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63 lines
878 B
Markdown
63 lines
878 B
Markdown
---
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toc_priority: 5
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---
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# avg {#agg_function-avg}
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Calculates the arithmetic mean.
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**Syntax**
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``` sql
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avg(x)
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```
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**Arguments**
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- `x` — Values.
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`x` must be
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[Integer](../../../sql-reference/data-types/int-uint.md),
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[floating-point](../../../sql-reference/data-types/float.md), or
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[Decimal](../../../sql-reference/data-types/decimal.md).
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**Returned value**
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- `NaN` if the supplied parameter is empty.
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- Mean otherwise.
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**Return type** is always [Float64](../../../sql-reference/data-types/float.md).
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**Example**
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Query:
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``` sql
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SELECT avg(x) FROM values('x Int8', 0, 1, 2, 3, 4, 5)
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```
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Result:
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``` text
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┌─avg(x)─┐
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│ 2.5 │
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└────────┘
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```
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**Example**
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Query:
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``` sql
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CREATE table test (t UInt8) ENGINE = Memory;
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SELECT avg(t) FROM test
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```
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Result:
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``` text
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┌─avg(x)─┐
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│ nan │
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└────────┘
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```
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