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

Dataset methods shared by datasets that use MySQL databases.

Methods

Included Modules

Sequel::Dataset::Replace

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')
APOS = Dataset::APOS
APOS_RE = Dataset::APOS_RE
DOUBLE_APOS = Dataset::DOUBLE_APOS
SPACE = Dataset::SPACE
PAREN_OPEN = Dataset::PAREN_OPEN
PAREN_CLOSE = Dataset::PAREN_CLOSE
NOT_SPACE = Dataset::NOT_SPACE
FROM = Dataset::FROM
COMMA = Dataset::COMMA
LIMIT = Dataset::LIMIT
GROUP_BY = Dataset::GROUP_BY
ESCAPE = Dataset::ESCAPE
BACKSLASH = Dataset::BACKSLASH
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
BACKTICK_RE = /`/.freeze
DOUBLE_BACKTICK = '``'.freeze
EMPTY_COLUMNS = " ()".freeze
EMPTY_VALUES = " VALUES ()".freeze
IGNORE = " IGNORE".freeze
ON_DUPLICATE_KEY_UPDATE = " ON DUPLICATE KEY UPDATE ".freeze
EQ_VALUES = '=VALUES('.freeze
EQ = '='.freeze
WITH_ROLLUP = ' WITH ROLLUP'.freeze
MATCH_AGAINST = ["(MATCH ".freeze, " AGAINST (".freeze, "))".freeze].freeze
MATCH_AGAINST_BOOLEAN = ["(MATCH ".freeze, " AGAINST (".freeze, " IN BOOLEAN MODE))".freeze].freeze
EXPLAIN = 'EXPLAIN '.freeze
EXPLAIN_EXTENDED = 'EXPLAIN EXTENDED '.freeze
BACKSLASH_RE = /\\/.freeze
QUAD_BACKSLASH = "\\\\\\\\".freeze
BLOB_START = "0x".freeze
HSTAR = "H*".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 620
620:       def calc_found_rows
621:         clone(:calc_found_rows => true)
622:       end

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

[Source]

     # File lib/sequel/adapters/shared/mysql.rb, line 572
572:       def complex_expression_sql_append(sql, op, args)
573:         case op
574:         when :IN, "NOT IN""NOT IN"
575:           ds = args.at(1)
576:           if ds.is_a?(Sequel::Dataset) && ds.opts[:limit]
577:             super(sql, op, [args.at(0), ds.from_self])
578:           else
579:             super
580:           end
581:         when :~, '!~''!~', '~*''~*', '!~*''!~*', :LIKE, 'NOT LIKE''NOT LIKE', :ILIKE, 'NOT ILIKE''NOT ILIKE'
582:           sql << PAREN_OPEN
583:           literal_append(sql, args.at(0))
584:           sql << SPACE
585:           sql << 'NOT ' if ['NOT LIKE''NOT LIKE', 'NOT ILIKE''NOT ILIKE', '!~''!~', '!~*''!~*'].include?(op)
586:           sql << ([:~, '!~''!~', '~*''~*', '!~*''!~*'].include?(op) ? REGEXP : LIKE)
587:           sql << SPACE
588:           sql << BINARY if [:~, '!~''!~', :LIKE, 'NOT LIKE''NOT LIKE'].include?(op)
589:           literal_append(sql, args.at(1))
590:           if [:LIKE, 'NOT LIKE''NOT LIKE', :ILIKE, 'NOT ILIKE''NOT ILIKE'].include?(op)
591:             sql << ESCAPE
592:             literal_append(sql, BACKSLASH)
593:           end
594:           sql << PAREN_CLOSE
595:         when '||''||'
596:           if args.length > 1
597:             sql << CONCAT
598:             array_sql_append(sql, args)
599:           else
600:             literal_append(sql, args.at(0))
601:           end
602:         when 'B~''B~'
603:           sql << CAST_BITCOMP_OPEN
604:           literal_append(sql, args.at(0))
605:           sql << CAST_BITCOMP_CLOSE
606:         else
607:           super
608:         end
609:       end

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

[Source]

     # File lib/sequel/adapters/shared/mysql.rb, line 612
612:       def distinct(*args)
613:         args.empty? ? super : group(*args)
614:       end

Return the results of an EXPLAIN query as a string. Options:

:extended :Use EXPLAIN EXPTENDED instead of EXPLAIN if true.

[Source]

     # File lib/sequel/adapters/shared/mysql.rb, line 626
626:       def explain(opts=OPTS)
627:         # Load the PrettyTable class, needed for explain output
628:         Sequel.extension(:_pretty_table) unless defined?(Sequel::PrettyTable)
629: 
630:         ds = db.send(:metadata_dataset).with_sql((opts[:extended] ? EXPLAIN_EXTENDED : EXPLAIN) + select_sql).naked
631:         rows = ds.all
632:         Sequel::PrettyTable.string(rows, ds.columns)
633:       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 636
636:       def for_share
637:         lock_style(:share)
638:       end

Adds full text filter

[Source]

     # File lib/sequel/adapters/shared/mysql.rb, line 641
641:       def full_text_search(cols, terms, opts = OPTS)
642:         filter(full_text_sql(cols, terms, opts))
643:       end

MySQL specific full text search syntax.

[Source]

     # File lib/sequel/adapters/shared/mysql.rb, line 646
646:       def full_text_sql(cols, terms, opts = OPTS)
647:         terms = terms.join(' ') if terms.is_a?(Array)
648:         SQL::PlaceholderLiteralString.new((opts[:boolean] ? MATCH_AGAINST_BOOLEAN : MATCH_AGAINST), [Array(cols), terms])
649:       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 680
680:       def insert_ignore
681:         clone(:insert_ignore=>true)
682:       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 653
653:       def join_table(type, table, expr=nil, opts=OPTS, &block)
654:         type = :inner if (type == :cross) && !expr.nil?
655:         raise(Sequel::Error, "MySQL doesn't support FULL OUTER JOIN") if type == :full_outer
656:         super(type, table, expr, opts, &block)
657:       end

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

[Source]

     # File lib/sequel/adapters/shared/mysql.rb, line 661
661:       def join_type_sql(join_type)
662:         case join_type
663:         when :straight
664:           STRAIGHT_JOIN
665:         when :natural_inner
666:           NATURAL_LEFT_JOIN
667:         else
668:           super
669:         end
670:       end

MySQL specific syntax for inserting multiple values at once.

[Source]

     # File lib/sequel/adapters/shared/mysql.rb, line 708
708:       def multi_insert_sql(columns, values)
709:         sql = LiteralString.new('VALUES ')
710:         expression_list_append(sql, values.map{|r| Array(r)})
711:         [insert_sql(columns, sql)]
712:       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 703
703:       def on_duplicate_key_update(*args)
704:         clone(:on_duplicate_key_update => args)
705:       end

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

[Source]

     # File lib/sequel/adapters/shared/mysql.rb, line 715
715:       def quoted_identifier_append(sql, c)
716:         sql << BACKTICK << c.to_s.gsub(BACKTICK_RE, DOUBLE_BACKTICK) << BACKTICK
717:       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 721
721:       def supports_distinct_on?
722:         true
723:       end

MySQL supports GROUP BY WITH ROLLUP (but not CUBE)

[Source]

     # File lib/sequel/adapters/shared/mysql.rb, line 726
726:       def supports_group_rollup?
727:         true
728:       end

MySQL does not support INTERSECT or EXCEPT

[Source]

     # File lib/sequel/adapters/shared/mysql.rb, line 731
731:       def supports_intersect_except?
732:         false
733:       end

MySQL supports modifying joined datasets

[Source]

     # File lib/sequel/adapters/shared/mysql.rb, line 736
736:       def supports_modifying_joins?
737:         true
738:       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 742
742:       def supports_ordered_distinct_on?
743:         false
744:       end

MySQL supports pattern matching via regular expressions

[Source]

     # File lib/sequel/adapters/shared/mysql.rb, line 747
747:       def supports_regexp?
748:         true
749:       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 754
754:       def supports_timestamp_usecs?
755:         false
756:       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 764
764:       def update_ignore
765:         clone(:update_ignore=>true)
766:       end

[Validate]