class Sequel::SQL::StringAgg

The StringAgg class represents an aggregate string concatentation.

Attributes

expr[R]

The string expression for each row that will concatenated to the output.

order_expr[R]

The expression that the aggregation is ordered by.

separator[R]

The separator between each string expression.

Public Class Methods

new(expr, separator=nil) { |self| ... } click to toggle source

Set the expression and separator

# File lib/sequel/extensions/string_agg.rb, line 147
def initialize(expr, separator=nil)
  @expr = expr
  @separator = separator
  yield self if block_given?
  freeze
end

Public Instance Methods

distinct() click to toggle source

Return a modified StringAgg that uses distinct expressions

# File lib/sequel/extensions/string_agg.rb, line 160
def distinct
  self.class.new(@expr, @separator) do |sa|
    sa.instance_variable_set(:@order_expr, @order_expr) if @order_expr
    sa.instance_variable_set(:@distinct, true)
  end
end
is_distinct?() click to toggle source

Whether the current expression uses distinct expressions

# File lib/sequel/extensions/string_agg.rb, line 155
def is_distinct?
  @distinct == true
end
order(*o) click to toggle source

Return a modified StringAgg with the given order

# File lib/sequel/extensions/string_agg.rb, line 168
def order(*o)
  self.class.new(@expr, @separator) do |sa|
    sa.instance_variable_set(:@distinct, @distinct) if @distinct
    sa.instance_variable_set(:@order_expr, o.empty? ? nil : o.freeze)
  end
end