---
{
    "title": "hex",
    "language": "zh-CN"
}
---

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# hex
## description
### Syntax

`VARCHAR hex(VARCHAR str)`

`VARCHAR hex(BIGINT num)`

如果输入参数是数字，返回十六进制值的字符串表示形式；

如果输入参数是字符串，则将每个字符转化为两个十六进制的字符，将转化后的所有字符拼接为字符串输出


## example

```
输入字符串

mysql> select hex('1');
+----------+
| hex('1') |
+----------+
| 31       |
+----------+

mysql> select hex('@');
+----------+
| hex('@') |
+----------+
| 40       |
+----------+

mysql> select hex('12');
+-----------+
| hex('12') |
+-----------+
| 3132      |
+-----------+
```

```
输入数字

mysql> select hex(12);
+---------+
| hex(12) |
+---------+
| C       |
+---------+

mysql> select hex(-1);
+------------------+
| hex(-1)          |
+------------------+
| FFFFFFFFFFFFFFFF |
+------------------+
```
## keyword
HEX