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 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
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

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 411
411:       def calc_found_rows
412:         clone(:calc_found_rows => true)
413:       end

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

[Source]

     # File lib/sequel/adapters/shared/mysql.rb, line 367
367:       def complex_expression_sql_append(sql, op, args)
368:         case op
369:         when :IN, "NOT IN""NOT IN"
370:           ds = args.at(1)
371:           if ds.is_a?(Sequel::Dataset) && ds.opts[:limit]
372:             super(sql, op, [args.at(0), ds.from_self])
373:           else
374:             super
375:           end
376:         when :~, '!~''!~', '~*''~*', '!~*''!~*', :LIKE, 'NOT LIKE''NOT LIKE', :ILIKE, 'NOT ILIKE''NOT ILIKE'
377:           sql << PAREN_OPEN
378:           literal_append(sql, args.at(0))
379:           sql << SPACE
380:           sql << 'NOT ' if ['NOT LIKE''NOT LIKE', 'NOT ILIKE''NOT ILIKE', '!~''!~', '!~*''!~*'].include?(op)
381:           sql << ([:~, '!~''!~', '~*''~*', '!~*''!~*'].include?(op) ? REGEXP : LIKE)
382:           sql << SPACE
383:           sql << BINARY if [:~, '!~''!~', :LIKE, 'NOT LIKE''NOT LIKE'].include?(op)
384:           literal_append(sql, args.at(1))
385:           sql << PAREN_CLOSE
386:         when '||''||'
387:           if args.length > 1
388:             sql << CONCAT
389:             array_sql_append(sql, args)
390:           else
391:             literal_append(sql, args.at(0))
392:           end
393:         when 'B~''B~'
394:           sql << CAST_BITCOMP_OPEN
395:           literal_append(sql, args.at(0))
396:           sql << CAST_BITCOMP_CLOSE
397:         else
398:           super
399:         end
400:       end

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

[Source]

     # File lib/sequel/adapters/shared/mysql.rb, line 403
403:       def distinct(*args)
404:         args.empty? ? super : group(*args)
405:       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 416
416:       def for_share
417:         lock_style(:share)
418:       end

Adds full text filter

[Source]

     # File lib/sequel/adapters/shared/mysql.rb, line 421
421:       def full_text_search(cols, terms, opts = {})
422:         filter(full_text_sql(cols, terms, opts))
423:       end

MySQL specific full text search syntax.

[Source]

     # File lib/sequel/adapters/shared/mysql.rb, line 426
426:       def full_text_sql(cols, term, opts = {})
427:         "MATCH #{literal(Array(cols))} AGAINST (#{literal(Array(term).join(' '))}#{" IN BOOLEAN MODE" if opts[:boolean]})"
428:       end

MySQL allows HAVING clause on ungrouped datasets.

[Source]

     # File lib/sequel/adapters/shared/mysql.rb, line 431
431:       def having(*cond, &block)
432:         _filter(:having, *cond, &block)
433:       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 464
464:       def insert_ignore
465:         clone(:insert_ignore=>true)
466:       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 437
437:       def join_table(type, table, expr=nil, table_alias={}, &block)
438:         type = :inner if (type == :cross) && !expr.nil?
439:         raise(Sequel::Error, "MySQL doesn't support FULL OUTER JOIN") if type == :full_outer
440:         super(type, table, expr, table_alias, &block)
441:       end

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

[Source]

     # File lib/sequel/adapters/shared/mysql.rb, line 445
445:       def join_type_sql(join_type)
446:         case join_type
447:         when :straight
448:           STRAIGHT_JOIN
449:         when :natural_inner
450:           NATURAL_LEFT_JOIN
451:         else
452:           super
453:         end
454:       end

MySQL specific syntax for inserting multiple values at once.

[Source]

     # File lib/sequel/adapters/shared/mysql.rb, line 492
492:       def multi_insert_sql(columns, values)
493:         sql = LiteralString.new('VALUES ')
494:         expression_list_append(sql, values.map{|r| Array(r)})
495:         [insert_sql(columns, sql)]
496:       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 487
487:       def on_duplicate_key_update(*args)
488:         clone(:on_duplicate_key_update => args)
489:       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 500
500:       def provides_accurate_rows_matched?
501:         false
502:       end

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

[Source]

     # File lib/sequel/adapters/shared/mysql.rb, line 505
505:       def quoted_identifier_append(sql, c)
506:         sql << BACKTICK << c.to_s << BACKTICK
507:       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 511
511:       def replace_sql(*values)
512:         clone(:replace=>true).insert_sql(*values)
513:       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 517
517:       def supports_distinct_on?
518:         true
519:       end

MySQL does not support INTERSECT or EXCEPT

[Source]

     # File lib/sequel/adapters/shared/mysql.rb, line 522
522:       def supports_intersect_except?
523:         false
524:       end

MySQL supports modifying joined datasets

[Source]

     # File lib/sequel/adapters/shared/mysql.rb, line 527
527:       def supports_modifying_joins?
528:         true
529:       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 533
533:       def supports_ordered_distinct_on?
534:         false
535:       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 540
540:       def supports_timestamp_usecs?
541:         false
542:       end

[Validate]