Module | Sequel::SQLite::DatasetMethods |
In: |
lib/sequel/adapters/shared/sqlite.rb
|
Instance methods for datasets that connect to an SQLite database
SELECT_CLAUSE_METHODS | = | Dataset.clause_methods(:select, %w'distinct columns from join where group having compounds order limit') |
COMMA_SEPARATOR | = | ', '.freeze |
CONSTANT_MAP | = | {:CURRENT_DATE=>"date(CURRENT_TIMESTAMP, 'localtime')".freeze, :CURRENT_TIMESTAMP=>"datetime(CURRENT_TIMESTAMP, 'localtime')".freeze, :CURRENT_TIME=>"time(CURRENT_TIMESTAMP, 'localtime')".freeze} |
Ugly hack. Really, SQLite uses 0 for false and 1 for true but then you can‘t differentiate between integers and booleans. In filters, SQL::BooleanConstants are used more, while in other places the ruby true/false values are used more, so use 1/0 for SQL::BooleanConstants. The correct fix for this would require separate literalization paths for filters compared to other values, but that‘s more work than I want to do right now.
# File lib/sequel/adapters/shared/sqlite.rb, line 349 349: def boolean_constant_sql(constant) 350: case constant 351: when true 352: '1' 353: when false 354: '0' 355: else 356: super 357: end 358: end
SQLite does not support pattern matching via regular expressions. SQLite is case insensitive (depending on pragma), so use LIKE for ILIKE.
# File lib/sequel/adapters/shared/sqlite.rb, line 363 363: def complex_expression_sql(op, args) 364: case op 365: when :~, '!~''!~', '~*''~*', '!~*''!~*' 366: raise Error, "SQLite does not support pattern matching via regular expressions" 367: when :LIKE, 'NOT LIKE''NOT LIKE', :ILIKE, 'NOT ILIKE''NOT ILIKE' 368: # SQLite is case insensitive for ASCII, and non case sensitive for other character sets 369: "#{'NOT ' if [:'NOT LIKE', :'NOT ILIKE'].include?(op)}(#{literal(args.at(0))} LIKE #{literal(args.at(1))})" 370: else 371: super(op, args) 372: end 373: 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.
# File lib/sequel/adapters/shared/sqlite.rb, line 383 383: def delete 384: @opts[:where] ? super : filter(1=>1).delete 385: end
Return an array of strings specifying a query explanation for a SELECT of the current dataset.
# File lib/sequel/adapters/shared/sqlite.rb, line 389 389: def explain 390: db.send(:metadata_dataset).clone(:sql=>"EXPLAIN #{select_sql}"). 391: map{|x| "#{x[:addr]}|#{x[:opcode]}|#{(1..5).map{|i| x[:"p#{i}"]}.join('|')}|#{x[:comment]}"} 392: end