Module: Sequel::SQLite::DatasetMethods

Constants

SELECT_CLAUSE_METHODS	=	Dataset.clause_methods(:select, %w'distinct columns from join where group having compounds order limit')
CONSTANT_MAP	=	{:CURRENT_DATE=>"date(CURRENT_TIMESTAMP, 'localtime')".freeze, :CURRENT_TIMESTAMP=>"datetime(CURRENT_TIMESTAMP, 'localtime')".freeze, :CURRENT_TIME=>"time(CURRENT_TIMESTAMP, 'localtime')".freeze}

Public Instance methods

complex_expression_sql(op, args)

SQLite does not support pattern matching via regular expressions. SQLite is case insensitive (depending on pragma), so use LIKE for ILIKE.

[Source]

     # File lib/sequel/adapters/shared/sqlite.rb, line 320
320:       def complex_expression_sql(op, args)
321:         case op
322:         when :~, '!~''!~', '~*''~*', '!~*''!~*'
323:           raise Error, "SQLite does not support pattern matching via regular expressions"
324:         when :LIKE, 'NOT LIKE''NOT LIKE', :ILIKE, 'NOT ILIKE''NOT ILIKE'
325:           # SQLite is case insensitive for ASCII, and non case sensitive for other character sets
326:           "#{'NOT ' if [:'NOT LIKE', :'NOT ILIKE'].include?(op)}(#{literal(args.at(0))} LIKE #{literal(args.at(1))})"
327:         else
328:           super(op, args)
329:         end
330:       end

constant_sql(constant)

MSSQL doesn‘t support the SQL standard CURRENT_DATE or CURRENT_TIME

[Source]

     # File lib/sequel/adapters/shared/sqlite.rb, line 333
333:       def constant_sql(constant)
334:         CONSTANT_MAP[constant] || super
335:       end

delete()

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.

[Source]

     # File lib/sequel/adapters/shared/sqlite.rb, line 340
340:       def delete
341:         @opts[:where] ? super : filter(1=>1).delete
342:       end

explain()

Return an array of strings specifying a query explanation for a SELECT of the current dataset.

[Source]

     # File lib/sequel/adapters/shared/sqlite.rb, line 346
346:       def explain
347:         db.send(:metadata_dataset).clone(:sql=>"EXPLAIN #{select_sql}").
348:           map{|x| "#{x[:addr]}|#{x[:opcode]}|#{(1..5).map{|i| x[:"p#{i}"]}.join('|')}|#{x[:comment]}"}
349:       end

having(*cond, &block)

HAVING requires GROUP BY on SQLite

[Source]

     # File lib/sequel/adapters/shared/sqlite.rb, line 352
352:       def having(*cond, &block)
353:         raise(InvalidOperation, "Can only specify a HAVING clause on a grouped dataset") unless @opts[:group]
354:         super
355:       end

quoted_identifier(c)

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

[Source]

     # File lib/sequel/adapters/shared/sqlite.rb, line 358
358:       def quoted_identifier(c)
359:         "`#{c}`"
360:       end

supports_intersect_except_all?()

SQLite does not support INTERSECT ALL or EXCEPT ALL

[Source]

     # File lib/sequel/adapters/shared/sqlite.rb, line 363
363:       def supports_intersect_except_all?
364:         false
365:       end

supports_is_true?()

SQLite does not support IS TRUE

[Source]

     # File lib/sequel/adapters/shared/sqlite.rb, line 368
368:       def supports_is_true?
369:         false
370:       end

supports_multiple_column_in?()

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

[Source]

     # File lib/sequel/adapters/shared/sqlite.rb, line 373
373:       def supports_multiple_column_in?
374:         false
375:       end

supports_timestamp_timezones?()

SQLite supports timezones in literal timestamps, since it stores them as text.

[Source]

     # File lib/sequel/adapters/shared/sqlite.rb, line 379
379:       def supports_timestamp_timezones?
380:         true
381:       end