# Tuple(T1, T2, ...) A tuple of elements, each having an individual [type](index.md#data_types). You can't store tuples in tables (other than Memory tables). They are used for temporary column grouping. Columns can be grouped when an IN expression is used in a query, and for specifying certain formal parameters of lambda functions. For more information, see the sections [IN operators](../query_language/select.md#in_operators) and [Higher order functions](../query_language/functions/higher_order_functions.md#higher_order_functions). Tuples can be the result of a query. In this case, for text formats other than JSON, values are comma-separated in brackets. In JSON formats, tuples are output as arrays (in square brackets). ## Creating a tuple You can use a function to create a tuple: ``` tuple(T1, T2, ...) ``` Example of creating a tuple: ``` :) SELECT tuple(1,'a') AS x, toTypeName(x) SELECT (1, 'a') AS x, toTypeName(x) ┌─x───────┬─toTypeName(tuple(1, 'a'))─┐ │ (1,'a') │ Tuple(UInt8, String) │ └─────────┴───────────────────────────┘ 1 rows in set. Elapsed: 0.021 sec. ``` ## Working with data types When creating a tuple on the fly, ClickHouse automatically detects the type of each argument as the minimum of the types which can store the argument value. If the argument is [NULL](../query_language/syntax.md#null-literal), the type of the tuple element is [Nullable](nullable.md#data_type-nullable). Example of automatic data type detection: ``` SELECT tuple(1, NULL) AS x, toTypeName(x) SELECT (1, NULL) AS x, toTypeName(x) ┌─x────────┬─toTypeName(tuple(1, NULL))──────┐ │ (1,NULL) │ Tuple(UInt8, Nullable(Nothing)) │ └──────────┴─────────────────────────────────┘ 1 rows in set. Elapsed: 0.002 sec. ```