Module: JdbcSpec::PostgreSQL

Defined in:
lib/jdbc_adapter/jdbc_postgre.rb

Defined Under Namespace

Modules: Column

Class Method Summary collapse

Instance Method Summary collapse

Class Method Details

.adapter_matcher(name) ⇒ Object 



29
30
31
 
# File 'lib/jdbc_adapter/jdbc_postgre.rb', line 29

def self.adapter_matcher(name, *)
  name =~ /postgre/i ? self : false
end

.column_selector ⇒ Object 



33
34
35
 
# File 'lib/jdbc_adapter/jdbc_postgre.rb', line 33

def self.column_selector
  [/postgre/i, lambda {|cfg,col| col.extend(::JdbcSpec::PostgreSQL::Column)}]
end

.extended(mod) ⇒ Object 



23
24
25
26
27
 
# File 'lib/jdbc_adapter/jdbc_postgre.rb', line 23

def self.extended(mod)
  mod.class.class_eval do
    alias_chained_method :insert, :query_dirty, :insert
  end
end

.jdbc_connection_class ⇒ Object 



37
38
39
 
# File 'lib/jdbc_adapter/jdbc_postgre.rb', line 37

def self.jdbc_connection_class
  ::ActiveRecord::ConnectionAdapters::PostgresJdbcConnection
end

Instance Method Details

#_execute(sql, name = nil) ⇒ Object 



384
385
386
387
388
389
390
391
 
# File 'lib/jdbc_adapter/jdbc_postgre.rb', line 384

def _execute(sql, name = nil)
    case sql.strip
    when /\A\(?\s*(select|show)/i then
      @connection.execute_query(sql)
    else
      @connection.execute_update(sql)
    end
end

#adapter_name ⇒ Object

:nodoc:



98
99
100
 
# File 'lib/jdbc_adapter/jdbc_postgre.rb', line 98

def adapter_name #:nodoc:
  'PostgreSQL'
end

#add_column(table_name, column_name, type, options = {}) ⇒ Object 



471
472
473
474
475
476
477
478
 
# File 'lib/jdbc_adapter/jdbc_postgre.rb', line 471

def add_column(table_name, column_name, type, options = {})
  execute("ALTER TABLE #{quote_table_name(table_name)} ADD #{quote_column_name(column_name)} #{type_to_sql(type, options[:limit])}")
  change_column_default(table_name, column_name, options[:default]) unless options[:default].nil?
  if options[:null] == false
    execute("UPDATE #{quote_table_name(table_name)} SET #{quote_column_name(column_name)} = '#{options[:default]}'") if options[:default]
    execute("ALTER TABLE #{quote_table_name(table_name)} ALTER #{quote_column_name(column_name)} SET NOT NULL")
  end
end

#add_order_by_for_association_limiting!(sql, options) ⇒ Object

ORDER BY clause for the passed order option.

PostgreSQL does not allow arbitrary ordering when using DISTINCT ON, so we work around this by wrapping the sql as a sub-select and ordering in that query.



418
419
420
421
422
423
424
425
426
 
# File 'lib/jdbc_adapter/jdbc_postgre.rb', line 418

def add_order_by_for_association_limiting!(sql, options)
  return sql if options[:order].blank?

  order = options[:order].split(',').collect { |s| s.strip }.reject(&:blank?)
  order.map! { |s| 'DESC' if s =~ /\bdesc$/i }
  order = order.zip((0...order.size).to_a).map { |s,i| "id_list.alias_#{i} #{s}" }.join(', ')

  sql.replace "SELECT * FROM (#{sql}) AS id_list ORDER BY #{order}"
end

#all_schemas ⇒ Object 



347
348
349
 
# File 'lib/jdbc_adapter/jdbc_postgre.rb', line 347

def all_schemas
  select('select nspname from pg_namespace').map {|r| r["nspname"] }
end

#change_column(table_name, column_name, type, options = {}) ⇒ Object

:nodoc:



480
481
482
483
484
485
486
487
488
489
490
491
492
493
 
# File 'lib/jdbc_adapter/jdbc_postgre.rb', line 480

def change_column(table_name, column_name, type, options = {}) #:nodoc:
  begin
    execute "ALTER TABLE #{quote_table_name(table_name)} ALTER #{quote_column_name(column_name)} TYPE #{type_to_sql(type, options[:limit])}"
  rescue ActiveRecord::StatementInvalid
    # This is PG7, so we use a more arcane way of doing it.
    begin_db_transaction
    add_column(table_name, "#{column_name}_ar_tmp", type, options)
    execute "UPDATE #{table_name} SET #{column_name}_ar_tmp = CAST(#{column_name} AS #{type_to_sql(type, options[:limit])})"
    remove_column(table_name, column_name)
    rename_column(table_name, "#{column_name}_ar_tmp", column_name)
    commit_db_transaction
  end
  change_column_default(table_name, column_name, options[:default]) unless options[:default].nil?
end

#change_column_default(table_name, column_name, default) ⇒ Object

:nodoc:



495
496
497
 
# File 'lib/jdbc_adapter/jdbc_postgre.rb', line 495

def change_column_default(table_name, column_name, default) #:nodoc:
  execute "ALTER TABLE #{quote_table_name(table_name)} ALTER COLUMN #{quote_column_name(column_name)} SET DEFAULT '#{default}'"
end

#change_column_null(table_name, column_name, null, default = nil) ⇒ Object 



499
500
501
502
503
504
 
# File 'lib/jdbc_adapter/jdbc_postgre.rb', line 499

def change_column_null(table_name, column_name, null, default = nil)
  unless null || default.nil?
    execute("UPDATE #{quote_table_name(table_name)} SET #{quote_column_name(column_name)}=#{quote(default)} WHERE #{quote_column_name(column_name)} IS NULL")
  end
  execute("ALTER TABLE #{quote_table_name(table_name)} ALTER #{quote_column_name(column_name)} #{null ? 'DROP' : 'SET'} NOT NULL")
end

#columns(table_name, name = nil) ⇒ Object 



278
279
280
281
282
283
284
285
286
 
# File 'lib/jdbc_adapter/jdbc_postgre.rb', line 278

def columns(table_name, name=nil)
  schema_name = @config[:schema_search_path]
  if table_name =~ /\./
    parts = table_name.split(/\./)
    table_name = parts.pop
    schema_name = parts.join(".")
  end
  @connection.columns_internal(table_name, name, schema_name)
end

#create_database(name, options = {}) ⇒ Object 



331
332
333
 
# File 'lib/jdbc_adapter/jdbc_postgre.rb', line 331

def create_database(name, options = {})
  execute "CREATE DATABASE \"#{name}\" ENCODING='#{options[:encoding] || 'utf8'}'"
end

#create_savepoint ⇒ Object 



147
148
149
 
# File 'lib/jdbc_adapter/jdbc_postgre.rb', line 147

def create_savepoint
  execute("SAVEPOINT #{current_savepoint_name}")
end

#create_schema(schema_name, pg_username) ⇒ Object 



339
340
341
 
# File 'lib/jdbc_adapter/jdbc_postgre.rb', line 339

def create_schema(schema_name, pg_username)
  execute("CREATE SCHEMA \"#{schema_name}\" AUTHORIZATION \"#{pg_username}\"")
end

#default_sequence_name(table_name, pk = nil) ⇒ Object 



165
166
167
168
 
# File 'lib/jdbc_adapter/jdbc_postgre.rb', line 165

def default_sequence_name(table_name, pk = nil)
  default_pk, default_seq = pk_and_sequence_for(table_name)
  default_seq || "#{table_name}_#{pk || default_pk || 'id'}_seq"
end

#disable_referential_integrity(&block) ⇒ Object

:nodoc:



460
461
462
463
464
465
 
# File 'lib/jdbc_adapter/jdbc_postgre.rb', line 460

def disable_referential_integrity(&block) #:nodoc:
  execute(tables.collect { |name| "ALTER TABLE #{quote_table_name(name)} DISABLE TRIGGER ALL" }.join(";"))
  yield
ensure
  execute(tables.collect { |name| "ALTER TABLE #{quote_table_name(name)} ENABLE TRIGGER ALL" }.join(";"))
end

#distinct(columns, order_by) ⇒ Object

SELECT DISTINCT clause for a given set of columns and a given ORDER BY clause.

PostgreSQL requires the ORDER BY columns in the select list for distinct queries, and requires that the ORDER BY include the distinct column.

distinct("posts.id", "posts.created_at desc")



399
400
401
402
403
404
405
406
407
408
409
410
411
412
 
# File 'lib/jdbc_adapter/jdbc_postgre.rb', line 399

def distinct(columns, order_by)
  return "DISTINCT #{columns}" if order_by.blank?

  # construct a clean list of column names from the ORDER BY clause, removing
  # any asc/desc modifiers
  order_columns = order_by.split(',').collect { |s| s.split.first }
  order_columns.delete_if(&:blank?)
  order_columns = order_columns.zip((0...order_columns.size).to_a).map { |s,i| "#{s} AS alias_#{i}" }

  # return a DISTINCT ON() clause that's distinct on the columns we want but includes
  # all the required columns for the ORDER BY to work properly
  sql = "DISTINCT ON (#{columns}) #{columns}, "
  sql << order_columns * ', '
end

#drop_database(name) ⇒ Object 



335
336
337
 
# File 'lib/jdbc_adapter/jdbc_postgre.rb', line 335

def drop_database(name)
  execute "DROP DATABASE \"#{name}\""
end

#drop_schema(schema_name) ⇒ Object 



343
344
345
 
# File 'lib/jdbc_adapter/jdbc_postgre.rb', line 343

def drop_schema(schema_name)
  execute("DROP SCHEMA \"#{schema_name}\"")
end

#escape_bytea(s) ⇒ Object 



440
441
442
443
444
445
446
 
# File 'lib/jdbc_adapter/jdbc_postgre.rb', line 440

def escape_bytea(s)
  if s
    result = ''
    s.each_byte { |c| result << sprintf('\\\\%03o', c) }
    result
  end
end

#indexes(table_name, name = nil) ⇒ Object

From postgresql_adapter.rb



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
315
316
317
318
319
320
 
# File 'lib/jdbc_adapter/jdbc_postgre.rb', line 289

def indexes(table_name, name = nil)
  result = select_rows(<<-SQL, name)
    SELECT i.relname, d.indisunique, a.attname
      FROM pg_class t, pg_class i, pg_index d, pg_attribute a
     WHERE i.relkind = 'i'
       AND d.indexrelid = i.oid
       AND d.indisprimary = 'f'
       AND t.oid = d.indrelid
       AND t.relname = '#{table_name}'
       AND a.attrelid = t.oid
       AND ( d.indkey[0]=a.attnum OR d.indkey[1]=a.attnum
          OR d.indkey[2]=a.attnum OR d.indkey[3]=a.attnum
          OR d.indkey[4]=a.attnum OR d.indkey[5]=a.attnum
          OR d.indkey[6]=a.attnum OR d.indkey[7]=a.attnum
          OR d.indkey[8]=a.attnum OR d.indkey[9]=a.attnum )
    ORDER BY i.relname
  SQL

  current_index = nil
  indexes = []

  result.each do |row|
    if current_index != row[0]
      indexes << ::ActiveRecord::ConnectionAdapters::IndexDefinition.new(table_name, row[0], row[1] == "t", [])
      current_index = row[0]
    end

    indexes.last.columns << row[2]
  end

  indexes
end

#insert(sql, name = nil, pk = nil, id_value = nil, sequence_name = nil) ⇒ Object 



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
 
# File 'lib/jdbc_adapter/jdbc_postgre.rb', line 244

def insert(sql, name = nil, pk = nil, id_value = nil, sequence_name = nil)
  # Extract the table from the insert sql. Yuck.
  table = sql.split(" ", 4)[2].gsub('"', '')

  # Try an insert with 'returning id' if available (PG >= 8.2)
  if supports_insert_with_returning? && id_value.nil?
    pk, sequence_name = *pk_and_sequence_for(table) unless pk
    if pk
      id_value = select_value("#{sql} RETURNING #{quote_column_name(pk)}")
      clear_query_cache #FIXME: Why now?
      return id_value
    end
  end

  # Otherwise, plain insert
  execute(sql, name)

  # Don't need to look up id_value if we already have it.
  # (and can't in case of non-sequence PK)
  unless id_value
    # If neither pk nor sequence name is given, look them up.
    unless pk || sequence_name
      pk, sequence_name = *pk_and_sequence_for(table)
    end

    # If a pk is given, fallback to default sequence name.
    # Don't fetch last insert id for a table without a pk.
    if pk && sequence_name ||= default_sequence_name(table, pk)
      id_value = last_insert_id(table, sequence_name)
    end
  end
  id_value
end

#last_insert_id(table, sequence_name) ⇒ Object 



322
323
324
 
# File 'lib/jdbc_adapter/jdbc_postgre.rb', line 322

def last_insert_id(table, sequence_name)
  Integer(select_value("SELECT currval('#{sequence_name}')"))
end

#modify_types(tp) ⇒ Object 



90
91
92
93
94
95
96
 
# File 'lib/jdbc_adapter/jdbc_postgre.rb', line 90

def modify_types(tp)
  tp[:primary_key] = "serial primary key"
  tp[:string][:limit] = 255
  tp[:integer][:limit] = nil
  tp[:boolean][:limit] = nil
  tp
end

#pk_and_sequence_for(table) ⇒ Object

Find a table’s primary key and sequence.



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
 
# File 'lib/jdbc_adapter/jdbc_postgre.rb', line 197

def pk_and_sequence_for(table) #:nodoc:
  # First try looking for a sequence with a dependency on the
  # given table's primary key.
  result = select(<<-end_sql, 'PK and serial sequence')[0]
      SELECT attr.attname, seq.relname
      FROM pg_class      seq,
           pg_attribute  attr,
           pg_depend     dep,
           pg_namespace  name,
           pg_constraint cons
      WHERE seq.oid           = dep.objid
        AND seq.relkind       = 'S'
        AND attr.attrelid     = dep.refobjid
        AND attr.attnum       = dep.refobjsubid
        AND attr.attrelid     = cons.conrelid
        AND attr.attnum       = cons.conkey[1]
        AND cons.contype      = 'p'
        AND dep.refobjid      = '#{table}'::regclass
    end_sql

  if result.nil? or result.empty?
    # If that fails, try parsing the primary key's default value.
    # Support the 7.x and 8.0 nextval('foo'::text) as well as
    # the 8.1+ nextval('foo'::regclass).
    result = select(<<-end_sql, 'PK and custom sequence')[0]
        SELECT attr.attname,
          CASE
            WHEN split_part(def.adsrc, '''', 2) ~ '.' THEN
              substr(split_part(def.adsrc, '''', 2),
                     strpos(split_part(def.adsrc, '''', 2), '.')+1)
            ELSE split_part(def.adsrc, '''', 2)
          END as relname
        FROM pg_class       t
        JOIN pg_attribute   attr ON (t.oid = attrelid)
        JOIN pg_attrdef     def  ON (adrelid = attrelid AND adnum = attnum)
        JOIN pg_constraint  cons ON (conrelid = adrelid AND adnum = conkey[1])
        WHERE t.oid = '#{table}'::regclass
          AND cons.contype = 'p'
          AND def.adsrc ~* 'nextval'
      end_sql
  end

  [result["attname"], result["relname"]]
rescue
  nil
end

#postgresql_version ⇒ Object 



102
103
104
105
106
107
108
109
110
111
112
 
# File 'lib/jdbc_adapter/jdbc_postgre.rb', line 102

def postgresql_version
  @postgresql_version ||=
    begin
      value = select_value('SELECT version()')
      if value =~ /PostgreSQL (\d+)\.(\d+)\.(\d+)/
        ($1.to_i * 10000) + ($2.to_i * 100) + $3.to_i
      else
        0
      end
    end
end

#primary_key(table) ⇒ Object 



351
352
353
354
 
# File 'lib/jdbc_adapter/jdbc_postgre.rb', line 351

def primary_key(table)
  pk_and_sequence = pk_and_sequence_for(table)
  pk_and_sequence && pk_and_sequence.first
end

#quote(value, column = nil) ⇒ Object 



428
429
430
431
432
433
434
435
436
437
438
 
# File 'lib/jdbc_adapter/jdbc_postgre.rb', line 428

def quote(value, column = nil)
  return value.quoted_id if value.respond_to?(:quoted_id)

  if value.kind_of?(String) && column && column.type == :binary
    "'#{escape_bytea(value)}'"
  elsif column && column.type == :primary_key
    return value.to_s
  else
    super
  end
end

#quote_column_name(name) ⇒ Object 



448
449
450
 
# File 'lib/jdbc_adapter/jdbc_postgre.rb', line 448

def quote_column_name(name)
  %("#{name}")
end

#quote_regclass(table_name) ⇒ Object 



190
191
192
193
194
 
# File 'lib/jdbc_adapter/jdbc_postgre.rb', line 190

def quote_regclass(table_name)
  table_name.to_s.split('.').map do |part| 
    part =~ /".*"/i ? part : quote_table_name(part)
  end.join('.')  
end

#quoted_date(value) ⇒ Object

:nodoc:



452
453
454
455
456
457
458
 
# File 'lib/jdbc_adapter/jdbc_postgre.rb', line 452

def quoted_date(value) #:nodoc:
  if value.acts_like?(:time) && value.respond_to?(:usec)
    "#{super}.#{sprintf("%06d", value.usec)}"
  else
    super
  end
end

#recreate_database(name) ⇒ Object 



326
327
328
329
 
# File 'lib/jdbc_adapter/jdbc_postgre.rb', line 326

def recreate_database(name)
  drop_database(name)
  create_database(name)
end

#release_savepoint ⇒ Object 



155
156
157
 
# File 'lib/jdbc_adapter/jdbc_postgre.rb', line 155

def release_savepoint
  execute("RELEASE SAVEPOINT #{current_savepoint_name}")
end

#remove_index(table_name, options) ⇒ Object

:nodoc:



510
511
512
 
# File 'lib/jdbc_adapter/jdbc_postgre.rb', line 510

def remove_index(table_name, options) #:nodoc:
  execute "DROP INDEX #{index_name(table_name, options)}"
end

#rename_column(table_name, column_name, new_column_name) ⇒ Object

:nodoc:



506
507
508
 
# File 'lib/jdbc_adapter/jdbc_postgre.rb', line 506

def rename_column(table_name, column_name, new_column_name) #:nodoc:
  execute "ALTER TABLE #{quote_table_name(table_name)} RENAME COLUMN #{quote_column_name(column_name)} TO #{quote_column_name(new_column_name)}"
end

#rename_table(name, new_name) ⇒ Object 



467
468
469
 
# File 'lib/jdbc_adapter/jdbc_postgre.rb', line 467

def rename_table(name, new_name)
  execute "ALTER TABLE #{name} RENAME TO #{new_name}"
end

#reset_pk_sequence!(table, pk = nil, sequence = nil) ⇒ Object

Resets sequence to the max value of the table’s pk if present.



171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
 
# File 'lib/jdbc_adapter/jdbc_postgre.rb', line 171

def reset_pk_sequence!(table, pk = nil, sequence = nil) #:nodoc:
  unless pk and sequence
    default_pk, default_sequence = pk_and_sequence_for(table)
    pk ||= default_pk
    sequence ||= default_sequence
  end
  if pk
    if sequence
      quoted_sequence = quote_column_name(sequence)

      select_value <<-end_sql, 'Reset sequence'
          SELECT setval('#{quoted_sequence}', (SELECT COALESCE(MAX(#{quote_column_name pk})+(SELECT increment_by FROM #{quoted_sequence}), (SELECT min_value FROM #{quoted_sequence})) FROM #{quote_table_name(table)}), false)
        end_sql
    else
      @logger.warn "#{table} has primary key #{pk} with no default sequence" if @logger
    end
  end
end

#rollback_to_savepoint ⇒ Object 



151
152
153
 
# File 'lib/jdbc_adapter/jdbc_postgre.rb', line 151

def rollback_to_savepoint
  execute("ROLLBACK TO SAVEPOINT #{current_savepoint_name}")
end

#structure_dump ⇒ Object 



356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
 
# File 'lib/jdbc_adapter/jdbc_postgre.rb', line 356

def structure_dump
  database = @config[:database]
  if database.nil?
    if @config[:url] =~ /\/([^\/]*)$/
      database = $1
    else
      raise "Could not figure out what database this url is for #{@config["url"]}"
    end
  end

  ENV['PGHOST']     = @config[:host] if @config[:host]
  ENV['PGPORT']     = @config[:port].to_s if @config[:port]
  ENV['PGPASSWORD'] = @config[:password].to_s if @config[:password]
  search_path = @config[:schema_search_path]
  search_path = "--schema=#{search_path}" if search_path

  @connection.connection.close
  begin
    definition = `pg_dump -i -U "#{@config[:username]}" -s -x -O #{search_path} #{database}`
    raise "Error dumping database" if $?.exitstatus == 1

    # need to patch away any references to SQL_ASCII as it breaks the JDBC driver
    definition.gsub(/SQL_ASCII/, 'UNICODE')
  ensure
    reconnect!
  end
end

#supports_ddl_transactions? ⇒ Boolean

Returns:

  • (Boolean) 


139
140
141
 
# File 'lib/jdbc_adapter/jdbc_postgre.rb', line 139

def supports_ddl_transactions?
  true
end

#supports_insert_with_returning? ⇒ Boolean

Returns:

  • (Boolean) 


135
136
137
 
# File 'lib/jdbc_adapter/jdbc_postgre.rb', line 135

def supports_insert_with_returning?
  postgresql_version >= 80200
end

#supports_migrations? ⇒ Boolean

Does PostgreSQL support migrations?

Returns:

  • (Boolean) 


115
116
117
 
# File 'lib/jdbc_adapter/jdbc_postgre.rb', line 115

def supports_migrations?
  true
end

#supports_savepoints? ⇒ Boolean

Returns:

  • (Boolean) 


143
144
145
 
# File 'lib/jdbc_adapter/jdbc_postgre.rb', line 143

def supports_savepoints?
  true
end

#supports_standard_conforming_strings? ⇒ Boolean

Does PostgreSQL support standard conforming strings?

Returns:

  • (Boolean) 


120
121
122
123
124
125
126
127
128
129
130
131
132
133
 
# File 'lib/jdbc_adapter/jdbc_postgre.rb', line 120

def supports_standard_conforming_strings?
  # Temporarily set the client message level above error to prevent unintentional
  # error messages in the logs when working on a PostgreSQL database server that
  # does not support standard conforming strings.
  client_min_messages_old = client_min_messages
  self.client_min_messages = 'panic'

  # postgres-pr does not raise an exception when client_min_messages is set higher
  # than error and "SHOW standard_conforming_strings" fails, but returns an empty
  # PGresult instead.
  has_support = select('SHOW standard_conforming_strings').to_a[0][0] rescue false
  self.client_min_messages = client_min_messages_old
  has_support
end

#table_alias_length ⇒ Object

Returns the configured supported identifier length supported by PostgreSQL, or report the default of 63 on PostgreSQL 7.x.



161
162
163
 
# File 'lib/jdbc_adapter/jdbc_postgre.rb', line 161

def table_alias_length
  @table_alias_length ||= (postgresql_version >= 80000 ? select('SHOW max_identifier_length').to_a[0][0].to_i : 63)
end

#tables ⇒ Object 



526
527
528
 
# File 'lib/jdbc_adapter/jdbc_postgre.rb', line 526

def tables
  @connection.tables(database_name, nil, nil, ["TABLE"])
end

#type_to_sql(type, limit = nil, precision = nil, scale = nil) ⇒ Object

:nodoc:



514
515
516
517
518
519
520
521
522
523
524
 
# File 'lib/jdbc_adapter/jdbc_postgre.rb', line 514

def type_to_sql(type, limit = nil, precision = nil, scale = nil) #:nodoc:
  return super unless type.to_s == 'integer'

  if limit.nil? || limit == 4
    'integer'
  elsif limit < 4
    'smallint'
  else
    'bigint'
  end
end