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
307
308
309
310
311
312
313
314
|
require 'enumerator'
module ActiveRecord
# = Active Record Through Association Scope
module Associations
module ThroughAssociationScope
protected
def construct_find_scope
{
:conditions => construct_conditions,
:joins => construct_joins,
:include => @reflection.options[:include] || @reflection.source_reflection.options[:include],
:select => construct_select,
:order => @reflection.options[:order],
:limit => @reflection.options[:limit],
:readonly => @reflection.options[:readonly]
}
end
def construct_create_scope
@reflection.nested? ? {} : construct_owner_attributes(@reflection)
end
# Build SQL conditions from attributes, qualified by table name.
# TODO: Conditions on joins
def construct_conditions
reflection = @reflection.through_reflection_chain.last
if reflection.macro == :has_and_belongs_to_many
table_alias = table_aliases[reflection].first
else
table_alias = table_aliases[reflection]
end
conditions = construct_quoted_owner_attributes(reflection).map do |attr, value|
"#{table_alias}.#{attr} = #{value}"
end
conditions << sql_conditions if sql_conditions
"(" + conditions.join(') AND (') + ")"
end
# Associate attributes pointing to owner, quoted.
def construct_quoted_owner_attributes(reflection)
if as = reflection.options[:as]
{ "#{as}_id" => owner_quoted_id,
"#{as}_type" => reflection.klass.quote_value(
@owner.class.base_class.name.to_s,
reflection.klass.columns_hash["#{as}_type"]) }
elsif reflection.macro == :belongs_to
{ reflection.klass.primary_key => @owner.class.quote_value(@owner[reflection.primary_key_name]) }
else
{ reflection.primary_key_name => owner_quoted_id }
end
end
def construct_from
@reflection.table_name
end
def construct_select(custom_select = nil)
distinct = "DISTINCT " if @reflection.options[:uniq]
selected = custom_select || @reflection.options[:select] || "#{distinct}#{@reflection.quoted_table_name}.*"
end
def construct_joins(custom_joins = nil)
# p @reflection.through_reflection_chain
"#{construct_through_joins} #{@reflection.options[:joins]} #{custom_joins}"
end
def construct_through_joins
joins = []
# Iterate over each pair in the through reflection chain, joining them together
@reflection.through_reflection_chain.each_cons(2) do |left, right|
right_table_and_alias = table_name_and_alias(right.quoted_table_name, table_aliases[right])
if left.source_reflection.nil?
# TODO: Perhaps need to pay attention to left.options[:primary_key] and
# left.options[:foreign_key] in places here
case left.macro
when :belongs_to
joins << inner_join_sql(
right_table_and_alias,
table_aliases[left], left.klass.primary_key,
table_aliases[right], left.primary_key_name
)
when :has_many, :has_one
joins << inner_join_sql(
right_table_and_alias,
table_aliases[left], left.primary_key_name,
table_aliases[right], right.klass.primary_key,
polymorphic_conditions(left, left)
)
when :has_and_belongs_to_many
joins << inner_join_sql(
right_table_and_alias,
table_aliases[left].first, left.primary_key_name,
table_aliases[right], right.klass.primary_key
)
end
else
case left.source_reflection.macro
when :belongs_to
joins << inner_join_sql(
right_table_and_alias,
table_aliases[left], left.klass.primary_key,
table_aliases[right], left.source_reflection.primary_key_name,
source_type_conditions(left)
)
when :has_many, :has_one
if right.macro == :has_and_belongs_to_many
join_table, right_table = table_aliases[right]
right_table_and_alias = table_name_and_alias(right.quoted_table_name, right_table)
else
right_table = table_aliases[right]
end
joins << inner_join_sql(
right_table_and_alias,
table_aliases[left], left.source_reflection.primary_key_name,
right_table, right.klass.primary_key,
polymorphic_conditions(left, left.source_reflection)
)
if right.macro == :has_and_belongs_to_many
joins << inner_join_sql(
table_name_and_alias(
quote_table_name(right.options[:join_table]),
join_table
),
right_table, right.klass.primary_key,
join_table, right.association_foreign_key
)
end
when :has_and_belongs_to_many
join_table, left_table = table_aliases[left]
joins << inner_join_sql(
table_name_and_alias(
quote_table_name(left.source_reflection.options[:join_table]),
join_table
),
left_table, left.klass.primary_key,
join_table, left.source_reflection.association_foreign_key
)
joins << inner_join_sql(
right_table_and_alias,
join_table, left.source_reflection.primary_key_name,
table_aliases[right], right.klass.primary_key
)
end
end
end
joins.join(" ")
end
def alias_tracker
@alias_tracker ||= AliasTracker.new
end
def table_aliases
@table_aliases ||= begin
@reflection.through_reflection_chain.inject({}) do |aliases, reflection|
table_alias = quote_table_name(alias_tracker.aliased_name_for(
reflection.table_name,
table_alias_for(reflection, reflection != @reflection)
))
if reflection.macro == :has_and_belongs_to_many ||
(reflection.source_reflection &&
reflection.source_reflection.macro == :has_and_belongs_to_many)
join_table_alias = quote_table_name(alias_tracker.aliased_name_for(
(reflection.source_reflection || reflection).options[:join_table],
table_alias_for(reflection, true)
))
aliases[reflection] = [join_table_alias, table_alias]
else
aliases[reflection] = table_alias
end
aliases
end
end
end
def table_alias_for(reflection, join = false)
name = alias_tracker.pluralize(reflection.name)
name << "_#{@reflection.name}"
name << "_join" if join
name
end
def quote_table_name(table_name)
@reflection.klass.connection.quote_table_name(table_name)
end
def table_name_and_alias(table_name, table_alias)
"#{table_name} #{table_alias if table_alias != table_name}".strip
end
def inner_join_sql(table, on_left_table, on_left_key, on_right_table, on_right_key, conds = nil)
"INNER JOIN %s ON %s.%s = %s.%s %s" % [
table,
on_left_table, on_left_key,
on_right_table, on_right_key,
conds
]
end
def polymorphic_conditions(reflection, polymorphic_reflection)
if polymorphic_reflection.options[:as]
"AND %s.%s = %s" % [
table_aliases[reflection], "#{polymorphic_reflection.options[:as]}_type",
@owner.class.quote_value(polymorphic_reflection.active_record.base_class.name)
]
end
end
def source_type_conditions(reflection)
if reflection.options[:source_type]
"AND %s.%s = %s" % [
table_aliases[reflection.through_reflection],
reflection.source_reflection.options[:foreign_type].to_s,
@owner.class.quote_value(reflection.options[:source_type])
]
end
end
# Construct attributes for associate pointing to owner.
def construct_owner_attributes(reflection)
if as = reflection.options[:as]
{ "#{as}_id" => @owner.id,
"#{as}_type" => @owner.class.base_class.name.to_s }
else
{ reflection.primary_key_name => @owner.id }
end
end
# Construct attributes for :through pointing to owner and associate.
def construct_join_attributes(associate)
# TODO: revisit this to allow it for deletion, supposing dependent option is supported
raise ActiveRecord::HasManyThroughCantAssociateThroughHasOneOrManyReflection.new(@owner, @reflection) if [:has_one, :has_many].include?(@reflection.source_reflection.macro)
join_attributes = construct_owner_attributes(@reflection.through_reflection).merge(@reflection.source_reflection.primary_key_name => associate.id)
if @reflection.options[:source_type]
join_attributes.merge!(@reflection.source_reflection.options[:foreign_type] => associate.class.base_class.name.to_s)
end
if @reflection.through_reflection.options[:conditions].is_a?(Hash)
join_attributes.merge!(@reflection.through_reflection.options[:conditions])
end
join_attributes
end
def conditions
@conditions = build_conditions unless defined?(@conditions)
@conditions
end
def build_conditions
association_conditions = @reflection.options[:conditions]
through_conditions = build_through_conditions
source_conditions = @reflection.source_reflection.options[:conditions]
uses_sti = !@reflection.through_reflection.klass.descends_from_active_record?
if association_conditions || through_conditions || source_conditions || uses_sti
all = []
[association_conditions, source_conditions].each do |conditions|
all << interpolate_sql(sanitize_sql(conditions)) if conditions
end
all << through_conditions if through_conditions
all << build_sti_condition if uses_sti
all.map { |sql| "(#{sql})" } * ' AND '
end
end
def build_through_conditions
conditions = @reflection.through_reflection.options[:conditions]
if conditions.is_a?(Hash)
interpolate_sql(@reflection.through_reflection.klass.send(:sanitize_sql, conditions)).gsub(
@reflection.quoted_table_name,
@reflection.through_reflection.quoted_table_name)
elsif conditions
interpolate_sql(sanitize_sql(conditions))
end
end
def build_sti_condition
@reflection.through_reflection.klass.send(:type_condition).to_sql
end
alias_method :sql_conditions, :conditions
def ensure_not_nested
if @reflection.nested?
raise HasManyThroughNestedAssociationsAreReadonly.new(@owner, @reflection)
end
end
end
end
end
|