--- slug: /en/sql-reference/functions/tuple-functions sidebar_position: 180 sidebar_label: Tuples --- ## tuple A function that allows grouping multiple columns. For columns with the types T1, T2, …, it returns a Tuple(T1, T2, …) type tuple containing these columns. There is no cost to execute the function. Tuples are normally used as intermediate values for an argument of IN operators, or for creating a list of formal parameters of lambda functions. Tuples can’t be written to a table. The function implements the operator `(x, y, …)`. **Syntax** ``` sql tuple(x, y, …) ``` ## tupleElement A function that allows getting a column from a tuple. If the second argument is a number `index`, it is the column index, starting from 1. If the second argument is a string `name`, it represents the name of the element. Besides, we can provide the third optional argument, such that when index out of bounds or no element exist for the name, the default value returned instead of throwing an exception. The second and third arguments, if provided, must be constants. There is no cost to execute the function. The function implements operators `x.index` and `x.name`. **Syntax** ``` sql tupleElement(tuple, index, [, default_value]) tupleElement(tuple, name, [, default_value]) ``` ## untuple Performs syntactic substitution of [tuple](../../sql-reference/data-types/tuple.md#tuplet1-t2) elements in the call location. The names of the result columns are implementation-specific and subject to change. Do not assume specific column names after `untuple`. **Syntax** ``` sql untuple(x) ``` You can use the `EXCEPT` expression to skip columns as a result of the query. **Arguments** - `x` — A `tuple` function, column, or tuple of elements. [Tuple](../../sql-reference/data-types/tuple.md). **Returned value** - None. **Examples** Input table: ``` text ┌─key─┬─v1─┬─v2─┬─v3─┬─v4─┬─v5─┬─v6────────┐ │ 1 │ 10 │ 20 │ 40 │ 30 │ 15 │ (33,'ab') │ │ 2 │ 25 │ 65 │ 70 │ 40 │ 6 │ (44,'cd') │ │ 3 │ 57 │ 30 │ 20 │ 10 │ 5 │ (55,'ef') │ │ 4 │ 55 │ 12 │ 7 │ 80 │ 90 │ (66,'gh') │ │ 5 │ 30 │ 50 │ 70 │ 25 │ 55 │ (77,'kl') │ └─────┴────┴────┴────┴────┴────┴───────────┘ ``` Example of using a `Tuple`-type column as the `untuple` function parameter: Query: ``` sql SELECT untuple(v6) FROM kv; ``` Result: ``` text ┌─_ut_1─┬─_ut_2─┐ │ 33 │ ab │ │ 44 │ cd │ │ 55 │ ef │ │ 66 │ gh │ │ 77 │ kl │ └───────┴───────┘ ``` Example of using an `EXCEPT` expression: Query: ``` sql SELECT untuple((* EXCEPT (v2, v3),)) FROM kv; ``` Result: ``` text ┌─key─┬─v1─┬─v4─┬─v5─┬─v6────────┐ │ 1 │ 10 │ 30 │ 15 │ (33,'ab') │ │ 2 │ 25 │ 40 │ 6 │ (44,'cd') │ │ 3 │ 57 │ 10 │ 5 │ (55,'ef') │ │ 4 │ 55 │ 80 │ 90 │ (66,'gh') │ │ 5 │ 30 │ 25 │ 55 │ (77,'kl') │ └─────┴────┴────┴────┴───────────┘ ``` **See Also** - [Tuple](../../sql-reference/data-types/tuple.md) ## tupleHammingDistance Returns the [Hamming Distance](https://en.wikipedia.org/wiki/Hamming_distance) between two tuples of the same size. **Syntax** ``` sql tupleHammingDistance(tuple1, tuple2) ``` **Arguments** - `tuple1` — First tuple. [Tuple](../../sql-reference/data-types/tuple.md). - `tuple2` — Second tuple. [Tuple](../../sql-reference/data-types/tuple.md). Tuples should have the same type of the elements. **Returned value** - The Hamming distance. Type: The result type is calculated the same way it is for [Arithmetic functions](../../sql-reference/functions/arithmetic-functions.md), based on the number of elements in the input tuples. ``` sql SELECT toTypeName(tupleHammingDistance(tuple(0), tuple(0))) AS t1, toTypeName(tupleHammingDistance((0, 0), (0, 0))) AS t2, toTypeName(tupleHammingDistance((0, 0, 0), (0, 0, 0))) AS t3, toTypeName(tupleHammingDistance((0, 0, 0, 0), (0, 0, 0, 0))) AS t4, toTypeName(tupleHammingDistance((0, 0, 0, 0, 0), (0, 0, 0, 0, 0))) AS t5 ``` ``` text ┌─t1────┬─t2─────┬─t3─────┬─t4─────┬─t5─────┐ │ UInt8 │ UInt16 │ UInt32 │ UInt64 │ UInt64 │ └───────┴────────┴────────┴────────┴────────┘ ``` **Examples** Query: ``` sql SELECT tupleHammingDistance((1, 2, 3), (3, 2, 1)) AS HammingDistance; ``` Result: ``` text ┌─HammingDistance─┐ │ 2 │ └─────────────────┘ ``` Can be used with [MinHash](../../sql-reference/functions/hash-functions.md#ngramminhash) functions for detection of semi-duplicate strings: ``` sql SELECT tupleHammingDistance(wordShingleMinHash(string), wordShingleMinHashCaseInsensitive(string)) as HammingDistance FROM (SELECT 'ClickHouse is a column-oriented database management system for online analytical processing of queries.' AS string); ``` Result: ``` text ┌─HammingDistance─┐ │ 2 │ └─────────────────┘ ``` ## tupleToNameValuePairs Turns a named tuple into an array of (name, value) pairs. For a `Tuple(a T, b T, ..., c T)` returns `Array(Tuple(String, T), ...)` in which the `Strings` represents the named fields of the tuple and `T` are the values associated with those names. All values in the tuple should be of the same type. **Syntax** ``` sql tupleToNameValuePairs(tuple) ``` **Arguments** - `tuple` — Named tuple. [Tuple](../../sql-reference/data-types/tuple.md) with any types of values. **Returned value** - An array with (name, value) pairs. Type: [Array](../../sql-reference/data-types/array.md)([Tuple](../../sql-reference/data-types/tuple.md)([String](../../sql-reference/data-types/string.md), ...)). **Example** Query: ``` sql CREATE TABLE tupletest (col Tuple(user_ID UInt64, session_ID UInt64)) ENGINE = Memory; INSERT INTO tupletest VALUES (tuple( 100, 2502)), (tuple(1,100)); SELECT tupleToNameValuePairs(col) FROM tupletest; ``` Result: ``` text ┌─tupleToNameValuePairs(col)────────────┐ │ [('user_ID',100),('session_ID',2502)] │ │ [('user_ID',1),('session_ID',100)] │ └───────────────────────────────────────┘ ``` It is possible to transform columns to rows using this function: ``` sql CREATE TABLE tupletest (col Tuple(CPU Float64, Memory Float64, Disk Float64)) ENGINE = Memory; INSERT INTO tupletest VALUES(tuple(3.3, 5.5, 6.6)); SELECT arrayJoin(tupleToNameValuePairs(col)) FROM tupletest; ``` Result: ``` text ┌─arrayJoin(tupleToNameValuePairs(col))─┐ │ ('CPU',3.3) │ │ ('Memory',5.5) │ │ ('Disk',6.6) │ └───────────────────────────────────────┘ ``` If you pass a simple tuple to the function, ClickHouse uses the indexes of the values as their names: ``` sql SELECT tupleToNameValuePairs(tuple(3, 2, 1)); ``` Result: ``` text ┌─tupleToNameValuePairs(tuple(3, 2, 1))─┐ │ [('1',3),('2',2),('3',1)] │ └───────────────────────────────────────┘ ``` ## tuplePlus Calculates the sum of corresponding values of two tuples of the same size. **Syntax** ```sql tuplePlus(tuple1, tuple2) ``` Alias: `vectorSum`. **Arguments** - `tuple1` — First tuple. [Tuple](../../sql-reference/data-types/tuple.md). - `tuple2` — Second tuple. [Tuple](../../sql-reference/data-types/tuple.md). **Returned value** - Tuple with the sum. Type: [Tuple](../../sql-reference/data-types/tuple.md). **Example** Query: ```sql SELECT tuplePlus((1, 2), (2, 3)); ``` Result: ```text ┌─tuplePlus((1, 2), (2, 3))─┐ │ (3,5) │ └───────────────────────────┘ ``` ## tupleMinus Calculates the subtraction of corresponding values of two tuples of the same size. **Syntax** ```sql tupleMinus(tuple1, tuple2) ``` Alias: `vectorDifference`. **Arguments** - `tuple1` — First tuple. [Tuple](../../sql-reference/data-types/tuple.md). - `tuple2` — Second tuple. [Tuple](../../sql-reference/data-types/tuple.md). **Returned value** - Tuple with the result of subtraction. Type: [Tuple](../../sql-reference/data-types/tuple.md). **Example** Query: ```sql SELECT tupleMinus((1, 2), (2, 3)); ``` Result: ```text ┌─tupleMinus((1, 2), (2, 3))─┐ │ (-1,-1) │ └────────────────────────────┘ ``` ## tupleMultiply Calculates the multiplication of corresponding values of two tuples of the same size. **Syntax** ```sql tupleMultiply(tuple1, tuple2) ``` **Arguments** - `tuple1` — First tuple. [Tuple](../../sql-reference/data-types/tuple.md). - `tuple2` — Second tuple. [Tuple](../../sql-reference/data-types/tuple.md). **Returned value** - Tuple with the multiplication. Type: [Tuple](../../sql-reference/data-types/tuple.md). **Example** Query: ```sql SELECT tupleMultiply((1, 2), (2, 3)); ``` Result: ```text ┌─tupleMultiply((1, 2), (2, 3))─┐ │ (2,6) │ └───────────────────────────────┘ ``` ## tupleDivide Calculates the division of corresponding values of two tuples of the same size. Note that division by zero will return `inf`. **Syntax** ```sql tupleDivide(tuple1, tuple2) ``` **Arguments** - `tuple1` — First tuple. [Tuple](../../sql-reference/data-types/tuple.md). - `tuple2` — Second tuple. [Tuple](../../sql-reference/data-types/tuple.md). **Returned value** - Tuple with the result of division. Type: [Tuple](../../sql-reference/data-types/tuple.md). **Example** Query: ```sql SELECT tupleDivide((1, 2), (2, 3)); ``` Result: ```text ┌─tupleDivide((1, 2), (2, 3))─┐ │ (0.5,0.6666666666666666) │ └─────────────────────────────┘ ``` ## tupleNegate Calculates the negation of the tuple values. **Syntax** ```sql tupleNegate(tuple) ``` **Arguments** - `tuple` — [Tuple](../../sql-reference/data-types/tuple.md). **Returned value** - Tuple with the result of negation. Type: [Tuple](../../sql-reference/data-types/tuple.md). **Example** Query: ```sql SELECT tupleNegate((1, 2)); ``` Result: ```text ┌─tupleNegate((1, 2))─┐ │ (-1,-2) │ └─────────────────────┘ ``` ## tupleMultiplyByNumber Returns a tuple with all values multiplied by a number. **Syntax** ```sql tupleMultiplyByNumber(tuple, number) ``` **Arguments** - `tuple` — [Tuple](../../sql-reference/data-types/tuple.md). - `number` — Multiplier. [Int/UInt](../../sql-reference/data-types/int-uint.md), [Float](../../sql-reference/data-types/float.md) or [Decimal](../../sql-reference/data-types/decimal.md). **Returned value** - Tuple with multiplied values. Type: [Tuple](../../sql-reference/data-types/tuple.md). **Example** Query: ```sql SELECT tupleMultiplyByNumber((1, 2), -2.1); ``` Result: ```text ┌─tupleMultiplyByNumber((1, 2), -2.1)─┐ │ (-2.1,-4.2) │ └─────────────────────────────────────┘ ``` ## tupleDivideByNumber Returns a tuple with all values divided by a number. Note that division by zero will return `inf`. **Syntax** ```sql tupleDivideByNumber(tuple, number) ``` **Arguments** - `tuple` — [Tuple](../../sql-reference/data-types/tuple.md). - `number` — Divider. [Int/UInt](../../sql-reference/data-types/int-uint.md), [Float](../../sql-reference/data-types/float.md) or [Decimal](../../sql-reference/data-types/decimal.md). **Returned value** - Tuple with divided values. Type: [Tuple](../../sql-reference/data-types/tuple.md). **Example** Query: ```sql SELECT tupleDivideByNumber((1, 2), 0.5); ``` Result: ```text ┌─tupleDivideByNumber((1, 2), 0.5)─┐ │ (2,4) │ └──────────────────────────────────┘ ``` ## dotProduct Calculates the scalar product of two tuples of the same size. **Syntax** ```sql dotProduct(tuple1, tuple2) ``` Alias: `scalarProduct`. **Arguments** - `tuple1` — First tuple. [Tuple](../../sql-reference/data-types/tuple.md). - `tuple2` — Second tuple. [Tuple](../../sql-reference/data-types/tuple.md). **Returned value** - Scalar product. Type: [Int/UInt](../../sql-reference/data-types/int-uint.md), [Float](../../sql-reference/data-types/float.md) or [Decimal](../../sql-reference/data-types/decimal.md). **Example** Query: ```sql SELECT dotProduct((1, 2), (2, 3)); ``` Result: ```text ┌─dotProduct((1, 2), (2, 3))─┐ │ 8 │ └────────────────────────────┘ ``` ## tupleConcat Combines tuples passed as arguments. ``` sql tupleConcat(tuples) ``` **Arguments** - `tuples` – Arbitrary number of arguments of [Tuple](../../sql-reference/data-types/tuple.md) type. **Example** ``` sql SELECT tupleConcat((1, 2), (3, 4), (true, false)) AS res ``` ``` text ┌─res──────────────────┐ │ (1,2,3,4,true,false) │ └──────────────────────┘ ``` ## Distance functions All supported functions are described in [distance functions documentation](../../sql-reference/functions/distance-functions.md).