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48 lines
620 B
Markdown
48 lines
620 B
Markdown
---
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slug: /zh/sql-reference/aggregate-functions/reference/groupbitmap
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sidebar_position: 128
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---
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# groupBitmap {#groupbitmap}
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从无符号整数列进行位图或聚合计算，返回 `UInt64` 类型的基数，如果添加后缀 `State` ，则返回[位图对象](../../../sql-reference/functions/bitmap-functions.md)。
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**语法**
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``` sql
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groupBitmap(expr)
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```
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**参数**
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`expr` – 结果为 `UInt*` 类型的表达式。
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**返回值**
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`UInt64` 类型的值。
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**示例**
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测试数据:
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``` text
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UserID
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1
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1
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2
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3
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```
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查询:
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``` sql
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SELECT groupBitmap(UserID) as num FROM t
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```
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结果:
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``` text
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num
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3
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```
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