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The tuple functions build fixed-length, ordered groups of values and operate on them element-wise. They are ClickHouse only, and tuple literals are written with struct(...) (re-cased to tuple(...) when the query runs on ClickHouse); PostgreSQL has no equivalent and rejects them.

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struct

Constructs a tuple literal from one or more values, letting you carry several columns as a single ordered value. This is the constructor you use everywhere a tuple is expected. There is no separate row(...) constructor — always write tuple literals as struct(...) (ClickHouse only). Syntax
Arguments
  • x1, x2, … — one or more values of any type. Element order is preserved.
Returned value
  • A tuple of the supplied values, Tuple(T1, T2, …). Extract a single element with tupleElement to export it as a scalar.
Example
Build a tuple and read one element

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tupleElement

Returns the n-th element (1-based) of a tuple (ClickHouse only). Syntax
Arguments
  • tuple — the tuple to read from, e.g. built with struct(...).
  • index — the 1-based position of the element to return (constant integer).
Returned value
  • The element at the given position; its type is the type of that tuple member.
Example
Read the second element

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tuplePlus

Performs element-wise addition of two numeric tuples of equal length (ClickHouse only). Syntax
Arguments
  • t1 — the first numeric tuple.
  • t2 — the second numeric tuple; must be the same length as t1.
Returned value
  • A tuple of the element-wise sums. Wrap it in tupleElement to export a single result as a scalar.
Example
Element-wise addition

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tupleMinus

Performs element-wise subtraction of two numeric tuples of equal length (ClickHouse only). Syntax
Arguments
  • t1 — the minuend tuple (numeric elements).
  • t2 — the subtrahend tuple; must be the same length as t1.
Returned value
  • A tuple of the element-wise differences. Wrap it in tupleElement to export a single result as a scalar.
Example
Element-wise subtraction

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tupleMultiply

Performs element-wise multiplication of two numeric tuples of equal length (ClickHouse only). Syntax
Arguments
  • t1 — the first numeric tuple.
  • t2 — the second numeric tuple; must be the same length as t1.
Returned value
  • A tuple of the element-wise products. Wrap it in tupleElement to export a single result as a scalar.
Example
Element-wise multiplication

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tupleNegate

Negates each element of a numeric tuple (ClickHouse only). Syntax
Arguments
  • t — a numeric tuple.
Returned value
  • A tuple with each element negated. Wrap it in tupleElement to export a single result as a scalar.
Example
Negate each element

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tupleHammingDistance

Counts the number of positions at which two tuples of equal length differ (ClickHouse only). Syntax
Arguments
  • t1 — the first tuple.
  • t2 — the second tuple; must be the same length as t1.
Returned value
  • The count of positions where the two tuples differ, as UInt64.
Example
Count differing positions