module Sequel::MySQL::DatasetMethods

Dataset methods shared by datasets that use MySQL databases.

Constants

MATCH_AGAINST
MATCH_AGAINST_BOOLEAN

Public Instance Methods

calc_found_rows() click to toggle source

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
    # File lib/sequel/adapters/shared/mysql.rb
677 def calc_found_rows
678   clone(:calc_found_rows => true)
679 end
complex_expression_sql_append(sql, op, args) click to toggle source
Calls superclass method
    # File lib/sequel/adapters/shared/mysql.rb
611 def complex_expression_sql_append(sql, op, args)
612   case op
613   when :IN, :"NOT IN"
614     ds = args[1]
615     if ds.is_a?(Sequel::Dataset) && ds.opts[:limit]
616       super(sql, op, [args[0], ds.from_self])
617     else
618       super
619     end
620   when :~, :'!~', :'~*', :'!~*', :LIKE, :'NOT LIKE', :ILIKE, :'NOT ILIKE'
621     if !db.mariadb? && db.server_version >= 80000 && [:~, :'!~'].include?(op)
622       func = Sequel.function(:REGEXP_LIKE, args[0], args[1], 'c')
623       func = ~func if op == :'!~'
624       return literal_append(sql, func)
625     end
626 
627     sql << '('
628     literal_append(sql, args[0])
629     sql << ' '
630     sql << 'NOT ' if [:'NOT LIKE', :'NOT ILIKE', :'!~', :'!~*'].include?(op)
631     sql << ([:~, :'!~', :'~*', :'!~*'].include?(op) ? 'REGEXP' : 'LIKE')
632     sql << ' '
633     sql << 'BINARY ' if [:~, :'!~', :LIKE, :'NOT LIKE'].include?(op)
634     literal_append(sql, args[1])
635     if [:LIKE, :'NOT LIKE', :ILIKE, :'NOT ILIKE'].include?(op)
636       sql << " ESCAPE "
637       literal_append(sql, "\\")
638     end
639     sql << ')'
640   when :'||'
641     if args.length > 1
642       sql << "CONCAT"
643       array_sql_append(sql, args)
644     else
645       literal_append(sql, args[0])
646     end
647   when :'B~'
648     sql << "CAST(~"
649     literal_append(sql, args[0])
650     sql << " AS SIGNED INTEGER)"
651   else
652     super
653   end
654 end
constant_sql_append(sql, constant) click to toggle source

MySQL's CURRENT_TIMESTAMP does not use fractional seconds, even if the database itself supports fractional seconds. If MySQL 5.6.4+ is being used, use a value that will return fractional seconds.

Calls superclass method
    # File lib/sequel/adapters/shared/mysql.rb
660 def constant_sql_append(sql, constant)
661   if constant == :CURRENT_TIMESTAMP && supports_timestamp_usecs?
662     sql << 'CURRENT_TIMESTAMP(6)'
663   else
664     super
665   end
666 end
delete_from(*tables) click to toggle source

Sets up the select methods to delete from if deleting from a joined dataset:

DB[:a].join(:b, a_id: :id).delete
# DELETE a FROM a INNER JOIN b ON (b.a_id = a.id)

DB[:a].join(:b, a_id: :id).delete_from(:a, :b).delete
# DELETE a, b FROM a INNER JOIN b ON (b.a_id = a.id)
    # File lib/sequel/adapters/shared/mysql.rb
689 def delete_from(*tables)
690   clone(:delete_from=>tables)
691 end
distinct(*args) click to toggle source

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

Calls superclass method
    # File lib/sequel/adapters/shared/mysql.rb
669 def distinct(*args)
670   args.empty? ? super : group(*args)
671 end
explain(opts=OPTS) click to toggle source

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

:extended

Use EXPLAIN EXTENDED instead of EXPLAIN if true.

    # File lib/sequel/adapters/shared/mysql.rb
695 def explain(opts=OPTS)
696   # Load the PrettyTable class, needed for explain output
697   Sequel.extension(:_pretty_table) unless defined?(Sequel::PrettyTable)
698 
699   ds = db.send(:metadata_dataset).with_sql(((opts[:extended] && (db.mariadb? || db.server_version < 50700)) ? 'EXPLAIN EXTENDED ' : 'EXPLAIN ') + select_sql).naked
700   rows = ds.all
701   Sequel::PrettyTable.string(rows, ds.columns)
702 end
for_share() click to toggle source

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

    # File lib/sequel/adapters/shared/mysql.rb
705 def for_share
706   lock_style(:share)
707 end
full_text_sql(cols, terms, opts = OPTS) click to toggle source

MySQL specific full text search syntax.

    # File lib/sequel/adapters/shared/mysql.rb
715 def full_text_sql(cols, terms, opts = OPTS)
716   terms = terms.join(' ') if terms.is_a?(Array)
717   SQL::PlaceholderLiteralString.new((opts[:boolean] ? MATCH_AGAINST_BOOLEAN : MATCH_AGAINST), [Array(cols), terms])
718 end
insert_ignore() click to toggle source

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)
    # File lib/sequel/adapters/shared/mysql.rb
728 def insert_ignore
729   clone(:insert_ignore=>true)
730 end
on_duplicate_key_update(*args) click to toggle source

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. If you pass a hash you can customize the values (for example, to increment a numeric field).

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)

dataset.on_duplicate_key_update(
  value: Sequel.lit('value + VALUES(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=value + VALUES(value)
    # File lib/sequel/adapters/shared/mysql.rb
761 def on_duplicate_key_update(*args)
762   clone(:on_duplicate_key_update => args)
763 end
quoted_identifier_append(sql, c) click to toggle source

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

    # File lib/sequel/adapters/shared/mysql.rb
766 def quoted_identifier_append(sql, c)
767   sql << '`' << c.to_s.gsub('`', '``') << '`'
768 end
supports_cte?(type=:select) click to toggle source

MariaDB 10.2+ and MySQL 8+ support CTEs

    # File lib/sequel/adapters/shared/mysql.rb
771 def supports_cte?(type=:select)
772   if db.mariadb?
773     type == :select && db.server_version >= 100200
774   else
775     case type
776     when :select, :update, :delete
777       db.server_version >= 80000
778     end
779   end
780 end
supports_derived_column_lists?() click to toggle source

MySQL does not support derived column lists

    # File lib/sequel/adapters/shared/mysql.rb
783 def supports_derived_column_lists?
784   false
785 end
supports_distinct_on?() click to toggle source

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

    # File lib/sequel/adapters/shared/mysql.rb
789 def supports_distinct_on?
790   true
791 end
supports_group_rollup?() click to toggle source

MySQL supports GROUP BY WITH ROLLUP (but not CUBE)

    # File lib/sequel/adapters/shared/mysql.rb
794 def supports_group_rollup?
795   true
796 end
supports_intersect_except?() click to toggle source

MariaDB 10.3+ supports INTERSECT or EXCEPT

    # File lib/sequel/adapters/shared/mysql.rb
799 def supports_intersect_except?
800   db.mariadb? && db.server_version >= 100300
801 end
supports_limits_in_correlated_subqueries?() click to toggle source

MySQL does not support limits in correlated subqueries (or any subqueries that use IN).

    # File lib/sequel/adapters/shared/mysql.rb
804 def supports_limits_in_correlated_subqueries?
805   false
806 end
supports_modifying_joins?() click to toggle source

MySQL supports modifying joined datasets

    # File lib/sequel/adapters/shared/mysql.rb
809 def supports_modifying_joins?
810   true
811 end
supports_nowait?() click to toggle source

MySQL 8+ and MariaDB 10.3+ support NOWAIT.

    # File lib/sequel/adapters/shared/mysql.rb
814 def supports_nowait?
815   db.server_version >= (db.mariadb? ? 100300 : 80000)
816 end
supports_ordered_distinct_on?() click to toggle source

MySQL's DISTINCT ON emulation using GROUP BY does not respect the query's ORDER BY clause.

    # File lib/sequel/adapters/shared/mysql.rb
820 def supports_ordered_distinct_on?
821   false
822 end
supports_regexp?() click to toggle source

MySQL supports pattern matching via regular expressions

    # File lib/sequel/adapters/shared/mysql.rb
825 def supports_regexp?
826   true
827 end
supports_skip_locked?() click to toggle source

MySQL 8+ supports SKIP LOCKED.

    # File lib/sequel/adapters/shared/mysql.rb
830 def supports_skip_locked?
831   !db.mariadb? && db.server_version >= 80000
832 end
supports_timestamp_usecs?() click to toggle source

Check the database setting for whether fractional timestamps are suppported.

    # File lib/sequel/adapters/shared/mysql.rb
836 def supports_timestamp_usecs?
837   db.supports_timestamp_usecs?
838 end
supports_window_clause?() click to toggle source

MySQL 8+ supports WINDOW clause.

    # File lib/sequel/adapters/shared/mysql.rb
841 def supports_window_clause?
842   !db.mariadb? && db.server_version >= 80000
843 end
supports_window_functions?() click to toggle source

MariaDB 10.2+ and MySQL 8+ support window functions

    # File lib/sequel/adapters/shared/mysql.rb
846 def supports_window_functions?
847   db.server_version >= (db.mariadb? ? 100200 : 80000)
848 end
update_ignore() click to toggle source

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
    # File lib/sequel/adapters/shared/mysql.rb
856 def update_ignore
857   clone(:update_ignore=>true)
858 end

Private Instance Methods

check_not_limited!(type) click to toggle source

Allow update and delete for limited datasets, unless there is an offset.

Calls superclass method
    # File lib/sequel/adapters/shared/mysql.rb
863 def check_not_limited!(type)
864   super if type == :truncate || @opts[:offset]
865 end
delete_from_sql(sql) click to toggle source

Consider the first table in the joined dataset is the table to delete from, but include the others for the purposes of selecting rows.

Calls superclass method
    # File lib/sequel/adapters/shared/mysql.rb
869 def delete_from_sql(sql)
870   if joined_dataset?
871     sql << ' '
872     tables = @opts[:delete_from] || @opts[:from][0..0]
873     source_list_append(sql, tables)
874     sql << ' FROM '
875     source_list_append(sql, @opts[:from])
876     select_join_sql(sql)
877   else
878     super
879   end
880 end
delete_limit_sql(sql)
Alias for: limit_sql
insert_columns_sql(sql) click to toggle source

MySQL doesn't use the SQL standard DEFAULT VALUES.

Calls superclass method
    # File lib/sequel/adapters/shared/mysql.rb
883 def insert_columns_sql(sql)
884   values = opts[:values]
885   if values.is_a?(Array) && values.empty?
886     sql << " ()"
887   else
888     super
889   end
890 end
insert_ignore_sql(sql) click to toggle source

MySQL supports INSERT IGNORE INTO

    # File lib/sequel/adapters/shared/mysql.rb
893 def insert_ignore_sql(sql)
894   sql << " IGNORE" if opts[:insert_ignore]
895 end
insert_on_duplicate_key_update_sql(sql) click to toggle source

MySQL supports INSERT … ON DUPLICATE KEY UPDATE

    # File lib/sequel/adapters/shared/mysql.rb
903 def insert_on_duplicate_key_update_sql(sql)
904   if update_cols = opts[:on_duplicate_key_update]
905     update_vals = nil
906 
907     if update_cols.empty?
908       update_cols = columns
909     elsif update_cols.last.is_a?(Hash)
910       update_vals = update_cols.last
911       update_cols = update_cols[0..-2]
912     end
913 
914     sql << " ON DUPLICATE KEY UPDATE "
915     c = false
916     co = ', '
917     values = '=VALUES('
918     endp = ')'
919     update_cols.each do |col|
920       sql << co if c
921       quote_identifier_append(sql, col)
922       sql << values
923       quote_identifier_append(sql, col)
924       sql << endp
925       c ||= true
926     end
927     if update_vals
928       eq = '='
929       update_vals.map do |col,v| 
930         sql << co if c
931         quote_identifier_append(sql, col)
932         sql << eq
933         literal_append(sql, v)
934         c ||= true
935       end
936     end
937   end
938 end
insert_values_sql(sql) click to toggle source

MySQL doesn't use the standard DEFAULT VALUES for empty values.

Calls superclass method
    # File lib/sequel/adapters/shared/mysql.rb
941 def insert_values_sql(sql)
942   values = opts[:values]
943   if values.is_a?(Array) && values.empty?
944     sql << " VALUES ()"
945   else
946     super
947   end
948 end
join_type_sql(join_type) click to toggle source

Transforms :straight to STRAIGHT_JOIN.

Calls superclass method
    # File lib/sequel/adapters/shared/mysql.rb
951 def join_type_sql(join_type)
952   if join_type == :straight
953     'STRAIGHT_JOIN'
954   else
955     super
956   end
957 end
limit_sql(sql) click to toggle source

MySQL allows a LIMIT in DELETE and UPDATE statements.

    # File lib/sequel/adapters/shared/mysql.rb
960 def limit_sql(sql)
961   if l = @opts[:limit]
962     sql << " LIMIT "
963     literal_append(sql, l)
964   end
965 end
literal_blob_append(sql, v) click to toggle source

MySQL uses a preceding X for hex escaping strings

    # File lib/sequel/adapters/shared/mysql.rb
970 def literal_blob_append(sql, v)
971   if v.empty?
972     sql << "''"
973   else
974     sql << "0x" << v.unpack("H*").first
975   end
976 end
literal_false() click to toggle source

Use 0 for false on MySQL

    # File lib/sequel/adapters/shared/mysql.rb
979 def literal_false
980   '0'
981 end
literal_float(v) click to toggle source

Raise error for infinitate and NaN values

Calls superclass method
    # File lib/sequel/adapters/shared/mysql.rb
984 def literal_float(v)
985   if v.infinite? || v.nan?
986     raise InvalidValue, "Infinite floats and NaN values are not valid on MySQL"
987   else
988     super
989   end
990 end
literal_string_append(sql, v) click to toggle source

SQL fragment for String. Doubles \ and ' by default.

    # File lib/sequel/adapters/shared/mysql.rb
993 def literal_string_append(sql, v)
994   sql << "'" << v.gsub("\\", "\\\\\\\\").gsub("'", "''") << "'"
995 end
literal_true() click to toggle source

Use 1 for true on MySQL

     # File lib/sequel/adapters/shared/mysql.rb
 998 def literal_true
 999   '1'
1000 end
multi_insert_sql_strategy() click to toggle source

MySQL supports multiple rows in VALUES in INSERT.

     # File lib/sequel/adapters/shared/mysql.rb
1003 def multi_insert_sql_strategy
1004   :values
1005 end
non_sql_option?(key) click to toggle source
Calls superclass method
     # File lib/sequel/adapters/shared/mysql.rb
1007 def non_sql_option?(key)
1008   super || key == :insert_ignore || key == :update_ignore || key == :on_duplicate_key_update
1009 end
requires_emulating_nulls_first?() click to toggle source

MySQL does not natively support NULLS FIRST/LAST.

     # File lib/sequel/adapters/shared/mysql.rb
1012 def requires_emulating_nulls_first?
1013   true
1014 end
select_calc_found_rows_sql(sql) click to toggle source

MySQL specific SQL_CALC_FOUND_ROWS option

     # File lib/sequel/adapters/shared/mysql.rb
1046 def select_calc_found_rows_sql(sql)
1047   sql << ' SQL_CALC_FOUND_ROWS' if opts[:calc_found_rows]
1048 end
select_lock_sql(sql) click to toggle source

Support FOR SHARE locking when using the :share lock style. Use SKIP LOCKED if skipping locked rows.

Calls superclass method
     # File lib/sequel/adapters/shared/mysql.rb
1024 def select_lock_sql(sql)
1025   lock = @opts[:lock]
1026   if lock == :share
1027     if !db.mariadb? && db.server_version >= 80000
1028       sql << ' FOR SHARE'
1029     else
1030       sql << ' LOCK IN SHARE MODE'
1031     end
1032   else
1033     super
1034   end
1035 
1036   if lock
1037     if @opts[:skip_locked]
1038       sql << " SKIP LOCKED"
1039     elsif @opts[:nowait]
1040       sql << " NOWAIT"
1041     end
1042   end
1043 end
select_only_offset_sql(sql) click to toggle source
     # File lib/sequel/adapters/shared/mysql.rb
1016 def select_only_offset_sql(sql)
1017   sql << " LIMIT "
1018   literal_append(sql, @opts[:offset])
1019   sql << ",18446744073709551615"
1020 end
select_with_sql_base() click to toggle source

Use WITH RECURSIVE instead of WITH if any of the CTEs is recursive

Calls superclass method
     # File lib/sequel/adapters/shared/mysql.rb
1051 def select_with_sql_base
1052   opts[:with].any?{|w| w[:recursive]} ? "WITH RECURSIVE " : super
1053 end
update_ignore_sql(sql) click to toggle source

MySQL supports UPDATE IGNORE

    # File lib/sequel/adapters/shared/mysql.rb
898 def update_ignore_sql(sql)
899   sql << " IGNORE" if opts[:update_ignore]
900 end
update_limit_sql(sql)
Alias for: limit_sql
uses_with_rollup?() click to toggle source

MySQL uses WITH ROLLUP syntax.

     # File lib/sequel/adapters/shared/mysql.rb
1056 def uses_with_rollup?
1057   true
1058 end