Sequel::SQLite::DatasetMethods

Included modules

Constants

CONSTANT_MAP	=	{:CURRENT_DATE=>"date(CURRENT_TIMESTAMP, 'localtime')".freeze, :CURRENT_TIMESTAMP=>"datetime(CURRENT_TIMESTAMP, 'localtime')".freeze, :CURRENT_TIME=>"time(CURRENT_TIMESTAMP, 'localtime')".freeze}.freeze
EXTRACT_MAP	=	{:year=>"'%Y'", :month=>"'%m'", :day=>"'%d'", :hour=>"'%H'", :minute=>"'%M'", :second=>"'%f'"}.freeze
INSERT_CONFLICT_RESOLUTIONS	=	%w'ROLLBACK ABORT FAIL IGNORE REPLACE'.each(&:freeze).freeze	The allowed values for `insert_conflict`

Public Instance methods

cast_sql_append(sql, expr, type)

[show source]

    # File lib/sequel/adapters/shared/sqlite.rb
598 def cast_sql_append(sql, expr, type)
599   if type == Time or type == DateTime
600     sql << "datetime("
601     literal_append(sql, expr)
602     sql << ')'
603   elsif type == Date
604     sql << "date("
605     literal_append(sql, expr)
606     sql << ')'
607   else
608     super
609   end
610 end

complex_expression_sql_append(sql, op, args)

SQLite doesn’t support a NOT LIKE b, you need to use NOT (a LIKE b). It doesn’t support xor, power, or the extract function natively, so those have to be emulated.

[show source]

    # File lib/sequel/adapters/shared/sqlite.rb
614 def complex_expression_sql_append(sql, op, args)
615   case op
616   when :"NOT LIKE", :"NOT ILIKE"
617     sql << 'NOT '
618     complex_expression_sql_append(sql, (op == :"NOT ILIKE" ? :ILIKE : :LIKE), args)
619   when :^
620     complex_expression_arg_pairs_append(sql, args){|a, b| Sequel.lit(["((~(", " & ", ")) & (", " | ", "))"], a, b, a, b)}
621   when :**
622     unless (exp = args[1]).is_a?(Integer)
623       raise(Sequel::Error, "can only emulate exponentiation on SQLite if exponent is an integer, given #{exp.inspect}")
624     end
625     case exp
626     when 0
627       sql << '1'
628     else
629       sql << '('
630       arg = args[0]
631       if exp < 0
632         invert = true
633         exp = exp.abs
634         sql << '(1.0 / ('
635       end
636       (exp - 1).times do 
637         literal_append(sql, arg)
638         sql << " * "
639       end
640       literal_append(sql, arg)
641       sql << ')'
642       if invert
643         sql << "))"
644       end
645     end
646   when :extract
647     part = args[0]
648     raise(Sequel::Error, "unsupported extract argument: #{part.inspect}") unless format = EXTRACT_MAP[part]
649     sql << "CAST(strftime(" << format << ', '
650     literal_append(sql, args[1])
651     sql << ') AS ' << (part == :second ? 'NUMERIC' : 'INTEGER') << ')'
652   else
653     super
654   end
655 end

constant_sql_append(sql, constant)

SQLite has CURRENT_TIMESTAMP and related constants in UTC instead of in localtime, so convert those constants to local time.

[show source]

    # File lib/sequel/adapters/shared/sqlite.rb
659 def constant_sql_append(sql, constant)
660   if (c = CONSTANT_MAP[constant]) && !db.current_timestamp_utc
661     sql << c
662   else
663     super
664   end
665 end

delete(&block)

SQLite performs a TRUNCATE style DELETE if no filter is specified. Since we want to always return the count of records, add a condition that is always true and then delete.

[show source]

    # File lib/sequel/adapters/shared/sqlite.rb
670 def delete(&block)
671   @opts[:where] ? super : where(1=>1).delete(&block)
672 end

empty?()

Always return false when using VALUES

[show source]

    # File lib/sequel/adapters/shared/sqlite.rb
675 def empty?
676   return false if @opts[:values]
677   super
678 end

explain(opts=nil)

Return an array of strings specifying a query explanation for a SELECT of the current dataset. Currently, the options are ignored, but it accepts options to be compatible with other adapters.

[show source]

    # File lib/sequel/adapters/shared/sqlite.rb
683 def explain(opts=nil)
684   # Load the PrettyTable class, needed for explain output
685   Sequel.extension(:_pretty_table) unless defined?(Sequel::PrettyTable)
686 
687   ds = db.send(:metadata_dataset).clone(:sql=>"EXPLAIN #{select_sql}")
688   rows = ds.all
689   Sequel::PrettyTable.string(rows, ds.columns)
690 end

having(*cond)

HAVING requires GROUP BY on SQLite

[show source]

    # File lib/sequel/adapters/shared/sqlite.rb
693 def having(*cond)
694   raise(InvalidOperation, "Can only specify a HAVING clause on a grouped dataset") if !@opts[:group] && db.sqlite_version < 33900
695   super
696 end

insert_conflict(opts = :ignore)

Handle uniqueness violations when inserting, by using a specified resolution algorithm. With no options, uses INSERT OR REPLACE. SQLite supports the following conflict resolution algoriths: ROLLBACK, ABORT, FAIL, IGNORE and REPLACE.

On SQLite 3.24.0+, you can pass a hash to use an ON CONFLICT clause. With out :update option, uses ON CONFLICT DO NOTHING. Options:

:conflict_where	The index filter, when using a partial index to determine uniqueness.
:target	The column name or expression to handle uniqueness violations on.
:update	A hash of columns and values to set. Uses ON CONFLICT DO UPDATE.
:update_where	A WHERE condition to use for the update.

Examples:

DB[:table].insert_conflict.insert(a: 1, b: 2)
# INSERT OR IGNORE INTO TABLE (a, b) VALUES (1, 2)

DB[:table].insert_conflict(:replace).insert(a: 1, b: 2)
# INSERT OR REPLACE INTO TABLE (a, b) VALUES (1, 2)

DB[:table].insert_conflict({}).insert(a: 1, b: 2)
# INSERT INTO TABLE (a, b) VALUES (1, 2)
# ON CONFLICT DO NOTHING

DB[:table].insert_conflict(target: :a).insert(a: 1, b: 2)
# INSERT INTO TABLE (a, b) VALUES (1, 2)
# ON CONFLICT (a) DO NOTHING

DB[:table].insert_conflict(target: :a, conflict_where: {c: true}).insert(a: 1, b: 2)
# INSERT INTO TABLE (a, b) VALUES (1, 2)
# ON CONFLICT (a) WHERE (c IS TRUE) DO NOTHING

DB[:table].insert_conflict(target: :a, update: {b: Sequel[:excluded][:b]}).insert(a: 1, b: 2)
# INSERT INTO TABLE (a, b) VALUES (1, 2)
# ON CONFLICT (a) DO UPDATE SET b = excluded.b

DB[:table].insert_conflict(target: :a,
  update: {b: Sequel[:excluded][:b]}, update_where: {Sequel[:table][:status_id] => 1}).insert(a: 1, b: 2)
# INSERT INTO TABLE (a, b) VALUES (1, 2)
# ON CONFLICT (a) DO UPDATE SET b = excluded.b WHERE (table.status_id = 1)

[show source]

    # File lib/sequel/adapters/shared/sqlite.rb
771 def insert_conflict(opts = :ignore)
772   case opts
773   when Symbol, String
774     unless INSERT_CONFLICT_RESOLUTIONS.include?(opts.to_s.upcase)
775       raise Error, "Invalid symbol or string passed to Dataset#insert_conflict: #{opts.inspect}.  The allowed values are: :rollback, :abort, :fail, :ignore, or :replace"
776     end
777     clone(:insert_conflict => opts)
778   when Hash
779     clone(:insert_on_conflict => opts)
780   else
781     raise Error, "Invalid value passed to Dataset#insert_conflict: #{opts.inspect}, should use a symbol or a hash"
782   end
783 end

insert_ignore()

Ignore uniqueness/exclusion violations when inserting, using INSERT OR IGNORE. Exists mostly for compatibility to MySQL’s insert_ignore. Example:

DB[:table].insert_ignore.insert(a: 1, b: 2)
# INSERT OR IGNORE INTO TABLE (a, b) VALUES (1, 2)

[show source]

    # File lib/sequel/adapters/shared/sqlite.rb
790 def insert_ignore
791   insert_conflict(:ignore)
792 end

insert_select(*values)

Support insert select for associations, so that the model code can use returning instead of a separate query.

[show source]

    # File lib/sequel/adapters/shared/sqlite.rb
700 def insert_select(*values)
701   return unless supports_insert_select?
702   # Handle case where query does not return a row
703   server?(:default).with_sql_first(insert_select_sql(*values)) || false
704 end

insert_select_sql(*values)

The SQL to use for an insert_select, adds a RETURNING clause to the insert unless the RETURNING clause is already present.

[show source]

    # File lib/sequel/adapters/shared/sqlite.rb
708 def insert_select_sql(*values)
709   ds = opts[:returning] ? self : returning
710   ds.insert_sql(*values)
711 end

quoted_identifier_append(sql, c)

SQLite uses the nonstandard ‘ (backtick) for quoting identifiers.

[show source]

    # File lib/sequel/adapters/shared/sqlite.rb
714 def quoted_identifier_append(sql, c)
715   sql << '`' << c.to_s.gsub('`', '``') << '`'
716 end

returning(*values)

Automatically add aliases to RETURNING values to work around SQLite bug.

[show source]

    # File lib/sequel/adapters/shared/sqlite.rb
795 def returning(*values)
796   return super if values.empty?
797   raise Error, "RETURNING is not supported on #{db.database_type}" unless supports_returning?(:insert)
798   clone(:returning=>_returning_values(values).freeze)
799 end

select(*cols)

When a qualified column is selected on SQLite and the qualifier is a subselect, the column name used is the full qualified name (including the qualifier) instead of just the column name. To get correct column names, you must use an alias.

[show source]

    # File lib/sequel/adapters/shared/sqlite.rb
722 def select(*cols)
723   if ((f = @opts[:from]) && f.any?{|t| t.is_a?(Dataset) || (t.is_a?(SQL::AliasedExpression) && t.expression.is_a?(Dataset))}) || ((j = @opts[:join]) && j.any?{|t| t.table.is_a?(Dataset)})
724     super(*cols.map{|c| alias_qualified_column(c)})
725   else
726     super
727   end
728 end

supports_cte?(type=:select)

SQLite 3.8.3+ supports common table expressions.

[show source]

    # File lib/sequel/adapters/shared/sqlite.rb
802 def supports_cte?(type=:select)
803   db.sqlite_version >= 30803
804 end

supports_cte_in_subqueries?()

SQLite supports CTEs in subqueries if it supports CTEs.

[show source]

    # File lib/sequel/adapters/shared/sqlite.rb
807 def supports_cte_in_subqueries?
808   supports_cte?
809 end

supports_deleting_joins?()

SQLite does not support deleting from a joined dataset

[show source]

    # File lib/sequel/adapters/shared/sqlite.rb
817 def supports_deleting_joins?
818   false
819 end

supports_derived_column_lists?()

SQLite does not support table aliases with column aliases

[show source]

    # File lib/sequel/adapters/shared/sqlite.rb
812 def supports_derived_column_lists?
813   false
814 end

supports_intersect_except_all?()

SQLite does not support INTERSECT ALL or EXCEPT ALL

[show source]

    # File lib/sequel/adapters/shared/sqlite.rb
822 def supports_intersect_except_all?
823   false
824 end

supports_is_true?()

SQLite does not support IS TRUE

[show source]

    # File lib/sequel/adapters/shared/sqlite.rb
827 def supports_is_true?
828   false
829 end

supports_modifying_joins?()

SQLite 3.33.0 supports modifying joined datasets

[show source]

    # File lib/sequel/adapters/shared/sqlite.rb
832 def supports_modifying_joins?
833   db.sqlite_version >= 33300
834 end

supports_multiple_column_in?()

SQLite does not support multiple columns for the IN/NOT IN operators

[show source]

    # File lib/sequel/adapters/shared/sqlite.rb
837 def supports_multiple_column_in?
838   false
839 end

supports_returning?(_)

SQLite 3.35.0 supports RETURNING on INSERT/UPDATE/DELETE.

[show source]

    # File lib/sequel/adapters/shared/sqlite.rb
842 def supports_returning?(_)
843   db.sqlite_version >= 33500
844 end

supports_timestamp_timezones?()

SQLite supports timezones in literal timestamps, since it stores them as text. But using timezones in timestamps breaks SQLite datetime functions, so we allow the user to override the default per database.

[show source]

    # File lib/sequel/adapters/shared/sqlite.rb
849 def supports_timestamp_timezones?
850   db.use_timestamp_timezones?
851 end

supports_where_true?()

SQLite cannot use WHERE ‘t’.

[show source]

    # File lib/sequel/adapters/shared/sqlite.rb
854 def supports_where_true?
855   false
856 end

supports_window_clause?()

SQLite 3.28+ supports the WINDOW clause.

[show source]

    # File lib/sequel/adapters/shared/sqlite.rb
859 def supports_window_clause?
860   db.sqlite_version >= 32800
861 end

supports_window_function_frame_option?(option)

SQLite 3.28.0+ supports all window frame options that Sequel supports

[show source]

    # File lib/sequel/adapters/shared/sqlite.rb
872 def supports_window_function_frame_option?(option)
873   db.sqlite_version >= 32800 ? true : super
874 end

supports_window_functions?()

SQLite 3.25+ supports window functions. However, support is only enabled on SQLite 3.26.0+ because internal Sequel usage of window functions to implement eager loading of limited associations triggers an SQLite crash bug in versions 3.25.0-3.25.3.

[show source]

    # File lib/sequel/adapters/shared/sqlite.rb
867 def supports_window_functions?
868   db.sqlite_version >= 32600
869 end

module Sequel::SQLite::DatasetMethods

Methods

Public Instance

Included modules

Constants

Public Instance methods