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
298
299
300
301
302
303
304
305
306
|
module Arel
module Predicates
class Predicate
def or(other_predicate)
Or.new(self, other_predicate)
end
def and(other_predicate)
And.new(self, other_predicate)
end
def complement
Not.new(self)
end
def not
self.complement
end
end
class Polyadic < Predicate
attr_reader :predicates
def initialize(*predicates)
@predicates = predicates
end
# Build a Polyadic predicate based on:
# * <tt>operator</tt> - The Predicate subclass that defines the type of operation
# (LessThan, Equality, etc)
# * <tt>operand1</tt> - The left-hand operand (normally an Arel::Attribute)
# * <tt>additional_operands</tt> - All possible right-hand operands
def self.build(operator, operand1, *additional_operands)
new(
*additional_operands.uniq.map do |operand|
operator.new(operand1, operand)
end
)
end
def ==(other)
super || predicates == other.predicates
end
def bind(relation)
self.class.new(
*predicates.map {|p| p.find_correlate_in(relation)}
)
end
def eval(row)
predicates.send(compounder) do |operation|
operation.eval(row)
end
end
def to_sql(formatter = nil)
"(" +
predicates.map {|p| p.to_sql(formatter)}.join(" #{predicate_sql} ") +
")"
end
end
class Any < Polyadic
def complement
All.new(*predicates.map {|p| p.complement})
end
def compounder; :any? end
def predicate_sql; "OR" end
end
class All < Polyadic
def complement
Any.new(*predicates.map {|p| p.complement})
end
def compounder; :all? end
def predicate_sql; "AND" end
end
class Unary < Predicate
attr_reader :operand
def initialize operand
@operand = operand
end
def bind(relation)
self.class.new(operand.find_correlate_in(relation))
end
def == other
super || self.class === other && operand == other.operand
end
def eval(row)
operand.eval(row).send(operator)
end
def to_sql(formatter = nil)
"#{predicate_sql} (#{operand.to_sql(formatter)})"
end
end
class Not < Unary
def complement
operand
end
def eval(row)
!operand.eval(row)
end
def predicate_sql; "NOT" end
end
class Binary < Unary
attr_reader :operand2
alias :operand1 :operand
def initialize left, right
super(left)
@operand2 = right
end
def ==(other)
super && @operand2 == other.operand2
end
def bind(relation)
self.class.new(operand1.find_correlate_in(relation), operand2.find_correlate_in(relation))
end
def eval(row)
operand1.eval(row).send(operator, operand2.eval(row))
end
def to_sql(formatter = nil)
"#{operand1.to_sql} #{predicate_sql} #{operand1.format(operand2)}"
end
alias :value :to_sql
end
class CompoundPredicate < Binary
def eval(row)
eval "operand1.eval(row) #{operator} operand2.eval(row)"
end
def to_sql(formatter = nil)
"(#{operand1.to_sql(formatter)} #{predicate_sql} #{operand2.to_sql(formatter)})"
end
end
class And < CompoundPredicate
def complement
Or.new(operand1.complement, operand2.complement)
end
def operator; :and end
def predicate_sql; "AND" end
end
class Or < CompoundPredicate
def complement
And.new(operand1.complement, operand2.complement)
end
def operator; :or end
def predicate_sql; "OR" end
end
class Equality < Binary
def ==(other)
self.class === other and
((operand1 == other.operand1 and operand2 == other.operand2) or
(operand1 == other.operand2 and operand2 == other.operand1))
end
def complement
Inequality.new(operand1, operand2)
end
def operator; :== end
def predicate_sql
operand2.equality_predicate_sql
end
end
class Inequality < Equality
def complement
Equality.new(operand1, operand2)
end
def operator; :"!=" end
def eval(row)
operand1.eval(row) != operand2.eval(row)
end
def predicate_sql
operand2.inequality_predicate_sql
end
end
class GreaterThanOrEqualTo < Binary
def complement
LessThan.new(operand1, operand2)
end
def operator; :>= end
def predicate_sql; '>=' end
end
class GreaterThan < Binary
def complement
LessThanOrEqualTo.new(operand1, operand2)
end
def operator; :> end
def predicate_sql; '>' end
end
class LessThanOrEqualTo < Binary
def complement
GreaterThan.new(operand1, operand2)
end
def operator; :<= end
def predicate_sql; '<=' end
end
class LessThan < Binary
def complement
GreaterThanOrEqualTo.new(operand1, operand2)
end
def operator; :< end
def predicate_sql; '<' end
end
class Match < Binary
def complement
NotMatch.new(operand1, operand2)
end
def operator; :=~ end
def predicate_sql; 'LIKE' end
end
class NotMatch < Binary
def complement
Match.new(operand1, operand2)
end
def eval(row)
operand1.eval(row) !~ operand2.eval(row)
end
def predicate_sql; 'NOT LIKE' end
end
class In < Binary
def complement
NotIn.new(operand1, operand2)
end
def eval(row)
operand2.eval(row).include?(operand1.eval(row))
end
def to_sql(formatter = nil)
if operand2.is_a?(Range) && operand2.exclude_end?
GreaterThanOrEqualTo.new(operand1, operand2.begin).and(
LessThan.new(operand1, operand2.end)
).to_sql(formatter)
else
super
end
end
def predicate_sql; operand2.inclusion_predicate_sql end
end
class NotIn < Binary
def complement
In.new(operand1, operand2)
end
def eval(row)
!(operand2.eval(row).include?(operand1.eval(row)))
end
def predicate_sql; operand2.exclusion_predicate_sql end
end
end
end
|
