class Sequel::SQL::Function
Represents an SQL
function call.
Constants
- COMMA_ARRAY
- DISTINCT
- WILDCARD
Attributes
The array of arguments to pass to the function (may be blank)
The SQL
function to call
Options for this function
Public Class Methods
Set the name and args for the function
# File lib/sequel/sql.rb 1376 def initialize(name, *args) 1377 _initialize(name, args, OPTS) 1378 end
Public Instance Methods
If no arguments are given, return a new function with the wildcard prepended to the arguments.
Sequel.function(:count).* # count(*)
# File lib/sequel/sql.rb 1388 def *(ce=(arg=false;nil)) 1389 if arg == false 1390 raise Error, "Cannot apply * to functions with arguments" unless args.empty? 1391 with_opts(:"*"=>true) 1392 else 1393 super(ce) 1394 end 1395 end
Return a new function with DISTINCT
before the method arguments.
Sequel.function(:count, :col).distinct # count(DISTINCT col)
# File lib/sequel/sql.rb 1400 def distinct 1401 with_opts(:distinct=>true) 1402 end
Return a new function with FILTER added to it, for filtered aggregate functions:
Sequel.function(:foo, :col).filter(a: 1) # foo(col) FILTER (WHERE (a = 1))
# File lib/sequel/sql.rb 1408 def filter(*args, &block) 1409 if args.length == 1 1410 args = args.first 1411 else 1412 args.freeze 1413 end 1414 1415 with_opts(:filter=>args, :filter_block=>block) 1416 end
Return a function which will use LATERAL when literalized:
Sequel.function(:foo, :col).lateral # LATERAL foo(col)
# File lib/sequel/sql.rb 1421 def lateral 1422 with_opts(:lateral=>true) 1423 end
Return a new function where the function will be ordered. Only useful for aggregate functions that are order dependent.
Sequel.function(:foo, :a).order(:a, Sequel.desc(:b)) # foo(a ORDER BY a, b DESC)
# File lib/sequel/sql.rb 1429 def order(*args) 1430 with_opts(:order=>args.freeze) 1431 end
Return a new function with an OVER clause (making it a window function). See Sequel::SQL::Window
for the list of options over
can receive.
Sequel.function(:row_number).over(partition: :col) # row_number() OVER (PARTITION BY col)
# File lib/sequel/sql.rb 1437 def over(window=OPTS) 1438 raise Error, "function already has a window applied to it" if opts[:over] 1439 window = Window.new(window) unless window.is_a?(Window) 1440 with_opts(:over=>window) 1441 end
Return a new function where the function name will be quoted if the database supports quoted functions:
Sequel.function(:foo).quoted # "foo"()
# File lib/sequel/sql.rb 1447 def quoted 1448 with_opts(:quoted=>true) 1449 end
Return a new function where the function name will not be quoted even if the database supports quoted functions:
Sequel[:foo][:bar].function.unquoted # foo.bar()
# File lib/sequel/sql.rb 1455 def unquoted 1456 with_opts(:quoted=>false) 1457 end
Return a new function that will use WITH ORDINALITY to also return a row number for every row the function returns:
Sequel.function(:foo).with_ordinality # foo() WITH ORDINALITY
# File lib/sequel/sql.rb 1463 def with_ordinality 1464 with_opts(:with_ordinality=>true) 1465 end
Return a new function that uses WITHIN GROUP ordered by the given expression, useful for ordered-set and hypothetical-set aggregate functions:
Sequel.function(:rank, :a).within_group(:b, :c) # rank(a) WITHIN GROUP (ORDER BY b, c)
# File lib/sequel/sql.rb 1472 def within_group(*expressions) 1473 with_opts(:within_group=>expressions.freeze) 1474 end
Private Instance Methods
Set name, args, and opts
# File lib/sequel/sql.rb 1481 def _initialize(name, args, opts) 1482 @name = name 1483 @args = args.freeze 1484 @opts = opts.freeze 1485 freeze 1486 end
Function
uses a new! method for creating functions with options, since Function.new
does not allow for an options hash.
# File lib/sequel/extensions/eval_inspect.rb 139 def inspect_new_method 140 :new! 141 end
Return a new function call with the given opts merged into the current opts.
# File lib/sequel/sql.rb 1489 def with_opts(opts) 1490 self.class.new!(name, args, @opts.merge(opts)) 1491 end