mirror of
https://github.com/ClickHouse/ClickHouse.git
synced 2024-11-24 08:32:02 +00:00
47 lines
550 B
Markdown
47 lines
550 B
Markdown
---
|
||
toc_priority: 128
|
||
---
|
||
|
||
# groupBitmap {#groupbitmap}
|
||
|
||
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)。
|
||
|
||
**语法**
|
||
|
||
``` sql
|
||
groupBitmap(expr)
|
||
```
|
||
|
||
**参数**
|
||
|
||
`expr` – 结果为 `UInt*` 类型的表达式。
|
||
|
||
**返回值**
|
||
|
||
`UInt64` 类型的值。
|
||
|
||
**示例**
|
||
|
||
测试数据:
|
||
|
||
``` text
|
||
UserID
|
||
1
|
||
1
|
||
2
|
||
3
|
||
```
|
||
|
||
查询:
|
||
|
||
``` sql
|
||
SELECT groupBitmap(UserID) as num FROM t
|
||
```
|
||
|
||
结果:
|
||
|
||
``` text
|
||
num
|
||
3
|
||
```
|