---
{
    "title": "bitmap_hash",
    "language": "en"
}
---

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# bitmap_hash
## description
### Syntax

`BITMAP BITMAP_HASH(expr)`

Compute the 32-bits hash value of a expr of any type, then return a bitmap containing that hash value. Mainly be used to load non-integer value into bitmap column, e.g.,

```
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