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---
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2022-04-10 23:08:18 +00:00
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sidebar_position: 191
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---
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# uniqExact {#agg_function-uniqexact}
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计算不同参数值的准确数目。
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**语法**
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``` sql
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uniqExact(x[, ...])
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```
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如果你绝对需要一个确切的结果，使用 `uniqExact` 函数。 否则使用 [uniq](../../../sql-reference/aggregate-functions/reference/uniq.md#agg_function-uniq) 函数。
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`uniqExact` 函数比 `uniq` 使用更多的内存，因为状态的大小随着不同值的数量的增加而无界增长。
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**参数**
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该函数采用可变数量的参数。 参数可以是 `Tuple`, `Array`, `Date`, `DateTime`, `String`，或数字类型。
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2021-03-05 13:14:08 +00:00
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**参见**
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- [uniq](../../../sql-reference/aggregate-functions/reference/uniq.md#agg_function-uniq)
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- [uniqCombined](../../../sql-reference/aggregate-functions/reference/uniq.md#agg_function-uniqcombined)
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- [uniqHLL12](../../../sql-reference/aggregate-functions/reference/uniq.md#agg_function-uniqhll12)
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