Module: ActiveRecord::ConnectionAdapters::Redshift::SchemaStatements

Included in:
ActiveRecord::ConnectionAdapters::RedshiftAdapter
Defined in:
lib/active_record/connection_adapters/redshift/schema_statements.rb

Instance Method Summary collapse

Instance Method Details

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

Adds a new column to the named table. See TableDefinition#column for details of the options you can use.



390
391
392
393
 
# File 'lib/active_record/connection_adapters/redshift/schema_statements.rb', line 390

def add_column(table_name, column_name, type, options = {})
  clear_cache!
  super
end

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

:nodoc:



444
445
446
 
# File 'lib/active_record/connection_adapters/redshift/schema_statements.rb', line 444

def add_index(table_name, column_name, options = {}) #:nodoc:
  # ignore
end

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

Changes the column of a table.



396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
 
# File 'lib/active_record/connection_adapters/redshift/schema_statements.rb', line 396

def change_column(table_name, column_name, type, options = {})
  clear_cache!
  quoted_table_name = quote_table_name(table_name)
  sql_type = type_to_sql(type, options[:limit], options[:precision], options[:scale])
  sql_type << "[]" if options[:array]
  sql = "ALTER TABLE #{quoted_table_name} ALTER COLUMN #{quote_column_name(column_name)} TYPE #{sql_type}"
  sql << " USING #{options[:using]}" if options[:using]
  if options[:cast_as]
    sql << " USING CAST(#{quote_column_name(column_name)} AS #{type_to_sql(options[:cast_as], options[:limit], options[:precision], options[:scale])})"
  end
  execute sql

  change_column_default(table_name, column_name, options[:default]) if options_include_default?(options)
  change_column_null(table_name, column_name, options[:null], options[:default]) if options.key?(:null)
end

#change_column_default(table_name, column_name, default) ⇒ Object

Changes the default value of a table column.



413
414
415
416
417
418
419
420
421
422
423
424
425
426
 
# File 'lib/active_record/connection_adapters/redshift/schema_statements.rb', line 413

def change_column_default(table_name, column_name, default)
  clear_cache!
  column = column_for(table_name, column_name)
  return unless column

  alter_column_query = "ALTER TABLE #{quote_table_name(table_name)} ALTER COLUMN #{quote_column_name(column_name)} %s"
  if default.nil?
    # <tt>DEFAULT NULL</tt> results in the same behavior as <tt>DROP DEFAULT</tt>. However, PostgreSQL will
    # cast the default to the columns type, which leaves us with a default like "default NULL::character varying".
    execute alter_column_query % "DROP DEFAULT"
  else
    execute alter_column_query % "SET DEFAULT #{quote_default_value(default, column)}"
  end
end

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



428
429
430
431
432
433
434
435
 
# File 'lib/active_record/connection_adapters/redshift/schema_statements.rb', line 428

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

#client_min_messages ⇒ Object

Returns the current client message level.



230
231
232
 
# File 'lib/active_record/connection_adapters/redshift/schema_statements.rb', line 230

def client_min_messages
  query('SHOW client_min_messages', 'SCHEMA')[0][0]
end

#client_min_messages=(level) ⇒ Object

Set the client message level.



235
236
237
238
 
# File 'lib/active_record/connection_adapters/redshift/schema_statements.rb', line 235

def client_min_messages=(level)
  # can't set client_min_messages in redshift
  # execute("SET client_min_messages TO '#{level}'", 'SCHEMA')
end

#collation ⇒ Object

Returns the current database collation.



178
179
180
181
182
 
# File 'lib/active_record/connection_adapters/redshift/schema_statements.rb', line 178

def collation
  query("    SELECT pg_database.datcollate FROM pg_database WHERE pg_database.datname LIKE '\#{current_database}'\n  end_sql\nend\n", 'SCHEMA')[0][0]

#columns(table_name) ⇒ Object

Returns the list of all column definitions for a table.



145
146
147
148
149
150
151
152
153
 
# File 'lib/active_record/connection_adapters/redshift/schema_statements.rb', line 145

def columns(table_name)
  # Limit, precision, and scale are all handled by the superclass.
  column_definitions(table_name).map do |column_name, type, default, notnull, oid, fmod|
    oid = get_oid_type(oid.to_i, fmod.to_i, column_name, type)
    default_value = extract_value_from_default(oid, default)
    default_function = extract_default_function(default_value, default)
    new_column(column_name, default_value, oid, type, notnull == 'f', default_function)
  end
end

#columns_for_distinct(columns, orders) ⇒ Object

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



542
543
544
545
546
547
548
549
550
551
552
 
# File 'lib/active_record/connection_adapters/redshift/schema_statements.rb', line 542

def columns_for_distinct(columns, orders) #:nodoc:
  order_columns = orders.reject(&:blank?).map{ |s|
      # Convert Arel node to string
      s = s.to_sql unless s.is_a?(String)
      # Remove any ASC/DESC modifiers
      s.gsub(/\s+(?:ASC|DESC)\b/i, '')
       .gsub(/\s+NULLS\s+(?:FIRST|LAST)\b/i, '')
    }.reject(&:blank?).map.with_index { |column, i| "#{column} AS alias_#{i}" }

  [super, *order_columns].join(', ')
end

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

Create a new PostgreSQL database. Options include :owner, :encoding (defaults to utf8), :collation, :ctype, :tablespace, and :connection_limit (note that MySQL uses :charset while PostgreSQL uses :encoding).

Example:

create_database config[:database], config
create_database 'foo_development', encoding: 'unicode'



54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
 
# File 'lib/active_record/connection_adapters/redshift/schema_statements.rb', line 54

def create_database(name, options = {})
  options = { encoding: 'utf8' }.merge!(options.symbolize_keys)

  option_string = options.inject("") do |memo, (key, value)|
    memo += case key
    when :owner
      " OWNER = \"#{value}\""
    when :encoding
      " ENCODING = '#{value}'"
    when :collation
      " LC_COLLATE = '#{value}'"
    when :ctype
      " LC_CTYPE = '#{value}'"
    when :tablespace
      " TABLESPACE = \"#{value}\""
    when :connection_limit
      " CONNECTION LIMIT = #{value}"
    else
      ""
    end
  end

  execute "CREATE DATABASE #{quote_table_name(name)}#{option_string}"
end

#create_schema(schema_name) ⇒ Object

Creates a schema for the given schema name.



203
204
205
 
# File 'lib/active_record/connection_adapters/redshift/schema_statements.rb', line 203

def create_schema schema_name
  execute "CREATE SCHEMA #{schema_name}"
end

#ctype ⇒ Object

Returns the current database ctype.



185
186
187
188
189
 
# File 'lib/active_record/connection_adapters/redshift/schema_statements.rb', line 185

def ctype
  query("    SELECT pg_database.datctype FROM pg_database WHERE pg_database.datname LIKE '\#{current_database}'\n  end_sql\nend\n", 'SCHEMA')[0][0]

#current_database ⇒ Object

Returns the current database name.



160
161
162
 
# File 'lib/active_record/connection_adapters/redshift/schema_statements.rb', line 160

def current_database
  query('select current_database()', 'SCHEMA')[0][0]
end

#current_schema ⇒ Object

Returns the current schema name.



165
166
167
 
# File 'lib/active_record/connection_adapters/redshift/schema_statements.rb', line 165

def current_schema
  query('SELECT current_schema', 'SCHEMA')[0][0]
end

#default_sequence_name(table_name, pk = nil) ⇒ Object

Returns the sequence name for a table’s primary key or some other specified key.



241
242
243
244
245
246
247
 
# File 'lib/active_record/connection_adapters/redshift/schema_statements.rb', line 241

def default_sequence_name(table_name, pk = nil) #:nodoc:
  result = serial_sequence(table_name, pk || 'id')
  return nil unless result
  Utils.extract_schema_qualified_name(result).to_s
rescue ActiveRecord::StatementInvalid
  Redshift::Name.new(nil, "#{table_name}_#{pk || 'id'}_seq").to_s
end

#drop_database(name) ⇒ Object

Drops a PostgreSQL database.

Example:

drop_database 'matt_development'



83
84
85
 
# File 'lib/active_record/connection_adapters/redshift/schema_statements.rb', line 83

def drop_database(name) #:nodoc:
  execute "DROP DATABASE #{quote_table_name(name)}"
end

#drop_schema(schema_name) ⇒ Object

Drops the schema for the given schema name.



208
209
210
 
# File 'lib/active_record/connection_adapters/redshift/schema_statements.rb', line 208

def drop_schema schema_name
  execute "DROP SCHEMA #{schema_name} CASCADE"
end

#drop_table(table_name, options = {}) ⇒ Object 



113
114
115
 
# File 'lib/active_record/connection_adapters/redshift/schema_statements.rb', line 113

def drop_table(table_name, options = {})
  execute "DROP TABLE #{quote_table_name(table_name)}#{' CASCADE' if options[:force] == :cascade}"
end

#encoding ⇒ Object

Returns the current database encoding format.



170
171
172
173
174
175
 
# File 'lib/active_record/connection_adapters/redshift/schema_statements.rb', line 170

def encoding
  query("    SELECT pg_encoding_to_char(pg_database.encoding) FROM pg_database\n    WHERE pg_database.datname LIKE '\#{current_database}'\n  end_sql\nend\n", 'SCHEMA')[0][0]

#extract_foreign_key_action(specifier) ⇒ Object

:nodoc:



488
489
490
491
492
493
494
 
# File 'lib/active_record/connection_adapters/redshift/schema_statements.rb', line 488

def extract_foreign_key_action(specifier) # :nodoc:
  case specifier
  when 'c'; :cascade
  when 'n'; :nullify
  when 'r'; :restrict
  end
end

#foreign_keys(table_name) ⇒ Object 



459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
 
# File 'lib/active_record/connection_adapters/redshift/schema_statements.rb', line 459

def foreign_keys(table_name)
  fk_info = select_all "    SELECT t2.oid::regclass AS to_table, a1.attname AS column, a2.attname AS primary_key, c.conname AS name, c.confupdtype AS on_update, c.confdeltype AS on_delete\n    FROM pg_constraint c\n    JOIN pg_class t1 ON c.conrelid = t1.oid\n    JOIN pg_class t2 ON c.confrelid = t2.oid\n    JOIN pg_attribute a1 ON a1.attnum = c.conkey[1] AND a1.attrelid = t1.oid\n    JOIN pg_attribute a2 ON a2.attnum = c.confkey[1] AND a2.attrelid = t2.oid\n    JOIN pg_namespace t3 ON c.connamespace = t3.oid\n    WHERE c.contype = 'f'\n      AND t1.relname = \#{quote(table_name)}\n      AND t3.nspname = ANY (current_schemas(false))\n    ORDER BY c.conname\n  SQL\n\n  fk_info.map do |row|\n    options = {\n      column: row['column'],\n      name: row['name'],\n      primary_key: row['primary_key']\n    }\n\n    options[:on_delete] = extract_foreign_key_action(row['on_delete'])\n    options[:on_update] = extract_foreign_key_action(row['on_update'])\n\n    ForeignKeyDefinition.new(table_name, row['to_table'], options)\n  end\nend\n".strip_heredoc

#index_name_exists?(table_name, index_name, default) ⇒ Boolean

Returns:

  • (Boolean) 


126
127
128
129
130
131
132
133
134
135
136
137
 
# File 'lib/active_record/connection_adapters/redshift/schema_statements.rb', line 126

def index_name_exists?(table_name, index_name, default)
  exec_query("    SELECT COUNT(*)\n    FROM pg_class t\n    INNER JOIN pg_index d ON t.oid = d.indrelid\n    INNER JOIN pg_class i ON d.indexrelid = i.oid\n    WHERE i.relkind = 'i'\n      AND i.relname = '\#{index_name}'\n      AND t.relname = '\#{table_name}'\n      AND i.relnamespace IN (SELECT oid FROM pg_namespace WHERE nspname = ANY (current_schemas(false)) )\n  SQL\nend\n", 'SCHEMA').rows.first[0].to_i > 0

#index_name_length ⇒ Object 



496
497
498
 
# File 'lib/active_record/connection_adapters/redshift/schema_statements.rb', line 496

def index_name_length
  63
end

#indexes(table_name, name = nil) ⇒ Object

Returns an array of indexes for the given table.



140
141
142
 
# File 'lib/active_record/connection_adapters/redshift/schema_statements.rb', line 140

def indexes(table_name, name = nil)
  []
end

#new_column(name, default, cast_type, sql_type = nil, null = true, default_function = nil) ⇒ Object

:nodoc:



155
156
157
 
# File 'lib/active_record/connection_adapters/redshift/schema_statements.rb', line 155

def new_column(name, default, cast_type, sql_type = nil, null = true, default_function = nil) # :nodoc:
  RedshiftColumn.new(name, default, cast_type, sql_type, null, default_function)
end

#pk_and_sequence_for(table) ⇒ Object

Returns a table’s primary key and belonging sequence.



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
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
 
# File 'lib/active_record/connection_adapters/redshift/schema_statements.rb', line 296

def pk_and_sequence_for(table) #:nodoc:
  # First try looking for a sequence with a dependency on the
  # given table's primary key.
  result = query("    SELECT attr.attname, nsp.nspname, seq.relname\n    FROM pg_class      seq,\n         pg_attribute  attr,\n         pg_depend     dep,\n         pg_constraint cons,\n         pg_namespace  nsp\n    WHERE seq.oid           = dep.objid\n      AND seq.relkind       = 'S'\n      AND attr.attrelid     = dep.refobjid\n      AND attr.attnum       = dep.refobjsubid\n      AND attr.attrelid     = cons.conrelid\n      AND attr.attnum       = cons.conkey[1]\n      AND seq.relnamespace  = nsp.oid\n      AND cons.contype      = 'p'\n      AND dep.classid       = 'pg_class'::regclass\n      AND dep.refobjid      = '\#{quote_table_name(table)}'::regclass\n  end_sql\n\n  if result.nil? or result.empty?\n    result = query(<<-end_sql, 'SCHEMA')[0]\n      SELECT attr.attname, nsp.nspname,\n        CASE\n          WHEN pg_get_expr(def.adbin, def.adrelid) !~* 'nextval' THEN NULL\n          WHEN split_part(pg_get_expr(def.adbin, def.adrelid), '''', 2) ~ '.' THEN\n            substr(split_part(pg_get_expr(def.adbin, def.adrelid), '''', 2),\n                   strpos(split_part(pg_get_expr(def.adbin, def.adrelid), '''', 2), '.')+1)\n          ELSE split_part(pg_get_expr(def.adbin, def.adrelid), '''', 2)\n        END\n      FROM pg_class       t\n      JOIN pg_attribute   attr ON (t.oid = attrelid)\n      JOIN pg_attrdef     def  ON (adrelid = attrelid AND adnum = attnum)\n      JOIN pg_constraint  cons ON (conrelid = adrelid AND adnum = conkey[1])\n      JOIN pg_namespace   nsp  ON (t.relnamespace = nsp.oid)\n      WHERE t.oid = '\#{quote_table_name(table)}'::regclass\n        AND cons.contype = 'p'\n        AND pg_get_expr(def.adbin, def.adrelid) ~* 'nextval|uuid_generate'\n    end_sql\n  end\n\n  pk = result.shift\n  if result.last\n    [pk, Redshift::Name.new(*result)]\n  else\n    [pk, nil]\n  end\nrescue\n  nil\nend\n", 'SCHEMA')[0]

#primary_key(table) ⇒ Object

Returns just a table’s primary key



350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
 
# File 'lib/active_record/connection_adapters/redshift/schema_statements.rb', line 350

def primary_key(table)
  # Passing the env variable REDSHIFT_SCHEMA will allow the correct generation of id
  # fields that are not of integer/uuid/serial type
  return if ENV['REDSHIFT_SCHEMA']
  pks = exec_query("    SELECT DISTINCT attr.attname\n    FROM pg_attribute attr\n    INNER JOIN pg_depend dep ON attr.attrelid = dep.refobjid AND attr.attnum = dep.refobjsubid\n    INNER JOIN pg_constraint cons ON attr.attrelid = cons.conrelid AND attr.attnum = cons.conkey[1]\n    WHERE cons.contype = 'p'\n      AND dep.refobjid = '\#{quote_table_name(table)}'::regclass\n  end_sql\n\n  return nil unless pks.count == 1\n  pks[0][0]\nend\n", 'SCHEMA').rows

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

Drops the database specified on the name attribute and creates it again using the provided options.



41
42
43
44
 
# File 'lib/active_record/connection_adapters/redshift/schema_statements.rb', line 41

def recreate_database(name, options = {}) #:nodoc:
  drop_database(name)
  create_database(name, options)
end

#remove_index!(table_name, index_name) ⇒ Object

:nodoc:



448
449
450
 
# File 'lib/active_record/connection_adapters/redshift/schema_statements.rb', line 448

def remove_index!(table_name, index_name) #:nodoc:
  # ignore
end

#rename_column(table_name, column_name, new_column_name) ⇒ Object

Renames a column in a table.



438
439
440
441
442
 
# File 'lib/active_record/connection_adapters/redshift/schema_statements.rb', line 438

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

#rename_index(table_name, old_name, new_name) ⇒ Object 



452
453
454
455
456
457
 
# File 'lib/active_record/connection_adapters/redshift/schema_statements.rb', line 452

def rename_index(table_name, old_name, new_name)
  validate_index_length!(table_name, new_name)

  execute "ALTER INDEX #{quote_column_name(old_name)} RENAME TO #{quote_table_name(new_name)}"
  # ignore
end

#rename_table(table_name, new_name) ⇒ Object

Renames a table. Also renames a table’s primary key sequence if the sequence name exists and matches the Active Record default.

Example:

rename_table('octopuses', 'octopi')



373
374
375
376
377
378
379
380
381
382
383
384
385
386
 
# File 'lib/active_record/connection_adapters/redshift/schema_statements.rb', line 373

def rename_table(table_name, new_name)
  clear_cache!
  execute "ALTER TABLE #{quote_table_name(table_name)} RENAME TO #{quote_table_name(new_name)}"
  pk, seq = pk_and_sequence_for(new_name)
  if seq && seq.identifier == "#{table_name}_#{pk}_seq"
    new_seq = "#{new_name}_#{pk}_seq"
    idx = "#{table_name}_pkey"
    new_idx = "#{new_name}_pkey"
    execute "ALTER TABLE #{quote_table_name(seq)} RENAME TO #{quote_table_name(new_seq)}"
    execute "ALTER INDEX #{quote_table_name(idx)} RENAME TO #{quote_table_name(new_idx)}"
  end

  rename_table_indexes(table_name, new_name)
end

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

Resets the sequence of a table’s primary key to the maximum value.



274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
 
# File 'lib/active_record/connection_adapters/redshift/schema_statements.rb', line 274

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 @logger && pk && !sequence
    @logger.warn "#{table} has primary key #{pk} with no default sequence"
  end

  if pk && sequence
    quoted_sequence = quote_table_name(sequence)

    select_value "      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)\n    end_sql\n  end\nend\n", 'SCHEMA'

#schema_exists?(name) ⇒ Boolean

Returns true if schema exists.

Returns:

  • (Boolean) 


118
119
120
121
122
123
124
 
# File 'lib/active_record/connection_adapters/redshift/schema_statements.rb', line 118

def schema_exists?(name)
  exec_query("    SELECT COUNT(*)\n    FROM pg_namespace\n    WHERE nspname = '\#{name}'\n  SQL\nend\n", 'SCHEMA').rows.first[0].to_i > 0

#schema_names ⇒ Object

Returns an array of schema names.



192
193
194
195
196
197
198
199
200
 
# File 'lib/active_record/connection_adapters/redshift/schema_statements.rb', line 192

def schema_names
  query("    SELECT nspname\n      FROM pg_namespace\n     WHERE nspname !~ '^pg_.*'\n       AND nspname NOT IN ('information_schema')\n     ORDER by nspname;\n  SQL\nend\n", 'SCHEMA').flatten

#schema_search_path ⇒ Object

Returns the active schema search path.



225
226
227
 
# File 'lib/active_record/connection_adapters/redshift/schema_statements.rb', line 225

def schema_search_path
  @schema_search_path ||= query('SHOW search_path', 'SCHEMA')[0][0]
end

#schema_search_path=(schema_csv) ⇒ Object

Sets the schema search path to a string of comma-separated schema names. Names beginning with $ have to be quoted (e.g. $user => ‘$user’). See: www.postgresql.org/docs/current/static/ddl-schemas.html

This should be not be called manually but set in database.yml.



217
218
219
220
221
222
 
# File 'lib/active_record/connection_adapters/redshift/schema_statements.rb', line 217

def schema_search_path=(schema_csv)
  if schema_csv
    execute("SET search_path TO #{schema_csv}", 'SCHEMA')
    @schema_search_path = schema_csv
  end
end

#serial_sequence(table, column) ⇒ Object 



249
250
251
252
253
254
 
# File 'lib/active_record/connection_adapters/redshift/schema_statements.rb', line 249

def serial_sequence(table, column)
  result = exec_query("    SELECT pg_get_serial_sequence('\#{table}', '\#{column}')\n  eosql\n  result.rows.first.first\nend\n", 'SCHEMA')

#set_pk_sequence!(table, value) ⇒ Object

Sets the sequence of a table’s primary key to the specified value.



257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
 
# File 'lib/active_record/connection_adapters/redshift/schema_statements.rb', line 257

def set_pk_sequence!(table, value) #:nodoc:
  pk, sequence = pk_and_sequence_for(table)

  if pk
    if sequence
      quoted_sequence = quote_table_name(sequence)

      select_value "      SELECT setval('\#{quoted_sequence}', \#{value})\n      end_sql\n    else\n      @logger.warn \"\#{table} has primary key \#{pk} with no default sequence\" if @logger\n    end\n  end\nend\n", 'SCHEMA'

#table_exists?(name) ⇒ Boolean

Returns true if table exists. If the schema is not specified as part of name then it will only find tables within the current schema search path (regardless of permissions to access tables in other schemas)

Returns:

  • (Boolean) 


99
100
101
102
103
104
105
106
107
108
109
110
111
 
# File 'lib/active_record/connection_adapters/redshift/schema_statements.rb', line 99

def table_exists?(name)
  name = Utils.extract_schema_qualified_name(name.to_s)
  return false unless name.identifier

  exec_query("      SELECT COUNT(*)\n      FROM pg_class c\n      LEFT JOIN pg_namespace n ON n.oid = c.relnamespace\n      WHERE c.relkind IN ('r','v','m') -- (r)elation/table, (v)iew, (m)aterialized view\n      AND c.relname = '\#{name.identifier}'\n      AND n.nspname = \#{name.schema ? \"'\#{name.schema}'\" : 'ANY (current_schemas(false))'}\n  SQL\nend\n", 'SCHEMA').rows.first[0].to_i > 0

#tables(name = nil) ⇒ Object

Returns the list of all tables in the schema search path or a specified schema.



88
89
90
91
92
93
94
 
# File 'lib/active_record/connection_adapters/redshift/schema_statements.rb', line 88

def tables(name = nil)
  query("    SELECT tablename\n    FROM pg_tables\n    WHERE schemaname = ANY (current_schemas(false))\n  SQL\nend\n", 'SCHEMA').map { |row| "#{row[0]}.#{row[1]}" }

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

Maps logical Rails types to PostgreSQL-specific data types.



501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
 
# File 'lib/active_record/connection_adapters/redshift/schema_statements.rb', line 501

def type_to_sql(type, limit = nil, precision = nil, scale = nil)
  case type.to_s
  when 'boolean'
    super(type)
  when 'binary'
    # PostgreSQL doesn't support limits on binary (bytea) columns.
    # The hard limit is 1Gb, because of a 32-bit size field, and TOAST.
    case limit
    when nil, 0..0x3fffffff; super(type)
    else raise(ActiveRecordError, "No binary type has byte size #{limit}.")
    end
  when 'text'
    # PostgreSQL doesn't support limits on text columns.
    # The hard limit is 1Gb, according to section 8.3 in the manual.
    case limit
    when nil, 0..0x3fffffff; super(type)
    else raise(ActiveRecordError, "The limit on text can be at most 1GB - 1byte.")
    end
  when 'integer'
    return 'integer' unless limit

    case limit
      when 1, 2; 'smallint'
      when 3, 4; 'integer'
      when 5..8; 'bigint'
      else raise(ActiveRecordError, "No integer type has byte size #{limit}. Use a numeric with precision 0 instead.")
    end
  when 'datetime'
    return super unless precision

    case precision
      when 0..6; "timestamp(#{precision})"
      else raise(ActiveRecordError, "No timestamp type has precision of #{precision}. The allowed range of precision is from 0 to 6")
    end
  else
    super
  end
end