Module Sequel::SQLite::DatasetMethods
In: lib/sequel/adapters/shared/sqlite.rb

Instance methods for datasets that connect to an SQLite database

Methods

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

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 244
244:       def complex_expression_sql(op, args)
245:         case op
246:         when :~, '!~''!~', '~*''~*', '!~*''!~*'
247:           raise Error, "SQLite does not support pattern matching via regular expressions"
248:         when :LIKE, 'NOT LIKE''NOT LIKE', :ILIKE, 'NOT ILIKE''NOT ILIKE'
249:           # SQLite is case insensitive for ASCII, and non case sensitive for other character sets
250:           "#{'NOT ' if [:'NOT LIKE', :'NOT ILIKE'].include?(op)}(#{literal(args.at(0))} LIKE #{literal(args.at(1))})"
251:         else
252:           super(op, args)
253:         end
254:       end

MSSQL doesn‘t support the SQL standard CURRENT_DATE or CURRENT_TIME

[Source]

     # File lib/sequel/adapters/shared/sqlite.rb, line 257
257:       def constant_sql(constant)
258:         CONSTANT_MAP[constant] || super
259:       end

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 264
264:       def delete
265:         @opts[:where] ? super : filter(1=>1).delete
266:       end

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 270
270:       def explain
271:         db.send(:metadata_dataset).clone(:sql=>"EXPLAIN #{select_sql}").
272:           map{|x| "#{x[:addr]}|#{x[:opcode]}|#{(1..5).map{|i| x[:"p#{i}"]}.join('|')}|#{x[:comment]}"}
273:       end

HAVING requires GROUP BY on SQLite

[Source]

     # File lib/sequel/adapters/shared/sqlite.rb, line 276
276:       def having(*cond, &block)
277:         raise(InvalidOperation, "Can only specify a HAVING clause on a grouped dataset") unless @opts[:group]
278:         super
279:       end

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

[Source]

     # File lib/sequel/adapters/shared/sqlite.rb, line 282
282:       def quoted_identifier(c)
283:         "`#{c}`"
284:       end

SQLite does not support INTERSECT ALL or EXCEPT ALL

[Source]

     # File lib/sequel/adapters/shared/sqlite.rb, line 287
287:       def supports_intersect_except_all?
288:         false
289:       end

SQLite does not support IS TRUE

[Source]

     # File lib/sequel/adapters/shared/sqlite.rb, line 292
292:       def supports_is_true?
293:         false
294:       end

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

[Source]

     # File lib/sequel/adapters/shared/sqlite.rb, line 297
297:       def supports_multiple_column_in?
298:         false
299:       end

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

[Source]

     # File lib/sequel/adapters/shared/sqlite.rb, line 303
303:       def supports_timestamp_timezones?
304:         true
305:       end

[Validate]