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
|
module Gitlab
module Database
# The max value of INTEGER type is the same between MySQL and PostgreSQL:
# https://www.postgresql.org/docs/9.2/static/datatype-numeric.html
# http://dev.mysql.com/doc/refman/5.7/en/integer-types.html
MAX_INT_VALUE = 2147483647
# The max value between MySQL's TIMESTAMP and PostgreSQL's timestampz:
# https://www.postgresql.org/docs/9.1/static/datatype-datetime.html
# https://dev.mysql.com/doc/refman/5.7/en/datetime.html
MAX_TIMESTAMP_VALUE = Time.at((1 << 31) - 1).freeze
def self.config
ActiveRecord::Base.configurations[Rails.env]
end
def self.username
config['username'] || ENV['USER']
end
def self.database_name
config['database']
end
def self.adapter_name
config['adapter']
end
def self.mysql?
adapter_name.casecmp('mysql2').zero?
end
def self.postgresql?
adapter_name.casecmp('postgresql').zero?
end
# Overridden in EE
def self.read_only?
false
end
def self.read_write?
!self.read_only?
end
def self.version
database_version.match(/\A(?:PostgreSQL |)([^\s]+).*\z/)[1]
end
def self.join_lateral_supported?
postgresql? && version.to_f >= 9.3
end
def self.replication_slots_supported?
postgresql? && version.to_f >= 9.4
end
def self.nulls_last_order(field, direction = 'ASC')
order = "#{field} #{direction}"
if postgresql?
order << ' NULLS LAST'
else
# `field IS NULL` will be `0` for non-NULL columns and `1` for NULL
# columns. In the (default) ascending order, `0` comes first.
order.prepend("#{field} IS NULL, ") if direction == 'ASC'
end
order
end
def self.nulls_first_order(field, direction = 'ASC')
order = "#{field} #{direction}"
if postgresql?
order << ' NULLS FIRST'
else
# `field IS NULL` will be `0` for non-NULL columns and `1` for NULL
# columns. In the (default) ascending order, `0` comes first.
order.prepend("#{field} IS NULL, ") if direction == 'DESC'
end
order
end
def self.random
postgresql? ? "RANDOM()" : "RAND()"
end
def self.true_value
if postgresql?
"'t'"
else
1
end
end
def self.false_value
if postgresql?
"'f'"
else
0
end
end
def self.with_connection_pool(pool_size)
pool = create_connection_pool(pool_size)
begin
yield(pool)
ensure
pool.disconnect!
end
end
# Bulk inserts a number of rows into a table, optionally returning their
# IDs.
#
# table - The name of the table to insert the rows into.
# rows - An Array of Hash instances, each mapping the columns to their
# values.
# return_ids - When set to true the return value will be an Array of IDs of
# the inserted rows, this only works on PostgreSQL.
# disable_quote - A key or an Array of keys to exclude from quoting (You
# become responsible for protection from SQL injection for
# these keys!)
def self.bulk_insert(table, rows, return_ids: false, disable_quote: [])
return if rows.empty?
keys = rows.first.keys
columns = keys.map { |key| connection.quote_column_name(key) }
return_ids = false if mysql?
disable_quote = Array(disable_quote).to_set
tuples = rows.map do |row|
keys.map do |k|
disable_quote.include?(k) ? row[k] : connection.quote(row[k])
end
end
sql = <<-EOF
INSERT INTO #{table} (#{columns.join(', ')})
VALUES #{tuples.map { |tuple| "(#{tuple.join(', ')})" }.join(', ')}
EOF
if return_ids
sql << 'RETURNING id'
end
result = connection.execute(sql)
if return_ids
result.values.map { |tuple| tuple[0].to_i }
else
[]
end
end
def self.sanitize_timestamp(timestamp)
MAX_TIMESTAMP_VALUE > timestamp ? timestamp : MAX_TIMESTAMP_VALUE.dup
end
# pool_size - The size of the DB pool.
# host - An optional host name to use instead of the default one.
def self.create_connection_pool(pool_size, host = nil)
# See activerecord-4.2.7.1/lib/active_record/connection_adapters/connection_specification.rb
env = Rails.env
original_config = ActiveRecord::Base.configurations
env_config = original_config[env].merge('pool' => pool_size)
env_config['host'] = host if host
config = original_config.merge(env => env_config)
spec =
ActiveRecord::
ConnectionAdapters::
ConnectionSpecification::Resolver.new(config).spec(env.to_sym)
ActiveRecord::ConnectionAdapters::ConnectionPool.new(spec)
end
def self.connection
ActiveRecord::Base.connection
end
def self.cached_column_exists?(table_name, column_name)
connection.schema_cache.columns_hash(table_name).has_key?(column_name.to_s)
end
private_class_method :connection
def self.database_version
row = connection.execute("SELECT VERSION()").first
if postgresql?
row['version']
else
row.first
end
end
private_class_method :database_version
end
end
|