space_object:pairs()
-
object
space_object
¶ -
space_object:
pairs
([key[, iterator]])¶ Search for a tuple or a set of tuples in the given space, and allow iterating over one tuple at a time. To search by the specific index, use the index_object:pairs() method.
Параметры: - space_object (
space_object
) – ссылка на объект - key (
scalar/table
) – значение должно совпасть с индексным ключом, который может быть составным - iterator – the iterator type. The default iterator type is „EQ“
- after – a tuple or the position of a tuple (tuple_pos) after which
pairs
starts the search. You can pass an empty string or box.NULL to this option to start the search from the first tuple.
возвращает: The iterator, which can be used in a
for/end
loop or with totable().Возможные ошибки:
- no such space
- wrong type
ER_TRANSACTION_CONFLICT
if a transaction conflict is detected in the MVCC transaction mode- iterator position is invalid
Факторы сложности: Размер индекса, тип индекса.
For information about iterators“ internal structures, see the «Lua Functional library» documentation.
Examples:
Below are few examples of using
pairs
with different parameters. To try out these examples, you need to bootstrap a Tarantool instance as described in Using data operations.-- Insert test data -- tarantool> bands:insert{1, 'Roxette', 1986} bands:insert{2, 'Scorpions', 1965} bands:insert{3, 'Ace of Base', 1987} bands:insert{4, 'The Beatles', 1960} bands:insert{5, 'Pink Floyd', 1965} bands:insert{6, 'The Rolling Stones', 1962} bands:insert{7, 'The Doors', 1965} bands:insert{8, 'Nirvana', 1987} bands:insert{9, 'Led Zeppelin', 1968} bands:insert{10, 'Queen', 1970} --- ... -- Select all tuples by the primary index -- tarantool> for _, tuple in bands:pairs() do print(tuple) end [1, 'Roxette', 1986] [2, 'Scorpions', 1965] [3, 'Ace of Base', 1987] [4, 'The Beatles', 1960] [5, 'Pink Floyd', 1965] [6, 'The Rolling Stones', 1962] [7, 'The Doors', 1965] [8, 'Nirvana', 1987] [9, 'Led Zeppelin', 1968] [10, 'Queen', 1970] --- ... -- Select all tuples whose primary key values are between 3 and 6 -- tarantool> for _, tuple in bands:pairs(3, {iterator = "GE"}) do if (tuple[1] > 6) then break end print(tuple) end [3, 'Ace of Base', 1987] [4, 'The Beatles', 1960] [5, 'Pink Floyd', 1965] [6, 'The Rolling Stones', 1962] --- ... -- Select all tuples after the specified tuple -- tarantool> for _, tuple in bands:pairs({}, {after={7, 'The Doors', 1965}}) do print(tuple) end [8, 'Nirvana', 1987] [9, 'Led Zeppelin', 1968] [10, 'Queen', 1970] --- ...
- space_object (
-