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# bitmap_hash
## description
### Syntax

`BITMAP BITMAP_HASH(expr)`

对任意类型的输入计算32位的哈希值，返回包含该哈希值的bitmap。主要用于stream load任务将非整型字段导入Doris表的bitmap字段。例如

```
cat data | curl --location-trusted -u user:passwd -T - -H "columns: dt,page,device_id, device_id=bitmap_hash(device_id)"   http://host:8410/api/test/testDb/_stream_load
```

## example

```
mysql> select bitmap_count(bitmap_hash('hello'));
+------------------------------------+
| bitmap_count(bitmap_hash('hello')) |
+------------------------------------+
|                                  1 |
+------------------------------------+
```

## keyword

    BITMAP_HASH,BITMAP