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, line 1375 def initialize(name, *args) _initialize(name, args, OPTS) 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, line 1387 def *(ce=(arg=false;nil)) if arg == false raise Error, "Cannot apply * to functions with arguments" unless args.empty? with_opts(:"*"=>true) else super(ce) end end
Return a new function with DISTINCT before the method arguments.
Sequel.function(:count, :col).distinct # count(DISTINCT col)
# File lib/sequel/sql.rb, line 1399 def distinct with_opts(:distinct=>true) 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, line 1407 def filter(*args, &block) if args.length == 1 args = args.first else args.freeze end with_opts(:filter=>args, :filter_block=>block) end
Return a function which will use LATERAL when literalized:
Sequel.function(:foo, :col).lateral # LATERAL foo(col)
# File lib/sequel/sql.rb, line 1420 def lateral with_opts(:lateral=>true) 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, line 1428 def order(*args) with_opts(:order=>args.freeze) 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, line 1436 def over(window=OPTS) raise Error, "function already has a window applied to it" if opts[:over] window = Window.new(window) unless window.is_a?(Window) with_opts(:over=>window) 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, line 1446 def quoted with_opts(:quoted=>true) 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, line 1454 def unquoted with_opts(:quoted=>false) 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, line 1462 def with_ordinality with_opts(:with_ordinality=>true) 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, line 1471 def within_group(*expressions) with_opts(:within_group=>expressions.freeze) end
Private Instance Methods
Set name, args, and opts
# File lib/sequel/sql.rb, line 1480 def _initialize(name, args, opts) @name = name @args = args.freeze @opts = opts.freeze freeze end
Return a new function call with the given opts merged into the current opts.
# File lib/sequel/sql.rb, line 1488 def with_opts(opts) self.class.new!(name, args, @opts.merge(opts)) end