Module: Sequel::Oracle::DatasetMethods

Included in:
JDBC::Oracle::Dataset, Dataset
Defined in:
lib/sequel/adapters/shared/oracle.rb

Constant Summary collapse

ROW_NUMBER_EXPRESSION = 
LiteralString.new('ROWNUM').freeze
BITAND_PROC = 
lambda{|a, b| Sequel.lit(["CAST(BITAND(", ", ", ") AS INTEGER)"], a, b)}

Instance Method Summary collapse

Instance Method Details

#complex_expression_sql_append(sql, op, args) ⇒ Object 



336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
 
# File 'lib/sequel/adapters/shared/oracle.rb', line 336

def complex_expression_sql_append(sql, op, args)
  case op
  when :&
    complex_expression_arg_pairs_append(sql, args, &BITAND_PROC)
  when :|
    complex_expression_arg_pairs_append(sql, args){|a, b| Sequel.lit(["(", " - ", " + ", ")"], a, complex_expression_arg_pairs([a, b], &BITAND_PROC), b)}
  when :^
    complex_expression_arg_pairs_append(sql, args) do |*x|
      s1 = complex_expression_arg_pairs(x){|a, b| Sequel.lit(["(", " - ", " + ", ")"], a, complex_expression_arg_pairs([a, b], &BITAND_PROC), b)}
      s2 = complex_expression_arg_pairs(x, &BITAND_PROC)
      Sequel.lit(["(", " - ", ")"], s1, s2)
    end
  when :~, :'!~', :'~*', :'!~*'
    raise InvalidOperation, "Pattern matching via regular expressions is not supported in this Oracle version" unless supports_regexp?
    if op == :'!~' || op == :'!~*'
      sql << 'NOT '
    end
    sql << 'REGEXP_LIKE('
    literal_append(sql, args[0])
    sql << ','
    literal_append(sql, args[1])
    if op == :'~*' || op == :'!~*'
      sql << ", 'i'"
    end
    sql << ')'
  when :%, :<<, :>>, :'B~'
    complex_expression_emulate_append(sql, op, args)
  else
    super
  end
end

#constant_sql_append(sql, c) ⇒ Object

Oracle doesn’t support CURRENT_TIME, as it doesn’t have a type for storing just time values without a date, so use CURRENT_TIMESTAMP in its place.



371
372
373
374
375
376
377
 
# File 'lib/sequel/adapters/shared/oracle.rb', line 371

def constant_sql_append(sql, c)
  if c == :CURRENT_TIME
    super(sql, :CURRENT_TIMESTAMP)
  else
    super
  end
end

#empty? ⇒ Boolean

Use a custom expression with EXISTS to determine whether a dataset is empty.

Returns:

  • (Boolean) 


387
388
389
390
391
392
393
394
 
# File 'lib/sequel/adapters/shared/oracle.rb', line 387

def empty?
  if @opts[:sql]
    naked.each{return false}
    true
  else
    db[:dual].where(@opts[:offset] ? exists : unordered.exists).get(1) == nil
  end
end

#except(dataset, opts = OPTS) ⇒ Object

Oracle uses MINUS instead of EXCEPT, and doesn’t support EXCEPT ALL

Raises:



380
381
382
383
 
# File 'lib/sequel/adapters/shared/oracle.rb', line 380

def except(dataset, opts=OPTS)
  raise(Sequel::Error, "EXCEPT ALL not supported") if opts[:all]
  compound_clone(:minus, dataset, opts)
end

#recursive_cte_requires_column_aliases? ⇒ Boolean

Oracle requires recursive CTEs to have column aliases.

Returns:

  • (Boolean) 


444
445
446
 
# File 'lib/sequel/adapters/shared/oracle.rb', line 444

def recursive_cte_requires_column_aliases?
  true
end

#requires_sql_standard_datetimes? ⇒ Boolean

Oracle requires SQL standard datetimes

Returns:

  • (Boolean) 


397
398
399
 
# File 'lib/sequel/adapters/shared/oracle.rb', line 397

def requires_sql_standard_datetimes?
  true
end

#select_sql ⇒ Object

Handle LIMIT by using a unlimited subselect filtered with ROWNUM, unless Oracle 12 is used.



410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
 
# File 'lib/sequel/adapters/shared/oracle.rb', line 410

def select_sql
  return super if @opts[:sql]
  return super if supports_fetch_next_rows?

  o = @opts[:offset]
  if o && o != 0
    columns = clone(:append_sql=>String.new, :placeholder_literal_null=>true).columns
    dsa1 = dataset_alias(1)
    rn = row_number_column
    limit = @opts[:limit]
    ds = unlimited.
      from_self(:alias=>dsa1).
      select_append(ROW_NUMBER_EXPRESSION.as(rn)).
      from_self(:alias=>dsa1).
      select(*columns).
      where(SQL::Identifier.new(rn) > o)
    ds = ds.where(SQL::Identifier.new(rn) <= Sequel.+(o, limit)) if limit
    sql = @opts[:append_sql] || String.new
    subselect_sql_append(sql, ds)
    sql
  elsif limit = @opts[:limit]
    ds = unlimited
    # Lock doesn't work in subselects, so don't use a subselect when locking.
    # Don't use a subselect if custom SQL is used, as it breaks somethings.
    ds = ds.from_self unless @opts[:lock]
    sql = @opts[:append_sql] || String.new
    subselect_sql_append(sql, ds.where(SQL::ComplexExpression.new(:<=, ROW_NUMBER_EXPRESSION, limit)))
    sql
  else
    super
  end
end

#sequence(s) ⇒ Object

Create a copy of this dataset associated to the given sequence name, which will be used when calling insert to find the most recently inserted value for the sequence.



404
405
406
 
# File 'lib/sequel/adapters/shared/oracle.rb', line 404

def sequence(s)
  clone(:sequence=>s)
end

#server_version ⇒ Object

The version of the database server



534
535
536
 
# File 'lib/sequel/adapters/shared/oracle.rb', line 534

def server_version
  db.server_version(@opts[:server])
end

#supports_cte?(type = :select) ⇒ Boolean

Returns:

  • (Boolean) 


448
449
450
 
# File 'lib/sequel/adapters/shared/oracle.rb', line 448

def supports_cte?(type=:select)
  type == :select
end

#supports_derived_column_lists? ⇒ Boolean

Oracle does not support derived column lists

Returns:

  • (Boolean) 


453
454
455
 
# File 'lib/sequel/adapters/shared/oracle.rb', line 453

def supports_derived_column_lists?
  false
end

#supports_fetch_next_rows? ⇒ Boolean

Oracle supports FETCH NEXT ROWS since 12c, but it doesn’t work when locking or when skipping locked rows.

Returns:

  • (Boolean) 


459
460
461
 
# File 'lib/sequel/adapters/shared/oracle.rb', line 459

def supports_fetch_next_rows?
  server_version >= 12000000 && !(@opts[:lock] || @opts[:skip_locked])
end

#supports_group_cube? ⇒ Boolean

Oracle supports GROUP BY CUBE

Returns:

  • (Boolean) 


464
465
466
 
# File 'lib/sequel/adapters/shared/oracle.rb', line 464

def supports_group_cube?
  true
end

#supports_group_rollup? ⇒ Boolean

Oracle supports GROUP BY ROLLUP

Returns:

  • (Boolean) 


469
470
471
 
# File 'lib/sequel/adapters/shared/oracle.rb', line 469

def supports_group_rollup?
  true
end

#supports_grouping_sets? ⇒ Boolean

Oracle supports GROUPING SETS

Returns:

  • (Boolean) 


474
475
476
 
# File 'lib/sequel/adapters/shared/oracle.rb', line 474

def supports_grouping_sets?
  true
end

#supports_intersect_except_all? ⇒ Boolean

Oracle does not support INTERSECT ALL or EXCEPT ALL

Returns:

  • (Boolean) 


479
480
481
 
# File 'lib/sequel/adapters/shared/oracle.rb', line 479

def supports_intersect_except_all?
  false
end

#supports_is_true? ⇒ Boolean

Oracle does not support IS TRUE.

Returns:

  • (Boolean) 


484
485
486
 
# File 'lib/sequel/adapters/shared/oracle.rb', line 484

def supports_is_true?
  false
end

#supports_limits_in_correlated_subqueries? ⇒ Boolean

Oracle does not support limits in correlated subqueries.

Returns:

  • (Boolean) 


489
490
491
 
# File 'lib/sequel/adapters/shared/oracle.rb', line 489

def supports_limits_in_correlated_subqueries?
  false
end

#supports_merge? ⇒ Boolean

Oracle supports MERGE

Returns:

  • (Boolean) 


494
495
496
 
# File 'lib/sequel/adapters/shared/oracle.rb', line 494

def supports_merge?
  true
end

#supports_nowait? ⇒ Boolean

Oracle supports NOWAIT.

Returns:

  • (Boolean) 


499
500
501
 
# File 'lib/sequel/adapters/shared/oracle.rb', line 499

def supports_nowait?
  true
end

#supports_offsets_in_correlated_subqueries? ⇒ Boolean

Oracle does not support offsets in correlated subqueries.

Returns:

  • (Boolean) 


504
505
506
 
# File 'lib/sequel/adapters/shared/oracle.rb', line 504

def supports_offsets_in_correlated_subqueries?
  false
end

#supports_regexp? ⇒ Boolean

Oracle 10+ supports pattern matching via regular expressions

Returns:

  • (Boolean) 


539
540
541
 
# File 'lib/sequel/adapters/shared/oracle.rb', line 539

def supports_regexp?
  server_version >= 10010002
end

#supports_select_all_and_column? ⇒ Boolean

Oracle does not support SELECT *, column

Returns:

  • (Boolean) 


509
510
511
 
# File 'lib/sequel/adapters/shared/oracle.rb', line 509

def supports_select_all_and_column?
  false
end

#supports_skip_locked? ⇒ Boolean

Oracle supports SKIP LOCKED.

Returns:

  • (Boolean) 


514
515
516
 
# File 'lib/sequel/adapters/shared/oracle.rb', line 514

def supports_skip_locked?
  true
end

#supports_timestamp_timezones? ⇒ Boolean

Oracle supports timezones in literal timestamps.

Returns:

  • (Boolean) 


519
520
521
 
# File 'lib/sequel/adapters/shared/oracle.rb', line 519

def supports_timestamp_timezones?
  true
end

#supports_where_true? ⇒ Boolean

Oracle does not support WHERE ‘Y’ for WHERE TRUE.

Returns:

  • (Boolean) 


524
525
526
 
# File 'lib/sequel/adapters/shared/oracle.rb', line 524

def supports_where_true?
  false
end

#supports_window_functions? ⇒ Boolean

Oracle supports window functions

Returns:

  • (Boolean) 


529
530
531
 
# File 'lib/sequel/adapters/shared/oracle.rb', line 529

def supports_window_functions?
  true
end