string_to_binary(value)
end

#text?Boolean

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

Returns:

  • (Boolean)

43
44
45
# File 'activerecord/lib/active_record/connection_adapters/column.rb', line 43

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

#type_cast(value) ⇒ Object

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


90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
# File 'activerecord/lib/active_record/connection_adapters/column.rb', line 90

def type_cast(value)
  return nil if value.nil?
  return coder.load(value) if encoded?

  klass = self.class

  case type
  when :string, :text        then value
  when :integer              then klass.value_to_integer(value)
  when :float                then value.to_f
  when :decimal              then klass.value_to_decimal(value)
  when :datetime, :timestamp then klass.string_to_time(value)
  when :time                 then klass.string_to_dummy_time(value)
  when :date                 then klass.value_to_date(value)
  when :binary               then klass.binary_to_string(value)
  when :boolean              then klass.value_to_boolean(value)
  else value
  end
end

#type_cast_for_write(value) ⇒ Object

Casts a Ruby value to something appropriate for writing to the database.


74
75
76
77
78
79
80
81
82
83
84
85
86
87
# File 'activerecord/lib/active_record/connection_adapters/column.rb', line 74

def type_cast_for_write(value)
  return value unless number?

  case value
  when FalseClass
    0
  when TrueClass
    1
  when String
    value.presence
  else
    value
  end
end