class Array

  1. lib/sequel/extensions/core_extensions.rb
Parent: core_extensions.rb

Sequel extends Array to add methods to implement the SQL DSL. Most of these methods require that the array not be empty and that it must consist solely of other arrays that have exactly two elements.

Public Instance Aliases

sql_array -> sql_value_list

Public Instance methods

case (*args)

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
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# File lib/sequel/extensions/core_extensions.rb, line 35
def case(*args)
  ::Sequel::SQL::CaseExpression.new(self, *args)
end
sql_expr ()

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 two element arrays specify this type of condition. One case where it can be necessary to use this is if you are using the object as a value in a filter hash and want to use the = operator instead of the IN operator (which is used by default for arrays of two element arrays).

[[:a, true]].sql_expr # SQL: a IS TRUE
[[:a, 1], [:b, [2, 3]]].sql_expr # SQL: a = 1 AND b IN (2, 3)
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# File lib/sequel/extensions/core_extensions.rb, line 62
def sql_expr
  Sequel.expr(self)
end
sql_negate ()

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)
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# File lib/sequel/extensions/core_extensions.rb, line 71
def sql_negate
  Sequel.negate(self)
end
sql_or ()

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)
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# File lib/sequel/extensions/core_extensions.rb, line 80
def sql_or
  Sequel.or(self)
end
sql_string_join (joiner=nil)

Return a Sequel::SQL::StringExpression 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.

[: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
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# File lib/sequel/extensions/core_extensions.rb, line 93
def sql_string_join(joiner=nil)
  Sequel.join(self, joiner)
end
sql_value_list ()

Return a Sequel::SQL::ValueList created from this array. Used if this array contains all two element arrays and you want it treated as an SQL value list (IN predicate) instead of as a conditions specifier (similar to a hash). This is not necessary if you are using this array as a value in a filter, but may be necessary if you are using it as a value with placeholder SQL:

DB[:a].filter([:a, :b]=>[[1, 2], [3, 4]]) # SQL: (a, b) IN ((1, 2), (3, 4))
DB[:a].filter('(a, b) IN ?', [[1, 2], [3, 4]]) # SQL: (a, b) IN ((1 = 2) AND (3 = 4))
DB[:a].filter('(a, b) IN ?', [[1, 2], [3, 4]].sql_value_list) # SQL: (a, b) IN ((1, 2), (3, 4))
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# File lib/sequel/extensions/core_extensions.rb, line 48
def sql_value_list
  ::Sequel::SQL::ValueList.new(self)
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)
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# File lib/sequel/extensions/core_extensions.rb, line 26
def ~
  Sequel.~(self)
end