ClickHouse/docs/zh/sql-reference/aggregate-functions/reference/avgweighted.md

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---
toc_priority: 107
---
# avgWeighted {#avgweighted}
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计算 [加权算术平均值](https://en.wikipedia.org/wiki/Weighted_arithmetic_mean)。
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**语法**
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``` sql
avgWeighted(x, weight)
```
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**参数**
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- `x` — 值。
- `weight` — 值的加权。
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`x``weight` 的类型必须是
[整数](../../../sql-reference/data-types/int-uint.md), 或
[浮点数](../../../sql-reference/data-types/float.md), 或
[定点数](../../../sql-reference/data-types/decimal.md),
但是可以不一样。
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**返回值**
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- `NaN`。 如果所有的权重都等于0 或所提供的权重参数是空。
- 加权平均值。 其他。
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类型: 总是[Float64](../../../sql-reference/data-types/float.md).
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**示例**
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查询:
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``` sql
SELECT avgWeighted(x, w)
FROM values('x Int8, w Int8', (4, 1), (1, 0), (10, 2))
```
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结果:
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``` text
┌─avgWeighted(x, weight)─┐
│ 8 │
└────────────────────────┘
```
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**示例**
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查询:
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``` sql
SELECT avgWeighted(x, w)
FROM values('x Int8, w Int8', (0, 0), (1, 0), (10, 0))
```
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结果:
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``` text
┌─avgWeighted(x, weight)─┐
│ nan │
└────────────────────────┘
```
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**示例**
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查询:
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``` sql
CREATE table test (t UInt8) ENGINE = Memory;
SELECT avgWeighted(t) FROM test
```
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结果:
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``` text
┌─avgWeighted(x, weight)─┐
│ nan │
└────────────────────────┘
```