1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
|
require 'set'
module Arel
class TypecastError < StandardError ; end
class Attribute
attr_reader :relation, :name, :alias, :ancestor
def initialize(relation, name, options = {})
@relation = relation # this is actually a table (I think)
@name = name
@alias = options[:alias]
@ancestor = options[:ancestor]
end
def engine
@relation.engine
end
def christener
@relation.christener
end
def == other
super ||
Attribute === other &&
@relation == other.relation &&
@name == other.name &&
@alias == other.alias &&
@ancestor == other.ancestor
end
def named?(hypothetical_name)
(@alias || name).to_s == hypothetical_name.to_s
end
def aggregation?
false
end
def eval(row)
row[self]
end
module Transformations
def self.included(klass)
klass.send :alias_method, :eql?, :==
end
def hash
@hash ||= name.hash + root.relation.hash
end
def as(aliaz = nil)
Attribute.new(relation, name, :alias => aliaz, :ancestor => self)
end
def bind(new_relation)
relation == new_relation ? self : Attribute.new(new_relation, name, :alias => @alias, :ancestor => self)
end
def to_attribute(relation)
bind(relation)
end
end
include Transformations
module Congruence
def history
@history ||= [self] + (ancestor ? ancestor.history : [])
end
def join?
relation.join?
end
def root
history.last
end
def original_relation
@original_relation ||= original_attribute.relation
end
def original_attribute
@original_attribute ||= history.detect { |a| !a.join? }
end
def find_correlate_in(relation)
relation[self] || self
end
def descends_from?(other)
history.include?(other)
end
def /(other)
other ? (history & other.history).size : 0
end
end
include Congruence
def eq(other)
Predicates::Equality.new(self, other)
end
def eq_any(*others)
Predicates::Any.build(Predicates::Equality, self, *others)
end
def eq_all(*others)
Predicates::All.build(Predicates::Equality, self, *others)
end
def not_eq(other)
Predicates::Inequality.new(self, other)
end
def not_eq_any(*others)
Predicates::Any.build(Predicates::Inequality, self, *others)
end
def not_eq_all(*others)
Predicates::All.build(Predicates::Inequality, self, *others)
end
def lt(other)
Predicates::LessThan.new(self, other)
end
def lt_any(*others)
Predicates::Any.build(Predicates::LessThan, self, *others)
end
def lt_all(*others)
Predicates::All.build(Predicates::LessThan, self, *others)
end
def lteq(other)
Predicates::LessThanOrEqualTo.new(self, other)
end
def lteq_any(*others)
Predicates::Any.build(Predicates::LessThanOrEqualTo, self, *others)
end
def lteq_all(*others)
Predicates::All.build(Predicates::LessThanOrEqualTo, self, *others)
end
def gt(other)
Predicates::GreaterThan.new(self, other)
end
def gt_any(*others)
Predicates::Any.build(Predicates::GreaterThan, self, *others)
end
def gt_all(*others)
Predicates::All.build(Predicates::GreaterThan, self, *others)
end
def gteq(other)
Predicates::GreaterThanOrEqualTo.new(self, other)
end
def gteq_any(*others)
Predicates::Any.build(Predicates::GreaterThanOrEqualTo, self, *others)
end
def gteq_all(*others)
Predicates::All.build(Predicates::GreaterThanOrEqualTo, self, *others)
end
def matches(other)
Predicates::Match.new(self, other)
end
def matches_any(*others)
Predicates::Any.build(Predicates::Match, self, *others)
end
def matches_all(*others)
Predicates::All.build(Predicates::Match, self, *others)
end
def not_matches(other)
Predicates::NotMatch.new(self, other)
end
def not_matches_any(*others)
Predicates::Any.build(Predicates::NotMatch, self, *others)
end
def not_matches_all(*others)
Predicates::All.build(Predicates::NotMatch, self, *others)
end
def in(other)
Predicates::In.new(self, other)
end
def in_any(*others)
Predicates::Any.build(Predicates::In, self, *others)
end
def in_all(*others)
Predicates::All.build(Predicates::In, self, *others)
end
def not_in(other)
Predicates::NotIn.new(self, other)
end
def not_in_any(*others)
Predicates::Any.build(Predicates::NotIn, self, *others)
end
def not_in_all(*others)
Predicates::All.build(Predicates::NotIn, self, *others)
end
module Expressions
def count(distinct = false)
distinct ? Distinct.new(self).count : Count.new(self)
end
def sum
Sum.new(self)
end
def maximum
Maximum.new(self)
end
def minimum
Minimum.new(self)
end
def average
Average.new(self)
end
end
include Expressions
module Orderings
def asc
Ascending.new(self)
end
def desc
Descending.new(self)
end
alias_method :to_ordering, :asc
end
include Orderings
module Types
def type_cast(value)
if root == self
raise NotImplementedError, "#type_cast should be implemented in a subclass."
else
root.type_cast(value)
end
end
def type_cast_to_numeric(value, method)
return unless value
if value.respond_to?(:to_str)
str = value.to_str.strip
return if str.empty?
return $1.send(method) if str =~ /\A(-?(?:0|[1-9]\d*)(?:\.\d+)?|(?:\.\d+))\z/
elsif value.respond_to?(method)
return value.send(method)
end
raise typecast_error(value)
end
def typecast_error(value)
raise TypecastError, "could not typecast #{value.inspect} to #{self.class.name.split('::').last}"
end
end
include Types
def column
original_relation.column_for(self)
end
def format(object)
object.to_sql(Sql::Attribute.new(self))
end
def to_sql(formatter = Sql::WhereCondition.new(relation))
formatter.attribute self
end
end
end
|