Array

True if the array is not empty and all of its elements are arrays of size 2, false otherwise. This is used to determine if the array could be a specifier of conditions, used similarly to a hash but allowing for duplicate keys and a specific order.

[].to_a.all_two_pairs? # => false
[:a].to_a.all_two_pairs? # => false
[[:b]].to_a.all_two_pairs? # => false
[[:a, 1]].to_a.all_two_pairs? # => true

# File lib/sequel/core_sql.rb, line 23
def all_two_pairs?
  !empty? && all?{|i| (Array === i) && (i.length == 2)}
end

Return a Sequel::SQL::CaseExpression with this array as the conditions and the given default value and expression.

[[{:a=>[2,3]}, 1]].case(0) # SQL: CASE WHEN a IN (2, 3) THEN 1 ELSE 0 END
[[:a, 1], [:b, 2]].case(:d, :c) # SQL: CASE c WHEN a THEN 1 WHEN b THEN 2 ELSE d END

# File lib/sequel/core_sql.rb, line 32
def case(default, expression = nil)
  ::Sequel::SQL::CaseExpression.new(self, default, expression)
end

Return a Sequel::SQL::Array created from this array. Used if this array contains all two pairs and you want it treated as an SQL array instead of a ordered hash-like conditions.

[[1, 2], [3, 4]] # SQL: 1 = 2 AND 3 = 4
[[1, 2], [3, 4]].sql_array # SQL: ((1, 2), (3, 4))

# File lib/sequel/core_sql.rb, line 42
def sql_array
  ::Sequel::SQL::SQLArray.new(self)
end

Return a Sequel::SQL::BooleanExpression created from this array, matching all of the conditions. Rarely do you need to call this explicitly, as Sequel generally assumes that arrays of all two pairs specify this type of condition.

[[:a, true]].sql_expr # SQL: a IS TRUE
[[:a, 1], [:b, [2, 3]]].sql_expr # SQL: a = 1 AND b IN (2, 3)

# File lib/sequel/core_sql.rb, line 52
def sql_expr
  sql_expr_if_all_two_pairs
end

Return a Sequel::SQL::BooleanExpression created from this array, matching none of the conditions.

[[:a, true]].sql_negate # SQL: a IS NOT TRUE
[[:a, 1], [:b, [2, 3]]].sql_negate # SQL: a != 1 AND b NOT IN (2, 3)

# File lib/sequel/core_sql.rb, line 61
def sql_negate
  sql_expr_if_all_two_pairs(:AND, true)
end

Return a Sequel::SQL::BooleanExpression created from this array, matching any of the conditions.

[[:a, true]].sql_or # SQL: a IS TRUE
[[:a, 1], [:b, [2, 3]]].sql_or # SQL: a = 1 OR b IN (2, 3)

# File lib/sequel/core_sql.rb, line 70
def sql_or
  sql_expr_if_all_two_pairs(:OR)
end

Return a Sequel::SQL::BooleanExpression representing an SQL string made up of the concatenation of this array’s elements. If an argument is passed it is used in between each element of the array in the SQL concatenation. This does not require that the array be made up of all two pairs.

[:a].sql_string_join # SQL: a
[:a, :b].sql_string_join # SQL: a || b
[:a, 'b'].sql_string_join # SQL: a || 'b'
['a', :b].sql_string_join(' ') # SQL: 'a' || ' ' || b

# File lib/sequel/core_sql.rb, line 83
def sql_string_join(joiner=nil)
  if joiner
    args = zip([joiner]*length).flatten
    args.pop
  else
    args = self
  end
  args = args.collect{|a| [Symbol, ::Sequel::SQL::Expression, ::Sequel::LiteralString, TrueClass, FalseClass, NilClass].any?{|c| a.is_a?(c)} ? a : a.to_s}
  ::Sequel::SQL::StringExpression.new(:'||', *args)
end

Return a Sequel::SQL::BooleanExpression created from this array, not matching all of the conditions.

~[[:a, true]] # SQL: a IS NOT TRUE
~[[:a, 1], [:b, [2, 3]]] # SQL: a != 1 OR b NOT IN (2, 3)

# File lib/sequel/core_sql.rb, line 10
def ~
  sql_expr_if_all_two_pairs(:OR, true)
end