index_object:count()

object index_object¶

index_object:count([key][, iterator])¶

Iterate over an index, counting the number of tuples which match the key-value.

Parameters:	index_object (index_object) – an object reference. key (scalar/table) – values to be matched against the index key iterator – comparison method
Return:	the number of matching tuples.
Rtype:	number

Example:

Below are few examples of using count. To try out these examples, you need to bootstrap a Tarantool database as described in Using data operations.

-- Insert test data -- box.space.bands:insert { 1, 'Roxette', 1986 } box.space.bands:insert { 2, 'Scorpions', 1965 } box.space.bands:insert { 3, 'Ace of Base', 1987 } box.space.bands:insert { 4, 'The Beatles', 1960 } box.space.bands:insert { 5, 'Pink Floyd', 1965 } box.space.bands:insert { 6, 'The Rolling Stones', 1962 } box.space.bands:insert { 7, 'The Doors', 1965 } box.space.bands:insert { 8, 'Nirvana', 1987 } box.space.bands:insert { 9, 'Led Zeppelin', 1968 } box.space.bands:insert { 10, 'Queen', 1970 } -- Count the number of tuples that match the full key value count = box.space.bands.index.year:count(1965) --[[ --- - 3 ... --]] -- Count the number of tuples that match the partial key value count_partial = box.space.bands.index.year_band:count(1965) --[[ --- - 3 ... --]]