Module Sequel::MySQL::DatasetMethods
In: lib/sequel/adapters/shared/mysql.rb

Dataset methods shared by datasets that use MySQL databases.

Methods

Constants

BOOL_TRUE = '1'.freeze
BOOL_FALSE = '0'.freeze
COMMA_SEPARATOR = ', '.freeze
FOR_SHARE = ' LOCK IN SHARE MODE'.freeze
SQL_CALC_FOUND_ROWS = ' SQL_CALC_FOUND_ROWS'.freeze
DELETE_CLAUSE_METHODS = Dataset.clause_methods(:delete, %w'delete from where order limit')
INSERT_CLAUSE_METHODS = Dataset.clause_methods(:insert, %w'insert ignore into columns values on_duplicate_key_update')
SELECT_CLAUSE_METHODS = Dataset.clause_methods(:select, %w'select distinct calc_found_rows columns from join where group having compounds order limit lock')
UPDATE_CLAUSE_METHODS = Dataset.clause_methods(:update, %w'update ignore table set where order limit')
SPACE = Dataset::SPACE
PAREN_OPEN = Dataset::PAREN_OPEN
PAREN_CLOSE = Dataset::PAREN_CLOSE
NOT_SPACE = Dataset::NOT_SPACE
FROM = Dataset::FROM
INSERT = Dataset::INSERT
COMMA = Dataset::COMMA
LIMIT = Dataset::LIMIT
GROUP_BY = Dataset::GROUP_BY
REGEXP = 'REGEXP'.freeze
LIKE = 'LIKE'.freeze
BINARY = 'BINARY '.freeze
CONCAT = "CONCAT".freeze
CAST_BITCOMP_OPEN = "CAST(~".freeze
CAST_BITCOMP_CLOSE = " AS SIGNED INTEGER)".freeze
STRAIGHT_JOIN = 'STRAIGHT_JOIN'.freeze
NATURAL_LEFT_JOIN = 'NATURAL LEFT JOIN'.freeze
BACKTICK = '`'.freeze
EMPTY_COLUMNS = " ()".freeze
EMPTY_VALUES = " VALUES ()".freeze
IGNORE = " IGNORE".freeze
REPLACE = 'REPLACE'.freeze
ON_DUPLICATE_KEY_UPDATE = " ON DUPLICATE KEY UPDATE ".freeze
EQ_VALUES = '=VALUES('.freeze
EQ = '='.freeze
WITH_ROLLUP = ' WITH ROLLUP'.freeze

Public Instance methods

Sets up the select methods to use SQL_CALC_FOUND_ROWS option.

  dataset.calc_found_rows.limit(10)
  # SELECT SQL_CALC_FOUND_ROWS * FROM table LIMIT 10

[Source]

     # File lib/sequel/adapters/shared/mysql.rb, line 418
418:       def calc_found_rows
419:         clone(:calc_found_rows => true)
420:       end

MySQL specific syntax for LIKE/REGEXP searches, as well as string concatenation.

[Source]

     # File lib/sequel/adapters/shared/mysql.rb, line 374
374:       def complex_expression_sql_append(sql, op, args)
375:         case op
376:         when :IN, "NOT IN""NOT IN"
377:           ds = args.at(1)
378:           if ds.is_a?(Sequel::Dataset) && ds.opts[:limit]
379:             super(sql, op, [args.at(0), ds.from_self])
380:           else
381:             super
382:           end
383:         when :~, '!~''!~', '~*''~*', '!~*''!~*', :LIKE, 'NOT LIKE''NOT LIKE', :ILIKE, 'NOT ILIKE''NOT ILIKE'
384:           sql << PAREN_OPEN
385:           literal_append(sql, args.at(0))
386:           sql << SPACE
387:           sql << 'NOT ' if ['NOT LIKE''NOT LIKE', 'NOT ILIKE''NOT ILIKE', '!~''!~', '!~*''!~*'].include?(op)
388:           sql << ([:~, '!~''!~', '~*''~*', '!~*''!~*'].include?(op) ? REGEXP : LIKE)
389:           sql << SPACE
390:           sql << BINARY if [:~, '!~''!~', :LIKE, 'NOT LIKE''NOT LIKE'].include?(op)
391:           literal_append(sql, args.at(1))
392:           sql << PAREN_CLOSE
393:         when '||''||'
394:           if args.length > 1
395:             sql << CONCAT
396:             array_sql_append(sql, args)
397:           else
398:             literal_append(sql, args.at(0))
399:           end
400:         when 'B~''B~'
401:           sql << CAST_BITCOMP_OPEN
402:           literal_append(sql, args.at(0))
403:           sql << CAST_BITCOMP_CLOSE
404:         else
405:           super
406:         end
407:       end

Use GROUP BY instead of DISTINCT ON if arguments are provided.

[Source]

     # File lib/sequel/adapters/shared/mysql.rb, line 410
410:       def distinct(*args)
411:         args.empty? ? super : group(*args)
412:       end

Return a cloned dataset which will use LOCK IN SHARE MODE to lock returned rows.

[Source]

     # File lib/sequel/adapters/shared/mysql.rb, line 423
423:       def for_share
424:         lock_style(:share)
425:       end

Adds full text filter

[Source]

     # File lib/sequel/adapters/shared/mysql.rb, line 428
428:       def full_text_search(cols, terms, opts = {})
429:         filter(full_text_sql(cols, terms, opts))
430:       end

MySQL specific full text search syntax.

[Source]

     # File lib/sequel/adapters/shared/mysql.rb, line 433
433:       def full_text_sql(cols, terms, opts = {})
434:         terms = terms.join(' ') if terms.is_a?(Array)
435:         SQL::PlaceholderLiteralString.new("MATCH ? AGAINST (?#{" IN BOOLEAN MODE" if opts[:boolean]})", [Array(cols), terms], true)
436:       end

MySQL allows HAVING clause on ungrouped datasets.

[Source]

     # File lib/sequel/adapters/shared/mysql.rb, line 439
439:       def having(*cond, &block)
440:         _filter(:having, *cond, &block)
441:       end

Sets up the insert methods to use INSERT IGNORE. Useful if you have a unique key and want to just skip inserting rows that violate the unique key restriction.

  dataset.insert_ignore.multi_insert(
   [{:name => 'a', :value => 1}, {:name => 'b', :value => 2}]
  )
  # INSERT IGNORE INTO tablename (name, value) VALUES (a, 1), (b, 2)

[Source]

     # File lib/sequel/adapters/shared/mysql.rb, line 472
472:       def insert_ignore
473:         clone(:insert_ignore=>true)
474:       end

Transforms an CROSS JOIN to an INNER JOIN if the expr is not nil. Raises an error on use of :full_outer type, since MySQL doesn‘t support it.

[Source]

     # File lib/sequel/adapters/shared/mysql.rb, line 445
445:       def join_table(type, table, expr=nil, table_alias={}, &block)
446:         type = :inner if (type == :cross) && !expr.nil?
447:         raise(Sequel::Error, "MySQL doesn't support FULL OUTER JOIN") if type == :full_outer
448:         super(type, table, expr, table_alias, &block)
449:       end

Transforms :natural_inner to NATURAL LEFT JOIN and straight to STRAIGHT_JOIN.

[Source]

     # File lib/sequel/adapters/shared/mysql.rb, line 453
453:       def join_type_sql(join_type)
454:         case join_type
455:         when :straight
456:           STRAIGHT_JOIN
457:         when :natural_inner
458:           NATURAL_LEFT_JOIN
459:         else
460:           super
461:         end
462:       end

MySQL specific syntax for inserting multiple values at once.

[Source]

     # File lib/sequel/adapters/shared/mysql.rb, line 500
500:       def multi_insert_sql(columns, values)
501:         sql = LiteralString.new('VALUES ')
502:         expression_list_append(sql, values.map{|r| Array(r)})
503:         [insert_sql(columns, sql)]
504:       end

Sets up the insert methods to use ON DUPLICATE KEY UPDATE If you pass no arguments, ALL fields will be updated with the new values. If you pass the fields you want then ONLY those field will be updated.

Useful if you have a unique key and want to update inserting rows that violate the unique key restriction.

  dataset.on_duplicate_key_update.multi_insert(
   [{:name => 'a', :value => 1}, {:name => 'b', :value => 2}]
  )
  # INSERT INTO tablename (name, value) VALUES (a, 1), (b, 2)
  # ON DUPLICATE KEY UPDATE name=VALUES(name), value=VALUES(value)

  dataset.on_duplicate_key_update(:value).multi_insert(
    [{:name => 'a', :value => 1}, {:name => 'b', :value => 2}]
  )
  # INSERT INTO tablename (name, value) VALUES (a, 1), (b, 2)
  # ON DUPLICATE KEY UPDATE value=VALUES(value)

[Source]

     # File lib/sequel/adapters/shared/mysql.rb, line 495
495:       def on_duplicate_key_update(*args)
496:         clone(:on_duplicate_key_update => args)
497:       end

MySQL uses the number of rows actually modified in the update, instead of the number of matched by the filter.

[Source]

     # File lib/sequel/adapters/shared/mysql.rb, line 508
508:       def provides_accurate_rows_matched?
509:         false
510:       end

MySQL uses the nonstandard ` (backtick) for quoting identifiers.

[Source]

     # File lib/sequel/adapters/shared/mysql.rb, line 513
513:       def quoted_identifier_append(sql, c)
514:         sql << BACKTICK << c.to_s << BACKTICK
515:       end

MySQL specific syntax for REPLACE (aka UPSERT, or update if exists, insert if it doesn‘t).

[Source]

     # File lib/sequel/adapters/shared/mysql.rb, line 519
519:       def replace_sql(*values)
520:         clone(:replace=>true).insert_sql(*values)
521:       end

MySQL can emulate DISTINCT ON with its non-standard GROUP BY implementation, though the rows returned cannot be made deterministic through ordering.

[Source]

     # File lib/sequel/adapters/shared/mysql.rb, line 525
525:       def supports_distinct_on?
526:         true
527:       end

MySQL supports GROUP BY WITH ROLLUP (but not CUBE)

[Source]

     # File lib/sequel/adapters/shared/mysql.rb, line 530
530:       def supports_group_rollup?
531:         true
532:       end

MySQL does not support INTERSECT or EXCEPT

[Source]

     # File lib/sequel/adapters/shared/mysql.rb, line 535
535:       def supports_intersect_except?
536:         false
537:       end

MySQL supports modifying joined datasets

[Source]

     # File lib/sequel/adapters/shared/mysql.rb, line 540
540:       def supports_modifying_joins?
541:         true
542:       end

MySQL‘s DISTINCT ON emulation using GROUP BY does not respect the queries ORDER BY clause.

[Source]

     # File lib/sequel/adapters/shared/mysql.rb, line 546
546:       def supports_ordered_distinct_on?
547:         false
548:       end

MySQL does support fractional timestamps in literal timestamps, but it ignores them. Also, using them seems to cause problems on 1.9. Since they are ignored anyway, not using them is probably best.

[Source]

     # File lib/sequel/adapters/shared/mysql.rb, line 553
553:       def supports_timestamp_usecs?
554:         false
555:       end

Sets up the update methods to use UPDATE IGNORE. Useful if you have a unique key and want to just skip updating rows that violate the unique key restriction.

  dataset.update_ignore.update({:name => 'a', :value => 1})
  # UPDATE IGNORE tablename SET name = 'a', value = 1

[Source]

     # File lib/sequel/adapters/shared/mysql.rb, line 563
563:       def update_ignore
564:         clone(:update_ignore=>true)
565:       end

[Validate]