ClickHouse/docs/en/sql-reference/aggregate-functions/reference/avg.md

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avg

Calculates the arithmetic mean.

Syntax

avg(x)

Arguments

• x — Values.

x must be Integer, floating-point, or Decimal.

Returned value

• NaN if the supplied parameter is empty.
• Mean otherwise.

Return type is always Float64.

Example

Query:

SELECT avg(x) FROM values('x Int8', 0, 1, 2, 3, 4, 5)

Result:

┌─avg(x)─┐
│    2.5 │
└────────┘

Example

Query:

CREATE table test (t UInt8) ENGINE = Memory;
SELECT avg(t) FROM test

Result:

┌─avg(x)─┐
│    nan │
└────────┘