# DECODE function
<a name="DECODE"></a>

The DECODE function is the counterpart to the ENCODE function, which is used to convert a string to a binary format using a specific character encoding. The DECODE function takes the binary data and converts it back to a readable string format using the specified character encoding.

This function is useful when you need to work with binary data stored in a database and need to present it in a human-readable format, or when you need to convert data between different character encodings. 

## Syntax
<a name="DECODE-syntax"></a>

```
decode(expr, charset)
```

## Arguments
<a name="DECODE-arguments"></a>

 *expr*   
A BINARY expression encoded in charset.

 *charset*   
A STRING expression.  
Supported character set encodings (case-insensitive): `'US-ASCII'`, `'ISO-8859-1'`, `'UTF-8'`, `'UTF-16BE'`, `'UTF-16LE'`, and `'UTF-16'`.

## Return type
<a name="DECODE-return-type"></a>

The DECODE function returns a STRING.

## Example
<a name="DECODE-example"></a>

The following example has a table called `messages` with a column called `message_text` that stores message data in a binary format using the UTF-8 character encoding. The DECODE function converts the binary data back to a readable string format. The output of this query is the readable text of the message stored in the messages table, with the ID `123`, converted from the binary format to a string using the `'utf-8'` encoding.

```
SELECT decode(message_text, 'utf-8') AS message
FROM messages
WHERE message_id = 123;
```